TC1044S

/var/www/html/datasheet/sites/default/files/pdfhtml_dummy/21348a-html.html
background image

TC1044S

TC1044S-12  9/16/96

EVALUATION

KIT

AVAILABLE

© 2001 Microchip Technology Inc.     DS21348A

Charge Pump DC-TO-DC Voltage Converter

FEATURES

Converts +5V Logic Supply to 

±

5V System

Wide Input Voltage Range .................... 1.5V to 12V

Efficient Voltage Conversion ......................... 99.9%

Excellent Power Efficiency ............................... 98%

Low Power Consumption ............ 80

µ

A @ V

IN

 = 5V

Low Cost and Easy to Use
— Only Two External Capacitors Required

RS-232 Negative Power Supply

Available in 8-Pin Small Outline (SOIC) and 8-Pin
Plastic DIP Packages

Improved ESD Protection ..................... Up to 10kV

No External Diode Required for High Voltage
Operation

Frequency Boost Raises F

OSC

 to 45kHz

GENERAL DESCRIPTION

The TC1044S is a pin-compatible upgrade to the Indus-

try standard TC7660 charge pump voltage converter. It
converts a +1.5V to +12V input to a corresponding –1.5V
to –12V output using only two low cost capacitors, eliminat-
ing inductors and their associated cost, size and EMI.
Added features include an extended supply range to 12V,
and a frequency boost pin for higher operating frequency,
allowing the use of smaller external capacitors.

The on-board oscillator operates at a nominal frequency

of 10kHz. Frequency is increased to 45kHz when pin 1 is
connected to V

+

.  Operation below 10kHz (for lower supply

current applications) is possible by connecting an external
capacitor from OSC to ground (with pin 1 open).

The TC1044S is available in both 8-pin DIP and

8-pin small outline (SOIC) packages in commercial and
extended temperature ranges.

FUNCTIONAL BLOCK DIAGRAM

TC1044S

GND

INTERNAL

VOLTAGE

REGULATOR

RC

OSCILLATOR

VOLTAGE–

LEVEL

TRANSLATOR

2

V +

CAP +

8

2

7

6

OSC

LV

3

LOGIC

NETWORK

VOUT

5

CAP –

4

1

BOOST

ORDERING INFORMATION

Part No.

Package

 Temp. Range

TC1044SCOA

8-Pin SOIC

0

°

C to +70

°

C

TC1044SCPA

8-Pin Plastic DIP

0

°

C to +70

°

C

TC1044SEOA

8-Pin SOIC

– 40

°

C to +85

°

C

TC1044SEPA

8-Pin Plastic DIP

– 40

°

C to +85

°

C

TC1044SIJA

8-Pin CerDIP

– 25

°

C to +85

°

C

TC1044SMJA

8-Pin CerDIP

– 55

°

C to +125

°

C

TC7660EV

Charge Pump Family Evaluation Kit

PIN CONFIGURATION (DIP AND SOIC)

1

2

3

4

8

7

6

5

TC1044SCPA
TC1044SEPA

TC1044SIJA

TC1044SMJA

BOOST

CAP +

GND

CAP –

VOUT

LOW
VOLTAGE (LV)

OSC

+

V

1

2

3

4

8

7

6

5

TC1044SCOA

TC1044SEOA

BOOST

CAP +

GND

CAP –

VOUT

LOW
VOLTAGE (LV)

OSC

+

V

/var/www/html/datasheet/sites/default/files/pdfhtml_dummy/21348a-html.html
background image

TC1044S-12  9/16/96

TC1044S

Charge Pump DC-TO-DC Voltage Converter

2

© 2001 Microchip Technology Inc.     DS21348A

Package Power Dissipation (T

A

 

 70

°

C) (Note 2)

8-Pin CerDIP .................................................. 800mW
8-Pin Plastic DIP ............................................. 730mW
8-Pin SOIC ..................................................... 470mW

Operating Temperature Range

C Suffix .................................................. 0

°

C to +70

°

C

I Suffix ............................................... – 25

°

C to +85

°

C

E Suffix ............................................. – 40

°

C to +85

°

C

M Suffix ........................................... – 55

°

C to +125

°

C

Storage Temperature Range ................ – 65

°

C to +150

°

C

ELECTRICAL CHARACTERISTICS:

T

A

 = +25

°

C, V

+

 = 5V, C

OSC

 = 0, Test Circuit (Figure 1), unless otherwise

indicated.

Symbol

Parameter

Test Conditions

Min

Typ

Max

Unit

I

+

Supply Current

R

L

 = 

80

160

µ

A

0

°

C < T

A

 < +70

°

C

180

– 40

°

C < T

A

 < +85

°

C

180

– 55

°

C < T

A

 < +125

°

C

200

I

+

Supply Current

0

°

C < T

A

 < +70

°

C

300

µ

A

(Boost Pin = V

+

)

–  40

°

C < T

A

 < +85

°

C

350

– 55

°

C < T

A

 < +125

°

C

400

V

+

H2

Supply Voltage Range, High

Min 

 T

A

 

 Max,

3

12

V

R

L

 = 10 k

, LV Open

V

+

L2

Supply Voltage Range, Low

Min 

 T

A

 

 Max,

1.5

3.5

V

R

L

 = 10 k

, LV to GND

R

OUT

Output Source Resistance

I

OUT

 = 20mA

60

100

I

OUT

 = 20mA, 0

°

 T

A

 

 +70

°

C

70

120

I

OUT

 = 20mA, –40

°

 T

A

 

 +85

°

C

70

120

I

OUT

 = 20mA, –55

°

 T

A

 

 +125

°

C

105

150

V

+

 = 2V, I

OUT

 = 3 mA, LV to GND

0

°

 T

A

 

 +70

°

C

250

– 55

°

 T

A

 

 +125

°

C

400

F

OSC

Oscillator Frequency

Pin 7 open; Pin 1 open or GND

10

kHz

Boost Pin = V

+

45

P

EFF

Power Efficiency

R

L

 = 5 k

; Boost Pin Open

96

98

%

T

MIN

 < T

A

 < T

MAX

; Boost Pin Open

95

97

Boost Pin = V

+

88

V

OUT 

E

FF

Voltage Conversion Efficiency

R

L

 = 

99

99.9

%

Z

OSC

Oscillator Impedance

V

+

 = 2V

1

M

V

+

 = 5V

100

k

NOTES: 1. Connecting any input terminal to voltages greater than V

+

 or less than GND may cause destructive latch-up. It is recommended that no

inputs from sources operating from external supplies be applied prior to "power up" of the TC1044S.

2. Derate linearly above 50

°

C by 5.5mW/

°

C.

ABSOLUTE MAXIMUM RATINGS*

Supply Voltage ......................................................... +13V
LV, Boost and OSC Inputs

Voltage (Note 1) ......................... – 0.3V to (V

+

+ 0.3V)

for V

+

 < 5.5V

(V

– 5.5V) to (V

+

+ 0.3V)

for V

+

 > 5.5V

Current Into LV (Note 1) ...................... 20

µ

A for V

+

 > 3.5V

Output Short Duration (V

SUPPLY

 

 5.5V) ......... Continuous

Lead Temperature (Soldering, 10 sec) ................. +300

°

C

*Static-sensitive device. Unused devices must be stored in conductive material. Protect devices from static discharge and static fields. Stresses above those
listed under "Absolute Maximum Ratings" may cause permanent damage to the device. These are stress ratings only and functional operation of the device
at these or any other conditions above those indicated in the operation sections of the specifications is not implied.  Exposure to absolute maximum rating
conditions for extended periods may affect device reliability.

/var/www/html/datasheet/sites/default/files/pdfhtml_dummy/21348a-html.html
background image

3

TC1044S

Charge Pump DC-TO-DC Voltage Converter

TC1044S-12  9/16/96

© 2001 Microchip Technology Inc.     DS21348A

Circuit Description

The TC1044S contains all the necessary circuitry to

implement a voltage inverter, with the exception of two
external capacitors, which may be inexpensive 10 

µ

F polar-

ized electrolytic capacitors. Operation is best understood by
considering Figure 2, which shows an idealized voltage
inverter. Capacitor C

1

 is charged to a voltage, V

+

, for the half

cycle when switches S

1

 and S

3

 are closed. (Note: Switches

S

2

 and S

4

 are open during this half cycle.) During the second

half cycle of operation, switches S

2

 and S

4

 are closed, with

S

1

 and S

3

 open, thereby shifting capacitor C

1

 negatively by

V

+

 volts. Charge is then transferred from C

1

 to C

2

, such that

the voltage on C

2

 is exactly V

+

, assuming ideal switches and

no load on C

2

.

The four switches in Figure 2 are MOS power switches;

S

1

 is a P-channel device, and S

2

, S

3

 and S

4

 are N-channel

devices. The main difficulty with this approach is that in
integrating the switches, the substrates of S

3

 and S

4

 must

always remain reverse-biased with respect to their sources,
but not so much as to degrade their ON resistances. In
addition, at circuit start-up, and under output short circuit
conditions (V

OUT

 = V

+

), the output voltage must be sensed

and the substrate bias adjusted accordingly. Failure to
accomplish this will result in high power losses and probable
device latch-up.

This problem is eliminated in the TC1044S by a logic

network which senses the output voltage (V

OUT

) together

with the level translators, and switches the substrates of
S

3

 and S

4

 to the correct level to maintain necessary reverse

bias.

Figure 2.  Idealized Charge Pump Inverter

V+

GND

S3

S1

S2

S4

C2

VOUT = – VIN

C1

The voltage regulator portion of the TC1044S is an

integral part of the anti-latch-up circuitry. Its inherent voltage
drop can, however, degrade operation at low voltages. To
improve low-voltage operation, the “LV” pin should be
connected to GND, disabling the regulator. For supply
voltages greater than 3.5V, the LV terminal must be left
open to ensure latch-up-proof operation and prevent device
damage.

Theoretical Power Efficiency
Considerations

In theory, a capacitive charge pump can approach

100% efficiency if certain conditions are met:

(1) The drive circuitry consumes minimal power.

(2) The output switches have extremely low ON

resistance and virtually no offset.

(3) The impedances of the pump and reservoir

capacitors are negligible at the pump frequency.

The TC1044S approaches these conditions for nega-

tive voltage multiplication if large values of C

1

 and C

2

 are

used.  Energy is lost only in the transfer of charge
between capacitors if a change in voltage occurs. 
The
energy lost is defined by:

E = 1/2 C

1

 (V

1

2

 – V

2

2

)

V

1

 and V

2

 are the voltages on C

1

 during the pump and

transfer cycles. If the impedances of C

1

 and C

2

 are relatively

high at the pump frequency (refer to Figure 2) compared to
the value of R

L

, there will be a substantial difference in

voltages V

1

 and V

2

. Therefore, it is desirable not only to

make C

2

 as large as possible to eliminate output voltage

ripple, but also to employ a correspondingly large value for
C

1

 in order to achieve maximum efficiency of operation.

1

2

3

4

8

7

6

5

TC1044S

+

V+

(+5V)

VOUT

C1

1

µ

F

COSC

*

+

C2

10

µ

F

IL

RL

IS

V+

NOTE:   For large values of C

OSC

 (>1000pF), the values 

of C

1

 and C

2

 should be increased to 100

µ

F.

Figure 1.  TC1044S Test Circuit

/var/www/html/datasheet/sites/default/files/pdfhtml_dummy/21348a-html.html
background image

TC1044S-12  9/16/96

TC1044S

Charge Pump DC-TO-DC Voltage Converter

4

© 2001 Microchip Technology Inc.     DS21348A

The output characteristics of the circuit in Figure 3 are

those of a nearly ideal voltage source in series with 70

.

Thus, for a load current of –10mA and a supply voltage of
+5V, the output voltage would be – 4.3V.

The dynamic output impedance of the TC1044S is due,

primarily, to capacitive reactance of the charge transfer
capacitor (C

1

). Since this capacitor is connected to the

output for only 1/2 of the cycle, the equation is:

Paralleling Devices

Any number of TC1044S voltage converters may be

paralleled to reduce output resistance (Figure 4). The reser-
voir capacitor, C

2

, serves all devices, while each device

requires its own pump capacitor, C

1

. The resultant output

resistance would be approximately:

2

2

π

f

 

C

1

    X

=               = 3.18

Ω,

where f = 10 kHz and C

= 10

µ

F.

Figure 4.  Paralleling Devices Lowers Output Impedance

1

2

3

4

8

7

6

5

TC1044S

V

+

1

2

3

4

8

7

6

5

TC1044S

C1

RL

C2

C1

"n"

"1"

+

Dos and Don'ts

• Do not exceed maximum supply voltages.

• Do not connect the LV terminal to GND for supply

voltages greater than 3.5V.

• Do not short circuit the output to V

+

 supply for voltages

above 5.5V for extended periods; however, transient
conditions including start-up are okay.

• When using polarized capacitors in the inverting mode,

the + terminal of C

1

 must be connected to pin 2 of the

TC1044S and the + terminal of C

2

 must be connected

to GND.

Simple Negative Voltage Converter

Figure 3 shows typical connections to provide a nega-

tive supply where a positive supply is available. A similar
scheme may be employed for supply voltages anywhere in
the operating range of +1.5V to +12V, keeping in mind that
pin 6 (LV) is tied to the supply negative (GND) only for supply
voltages below 3.5V.

1

2

3

4

8

7

6

5

TC1044S

10

µ

F

+

V

+

10

µ

F

+

VOUT

*

NOTES:

*

C1

C2

 

Figure 3.  Simple Negative Converter

R

OUT

 (of TC1044S)

n (number of devices)

R

OUT

 =

/var/www/html/datasheet/sites/default/files/pdfhtml_dummy/21348a-html.html
background image

5

TC1044S

Charge Pump DC-TO-DC Voltage Converter

TC1044S-12  9/16/96

© 2001 Microchip Technology Inc.     DS21348A

Figure 5.  Increased Output Voltage by Cascading Devices

situation where the designer has generated the external
clock frequency using TTL logic, the addition of a 10k

 pull-

up resistor to V

+

 supply is required. Note that the pump

frequency with external clocking, as with internal clocking,
will be 1/2 of the clock frequency. Output transitions occur on
the positive-going edge of the clock.

It is also possible to increase the conversion efficiency

of the TC1044S at low load levels by lowering the oscillator
frequency. This reduces the switching losses, and is achieved
by connecting an additional capacitor, C

OSC

, as shown in

Figure 7. Lowering the oscillator frequency will cause an
undesirable increase in the impedance of the pump (C

1

) and

the reservoir (C

2

) capacitors. To overcome this, increase the

values of C

1

 and C

2

 by the same factor that the frequency

has been reduced. For example, the addition of a 100pF
capacitor between pin 7 (OSC) and pin 8 (V

+

) will lower the

oscillator frequency to 1kHz from its nominal frequency of
10kHz (a multiple of 10), and necessitate a corresponding
increase in the values of C

1

 and C

2

 (from 10

µ

F to 100

µ

F).

Positive Voltage Multiplication

The TC1044S may be employed to achieve positive

voltage multiplication using the circuit shown in Figure 8. In
this application, the pump inverter switches of the TC1044S
are used to charge C

1

 to a voltage level of V

– V

F

 (where V

+

is the supply voltage and V

F

 is the forward voltage drop of

diode D

1

). On the transfer cycle, the voltage on C

1

 plus the

supply voltage (V

+

) is applied through diode D

2

 to capacitor

C

2

. The voltage thus created on C

2

 becomes (2V

+

) – (2V

F

),

or twice the supply voltage minus the combined forward
voltage drops of diodes D

1

 and D

2

.

The source impedance of the output (V

OUT

) will depend

on the output current, but for V

+

 = 5V and an output current

of 10mA, it will be approximately 60

.

Cascading Devices

The TC1044S may be cascaded as shown (Figure 5) to

produce larger negative multiplication of the initial supply
voltage. However, due to the finite efficiency of each device,
the practical limit is 10 devices for light loads. The output
voltage is defined by:

V

OUT

 = –n(V

IN

)

where n is an integer representing the number of devices
cascaded. The resulting output resistance would be ap-
proximately the weighted sum of the individual TC1044S
R

OUT

 values.

Changing the TC1044S Oscillator Frequency

It may be desirable in some applications (due to noise or

other considerations) to increase the oscillator frequency.
Pin 1, frequency boost pin may be connected to V

+

 to

increase oscillator frequency to 45kHz from a nominal of
10kHz for an input supply voltage of 5.0 volts. The oscillator
may also be synchronized to an external clock as shown in
Figure 6.   In order to prevent possible device latch-up, a 1k

resistor must be used in series with the clock output. In a

Figure 6.  External Clocking

1

2

3

4

8

7

6

5

TC1044S

+

V +

+

CMOS
GATE

10

µ

F

VOUT

10

µ

F

1k

V +

1

2

3

4

8

7

6

5

V

+

1

2

3

4

8

7

6

5

10

µ

F

10

µ

F

"n"

"1"

10

µ

F

VOUT

NOTES:

*

*

+

+

+

TC1044S

TC1044S

1. V

OUT

 = –n(V

+

) for 1.5V 

 V

+

 

 12V

10

µ

F

+

/var/www/html/datasheet/sites/default/files/pdfhtml_dummy/21348a-html.html
background image

TC1044S-12  9/16/96

TC1044S

Charge Pump DC-TO-DC Voltage Converter

6

© 2001 Microchip Technology Inc.     DS21348A

Figure 8.  Positive Voltage Multiplier

Combined Negative Voltage Conversion
and Positive Supply Multiplication

Figure 9 combines the functions shown in Figures 3 and

8 to provide negative voltage conversion and positive volt-
age multiplication simultaneously. This approach would be,
for example, suitable for generating +9V and –5V from an
existing +5V supply. In this instance, capacitors C

1

 and C

3

perform the pump and reservoir functions, respectively, for
the generation of the negative voltage, while capacitors C

2

and C

4

 are pump and reservoir, respectively, for the multi-

plied positive voltage. There is a penalty in this configuration
which combines both functions, however, in that the source
impedances of the generated supplies will be somewhat
higher due to the finite impedance of the common charge
pump driver at pin 2 of the device.

Efficient Positive Voltage
Multiplication/Conversion

Since the switches that allow the charge pumping op-

eration are bidirectional, the charge transfer can be per-
formed backwards as easily as forwards. Figure 10 shows
a TC1044S transforming –5V to +5V (or +5V to +10V, etc.).
The only problem here is that the internal clock and switch-
drive section will not operate until some positive voltage has
been generated. An initial inefficient pump, as shown in
Figure 9, could be used to start this circuit up, after which it

Figure 7.  Lowering Oscillator Frequency

1

2

3

4

8

7

6

5

+

V

+

VOUT

C1

COSC

+

C2

TC1044S

will bypass the other (D

1

 and D

2

 in Figure 9 would never turn

on), or else the diode and resistor shown dotted in Figure 10
can be used to "force" the internal regulator on.

Voltage Splitting

The same bidirectional characteristics used in Figure 10

can also be used to split a higher supply in half, as shown in
Figure 11. The combined load will be evenly shared be-
tween the two sides. Once again, a high value resistor to the
LV pin ensures start-up. Because the switches share the
load in parallel, the output impedance is much lower than in
the standard circuits, and higher currents can be drawn from
the device. By using this circuit, and then the circuit of Figure
5, +15V can be converted (via +7.5V and –7.5V) to a nominal
–15V, though with rather high series resistance (~250

).

1

2

3

4

8

7

6

5

V+

VOUT = 
(2 V+) – (2 VF)

+

C2

D1

D2

+

C1

TC1044S

1

2

3

4

8

7

6

5

+

V +

VOUT = 
(2 V +) – (2 VF)

C1

D1

+

+

C3

C4

VOUT = –V

+

C2

TC1044S

D2

+

Figure 9. Combined Negative Converter and Positive Multiplier

Negative Voltage Generation for
Display ADCs

The TC7106 is designed to work from a 9V battery. With

a fixed power supply system, the TC7106 will perform
conversions with input signal referenced to power supply
ground.

Negative Supply Generation for 4

¹⁄₂

 Digit

Data Acquisition System

The TC7135 is a 4

¹⁄₂

 digit ADC operating from 

±

5V

supplies. The TC1044S provides an inexpensive –5V source.
(See AN16 and AN17 for TC7135 interface details and
software routines.)

/var/www/html/datasheet/sites/default/files/pdfhtml_dummy/21348a-html.html
background image

7

TC1044S

Charge Pump DC-TO-DC Voltage Converter

TC1044S-12  9/16/96

© 2001 Microchip Technology Inc.     DS21348A

Figure 10.  Positive Voltage Conversion

1

2

3

4

8

7

6

5

+

VOUT = –V

10

µ

F

+

1 M

V– INPUT

C1

10

µ

F

TC1044S

Figure 11.  Splitting a Supply in Half

+

+

RL1

RL2

VOUT = 

V + –V –

2

50

µ

F

100

k

100

k

50

µ

F

V +

V –

50 

µ

F

+

1 M

1

2

8

7

TC1044S

3

4

6

5

TYPICAL CHARACTERISTICS

Unloaded Osc Freq vs. Temperature

12

10

0

2

4

6

8

-40

-20

0

20

40

100

60

80

OSCILLATOR FREQUENCY (kHz)

TEMPERATURE (

°

C)

V

IN

 = 12V

V

IN

 = 5V

Unloaded Osc Freq vs. Temperature

with Boost Pin = V

IN

60

50

0

10

20

30

40

-40

-20

0

20

40

100

60

80

OSCILLATOR FREQUENCY (kHz)

TEMPERATURE (

°

C)

V

IN

 = 12V

V

IN

 = 5V

Supply Current vs. Temperature

(with Boost Pin = V

IN

)

1000

0

200

400

600

800

-40

-20

0

20

40

100

60

80

I

DD

 (

µ

A)

TEMPERATURE (

°

C)

V

IN

 = 12V

Without Load

10K Load

Voltage Conversion

101.0

100.5

100.0

99.5

99.0

98.5

98.0

1

12

11

10

9

8

7

5

6

4

2

3

VOLTAGE CONVERSION EFFICIENCY (%)

INPUT VOLTAGE V

IN

 (V)

T

= 25

°

C

V

IN

 = 5V

/var/www/html/datasheet/sites/default/files/pdfhtml_dummy/21348a-html.html
background image

TC1044S-12  9/16/96

TC1044S

Charge Pump DC-TO-DC Voltage Converter

8

© 2001 Microchip Technology Inc.     DS21348A

TYPICAL CHARACTERISTICS (Cont.)

Output Voltage vs. Output Current

0

-2

-4

-6

-8

-10

-12

OUTPUT VOLTAGE V

OUT

 (V)

OUTPUT CURRENT (mA)

0

100

90

80

70

60

40

50

30

10

20

1.5

12

11.5

10.5

9.5

8.5

7.5

5.5 6.5

4.5

2.5 3.5

Output Source Resistance vs. Supply Voltage

100

10

30

50

70

OUTPUT SOURCE RESISTANCE (

)

SUPPLY VOLTAGE (V)

Output Source Resistance vs. Temperature

100

0

20

40

60

80

-40

-20

0

20

40

100

60

80

OUTPUT SOURCE RESISTANCE (

)

TEMPERATURE (

°

C)

V

IN

 = 2.5V

V

IN

 = 5.5V

Power Conversion Efficiency vs. Load

POWER EFFICIENCY (%)

LOAD CURRENT (mA)

Boost Pin = Open

Boost Pin = V+

0

10

20

30

40

50

60

70

80

90

100

60.0

55.0

50.0

40.0

35.0

30.0

25.0

20.0

15.0

10.0

9.0

7.5

6.0

4.5

3.0

2.0

1.5

1.0

I

OUT

 = 20mA

T

= 25

°

C

Supply Current vs. Temperature

200

150

125

175

100

75

50

25

0

SUPPLY CURRENT I

DD

 (

µ

A)

TEMPERATURE (

°

C)

-40

-20

0

20

40

100

60

80

V

IN

 = 12.5V

V

IN

 = 5.5V

/var/www/html/datasheet/sites/default/files/pdfhtml_dummy/21348a-html.html
background image

9

TC1044S

Charge Pump DC-TO-DC Voltage Converter

TC1044S-12  9/16/96

© 2001 Microchip Technology Inc.     DS21348A

PACKAGE DIMENSIONS

Dimensions:  inches (mm)

8-Pin Plastic DIP

3

°

 MIN.

PIN 1

.260 (6.60)
.240 (6.10)

.045 (1.14)
.030 (0.76)

.070 (1.78)
.040 (1.02)

.400 (10.16)

.348 (8.84)

.200 (5.08)
.140 (3.56)

.150 (3.81)
.115 (2.92)

.110 (2.79)
.090 (2.29)

.022 (0.56)
.015 (0.38)

.040 (1.02)
.020 (0.51)

.015 (0.38)
.008 (0.20)

.310 (7.87)
.290 (7.37)

.400 (10.16)

.310 (7.87)

.400 (10.16)

.370 (9.40)

.300 (7.62)
.230 (5.84)

.065 (1.65)
.045 (1.14)

.055 (1.40) MAX.

.020 (0.51) MIN.

PIN 1

.200 (5.08)
.160 (4.06)

.200 (5.08)
.125 (3.18)

.110 (2.79)
.090 (2.29)

.020 (0.51)
.016 (0.41)

.040 (1.02)
.020 (0.51)

.320 (8.13)
.290 (7.37)

.150 (3.81) 

MIN.

3

°

 MIN.

.015 (0.38)
.008 (0.20)

.400 (10.16)

.320 (8.13)

8-Pin CerDIP

/var/www/html/datasheet/sites/default/files/pdfhtml_dummy/21348a-html.html
background image

TC1044S-12  9/16/96

TC1044S

Charge Pump DC-TO-DC Voltage Converter

10

© 2001 Microchip Technology Inc.     DS21348A

8-Pin SOIC

.050 (1.27) TYP.

8

°

 MAX.

.244 (6.20)
.228 (5.79)

.157 (3.99)
.150 (3.81)

.197 (5.00)
.189 (4.80)

.020 (0.51)
.013 (0.33)

.010 (0.25)
.004 (0.10)

.069 (1.75)
.053 (1.35)

.010 (0.25)
.007 (0.18)

.050 (1.27)
.016 (0.40)

PACKAGE DIMENSIONS (CONT.)

Dimensions:  inches (mm)

/var/www/html/datasheet/sites/default/files/pdfhtml_dummy/21348a-html.html
background image

TC1044S

TC1044S-12  9/16/96

EVALUATION

KIT

AVAILABLE

© 2001 Microchip Technology Inc.     DS21348A

Charge Pump DC-TO-DC Voltage Converter

FEATURES

Converts +5V Logic Supply to 

±

5V System

Wide Input Voltage Range .................... 1.5V to 12V

Efficient Voltage Conversion ......................... 99.9%

Excellent Power Efficiency ............................... 98%

Low Power Consumption ............ 80

µ

A @ V

IN

 = 5V

Low Cost and Easy to Use
— Only Two External Capacitors Required

RS-232 Negative Power Supply

Available in 8-Pin Small Outline (SOIC) and 8-Pin
Plastic DIP Packages

Improved ESD Protection ..................... Up to 10kV

No External Diode Required for High Voltage
Operation

Frequency Boost Raises F

OSC

 to 45kHz

GENERAL DESCRIPTION

The TC1044S is a pin-compatible upgrade to the Indus-

try standard TC7660 charge pump voltage converter. It
converts a +1.5V to +12V input to a corresponding –1.5V
to –12V output using only two low cost capacitors, eliminat-
ing inductors and their associated cost, size and EMI.
Added features include an extended supply range to 12V,
and a frequency boost pin for higher operating frequency,
allowing the use of smaller external capacitors.

The on-board oscillator operates at a nominal frequency

of 10kHz. Frequency is increased to 45kHz when pin 1 is
connected to V

+

.  Operation below 10kHz (for lower supply

current applications) is possible by connecting an external
capacitor from OSC to ground (with pin 1 open).

The TC1044S is available in both 8-pin DIP and

8-pin small outline (SOIC) packages in commercial and
extended temperature ranges.

FUNCTIONAL BLOCK DIAGRAM

TC1044S

GND

INTERNAL

VOLTAGE

REGULATOR

RC

OSCILLATOR

VOLTAGE–

LEVEL

TRANSLATOR

2

V +

CAP +

8

2

7

6

OSC

LV

3

LOGIC

NETWORK

VOUT

5

CAP –

4

1

BOOST

ORDERING INFORMATION

Part No.

Package

 Temp. Range

TC1044SCOA

8-Pin SOIC

0

°

C to +70

°

C

TC1044SCPA

8-Pin Plastic DIP

0

°

C to +70

°

C

TC1044SEOA

8-Pin SOIC

– 40

°

C to +85

°

C

TC1044SEPA

8-Pin Plastic DIP

– 40

°

C to +85

°

C

TC1044SIJA

8-Pin CerDIP

– 25

°

C to +85

°

C

TC1044SMJA

8-Pin CerDIP

– 55

°

C to +125

°

C

TC7660EV

Charge Pump Family Evaluation Kit

PIN CONFIGURATION (DIP AND SOIC)

1

2

3

4

8

7

6

5

TC1044SCPA
TC1044SEPA

TC1044SIJA

TC1044SMJA

BOOST

CAP +

GND

CAP –

VOUT

LOW
VOLTAGE (LV)

OSC

+

V

1

2

3

4

8

7

6

5

TC1044SCOA

TC1044SEOA

BOOST

CAP +

GND

CAP –

VOUT

LOW
VOLTAGE (LV)

OSC

+

V

/var/www/html/datasheet/sites/default/files/pdfhtml_dummy/21348a-html.html
background image

TC1044S-12  9/16/96

TC1044S

Charge Pump DC-TO-DC Voltage Converter

2

© 2001 Microchip Technology Inc.     DS21348A

Package Power Dissipation (T

A

 

 70

°

C) (Note 2)

8-Pin CerDIP .................................................. 800mW
8-Pin Plastic DIP ............................................. 730mW
8-Pin SOIC ..................................................... 470mW

Operating Temperature Range

C Suffix .................................................. 0

°

C to +70

°

C

I Suffix ............................................... – 25

°

C to +85

°

C

E Suffix ............................................. – 40

°

C to +85

°

C

M Suffix ........................................... – 55

°

C to +125

°

C

Storage Temperature Range ................ – 65

°

C to +150

°

C

ELECTRICAL CHARACTERISTICS:

T

A

 = +25

°

C, V

+

 = 5V, C

OSC

 = 0, Test Circuit (Figure 1), unless otherwise

indicated.

Symbol

Parameter

Test Conditions

Min

Typ

Max

Unit

I

+

Supply Current

R

L

 = 

80

160

µ

A

0

°

C < T

A

 < +70

°

C

180

– 40

°

C < T

A

 < +85

°

C

180

– 55

°

C < T

A

 < +125

°

C

200

I

+

Supply Current

0

°

C < T

A

 < +70

°

C

300

µ

A

(Boost Pin = V

+

)

–  40

°

C < T

A

 < +85

°

C

350

– 55

°

C < T

A

 < +125

°

C

400

V

+

H2

Supply Voltage Range, High

Min 

 T

A

 

 Max,

3

12

V

R

L

 = 10 k

, LV Open

V

+

L2

Supply Voltage Range, Low

Min 

 T

A

 

 Max,

1.5

3.5

V

R

L

 = 10 k

, LV to GND

R

OUT

Output Source Resistance

I

OUT

 = 20mA

60

100

I

OUT

 = 20mA, 0

°

 T

A

 

 +70

°

C

70

120

I

OUT

 = 20mA, –40

°

 T

A

 

 +85

°

C

70

120

I

OUT

 = 20mA, –55

°

 T

A

 

 +125

°

C

105

150

V

+

 = 2V, I

OUT

 = 3 mA, LV to GND

0

°

 T

A

 

 +70

°

C

250

– 55

°

 T

A

 

 +125

°

C

400

F

OSC

Oscillator Frequency

Pin 7 open; Pin 1 open or GND

10

kHz

Boost Pin = V

+

45

P

EFF

Power Efficiency

R

L

 = 5 k

; Boost Pin Open

96

98

%

T

MIN

 < T

A

 < T

MAX

; Boost Pin Open

95

97

Boost Pin = V

+

88

V

OUT 

E

FF

Voltage Conversion Efficiency

R

L

 = 

99

99.9

%

Z

OSC

Oscillator Impedance

V

+

 = 2V

1

M

V

+

 = 5V

100

k

NOTES: 1. Connecting any input terminal to voltages greater than V

+

 or less than GND may cause destructive latch-up. It is recommended that no

inputs from sources operating from external supplies be applied prior to "power up" of the TC1044S.

2. Derate linearly above 50

°

C by 5.5mW/

°

C.

ABSOLUTE MAXIMUM RATINGS*

Supply Voltage ......................................................... +13V
LV, Boost and OSC Inputs

Voltage (Note 1) ......................... – 0.3V to (V

+

+ 0.3V)

for V

+

 < 5.5V

(V

– 5.5V) to (V

+

+ 0.3V)

for V

+

 > 5.5V

Current Into LV (Note 1) ...................... 20

µ

A for V

+

 > 3.5V

Output Short Duration (V

SUPPLY

 

 5.5V) ......... Continuous

Lead Temperature (Soldering, 10 sec) ................. +300

°

C

*Static-sensitive device. Unused devices must be stored in conductive material. Protect devices from static discharge and static fields. Stresses above those
listed under "Absolute Maximum Ratings" may cause permanent damage to the device. These are stress ratings only and functional operation of the device
at these or any other conditions above those indicated in the operation sections of the specifications is not implied.  Exposure to absolute maximum rating
conditions for extended periods may affect device reliability.

/var/www/html/datasheet/sites/default/files/pdfhtml_dummy/21348a-html.html
background image

3

TC1044S

Charge Pump DC-TO-DC Voltage Converter

TC1044S-12  9/16/96

© 2001 Microchip Technology Inc.     DS21348A

Circuit Description

The TC1044S contains all the necessary circuitry to

implement a voltage inverter, with the exception of two
external capacitors, which may be inexpensive 10 

µ

F polar-

ized electrolytic capacitors. Operation is best understood by
considering Figure 2, which shows an idealized voltage
inverter. Capacitor C

1

 is charged to a voltage, V

+

, for the half

cycle when switches S

1

 and S

3

 are closed. (Note: Switches

S

2

 and S

4

 are open during this half cycle.) During the second

half cycle of operation, switches S

2

 and S

4

 are closed, with

S

1

 and S

3

 open, thereby shifting capacitor C

1

 negatively by

V

+

 volts. Charge is then transferred from C

1

 to C

2

, such that

the voltage on C

2

 is exactly V

+

, assuming ideal switches and

no load on C

2

.

The four switches in Figure 2 are MOS power switches;

S

1

 is a P-channel device, and S

2

, S

3

 and S

4

 are N-channel

devices. The main difficulty with this approach is that in
integrating the switches, the substrates of S

3

 and S

4

 must

always remain reverse-biased with respect to their sources,
but not so much as to degrade their ON resistances. In
addition, at circuit start-up, and under output short circuit
conditions (V

OUT

 = V

+

), the output voltage must be sensed

and the substrate bias adjusted accordingly. Failure to
accomplish this will result in high power losses and probable
device latch-up.

This problem is eliminated in the TC1044S by a logic

network which senses the output voltage (V

OUT

) together

with the level translators, and switches the substrates of
S

3

 and S

4

 to the correct level to maintain necessary reverse

bias.

Figure 2.  Idealized Charge Pump Inverter

V+

GND

S3

S1

S2

S4

C2

VOUT = – VIN

C1

The voltage regulator portion of the TC1044S is an

integral part of the anti-latch-up circuitry. Its inherent voltage
drop can, however, degrade operation at low voltages. To
improve low-voltage operation, the “LV” pin should be
connected to GND, disabling the regulator. For supply
voltages greater than 3.5V, the LV terminal must be left
open to ensure latch-up-proof operation and prevent device
damage.

Theoretical Power Efficiency
Considerations

In theory, a capacitive charge pump can approach

100% efficiency if certain conditions are met:

(1) The drive circuitry consumes minimal power.

(2) The output switches have extremely low ON

resistance and virtually no offset.

(3) The impedances of the pump and reservoir

capacitors are negligible at the pump frequency.

The TC1044S approaches these conditions for nega-

tive voltage multiplication if large values of C

1

 and C

2

 are

used.  Energy is lost only in the transfer of charge
between capacitors if a change in voltage occurs. 
The
energy lost is defined by:

E = 1/2 C

1

 (V

1

2

 – V

2

2

)

V

1

 and V

2

 are the voltages on C

1

 during the pump and

transfer cycles. If the impedances of C

1

 and C

2

 are relatively

high at the pump frequency (refer to Figure 2) compared to
the value of R

L

, there will be a substantial difference in

voltages V

1

 and V

2

. Therefore, it is desirable not only to

make C

2

 as large as possible to eliminate output voltage

ripple, but also to employ a correspondingly large value for
C

1

 in order to achieve maximum efficiency of operation.

1

2

3

4

8

7

6

5

TC1044S

+

V+

(+5V)

VOUT

C1

1

µ

F

COSC

*

+

C2

10

µ

F

IL

RL

IS

V+

NOTE:   For large values of C

OSC

 (>1000pF), the values 

of C

1

 and C

2

 should be increased to 100

µ

F.

Figure 1.  TC1044S Test Circuit

/var/www/html/datasheet/sites/default/files/pdfhtml_dummy/21348a-html.html
background image

TC1044S-12  9/16/96

TC1044S

Charge Pump DC-TO-DC Voltage Converter

4

© 2001 Microchip Technology Inc.     DS21348A

The output characteristics of the circuit in Figure 3 are

those of a nearly ideal voltage source in series with 70

.

Thus, for a load current of –10mA and a supply voltage of
+5V, the output voltage would be – 4.3V.

The dynamic output impedance of the TC1044S is due,

primarily, to capacitive reactance of the charge transfer
capacitor (C

1

). Since this capacitor is connected to the

output for only 1/2 of the cycle, the equation is:

Paralleling Devices

Any number of TC1044S voltage converters may be

paralleled to reduce output resistance (Figure 4). The reser-
voir capacitor, C

2

, serves all devices, while each device

requires its own pump capacitor, C

1

. The resultant output

resistance would be approximately:

2

2

π

f

 

C

1

    X

=               = 3.18

Ω,

where f = 10 kHz and C

= 10

µ

F.

Figure 4.  Paralleling Devices Lowers Output Impedance

1

2

3

4

8

7

6

5

TC1044S

V

+

1

2

3

4

8

7

6

5

TC1044S

C1

RL

C2

C1

"n"

"1"

+

Dos and Don'ts

• Do not exceed maximum supply voltages.

• Do not connect the LV terminal to GND for supply

voltages greater than 3.5V.

• Do not short circuit the output to V

+

 supply for voltages

above 5.5V for extended periods; however, transient
conditions including start-up are okay.

• When using polarized capacitors in the inverting mode,

the + terminal of C

1

 must be connected to pin 2 of the

TC1044S and the + terminal of C

2

 must be connected

to GND.

Simple Negative Voltage Converter

Figure 3 shows typical connections to provide a nega-

tive supply where a positive supply is available. A similar
scheme may be employed for supply voltages anywhere in
the operating range of +1.5V to +12V, keeping in mind that
pin 6 (LV) is tied to the supply negative (GND) only for supply
voltages below 3.5V.

1

2

3

4

8

7

6

5

TC1044S

10

µ

F

+

V

+

10

µ

F

+

VOUT

*

NOTES:

*

C1

C2

 

Figure 3.  Simple Negative Converter

R

OUT

 (of TC1044S)

n (number of devices)

R

OUT

 =

/var/www/html/datasheet/sites/default/files/pdfhtml_dummy/21348a-html.html
background image

5

TC1044S

Charge Pump DC-TO-DC Voltage Converter

TC1044S-12  9/16/96

© 2001 Microchip Technology Inc.     DS21348A

Figure 5.  Increased Output Voltage by Cascading Devices

situation where the designer has generated the external
clock frequency using TTL logic, the addition of a 10k

 pull-

up resistor to V

+

 supply is required. Note that the pump

frequency with external clocking, as with internal clocking,
will be 1/2 of the clock frequency. Output transitions occur on
the positive-going edge of the clock.

It is also possible to increase the conversion efficiency

of the TC1044S at low load levels by lowering the oscillator
frequency. This reduces the switching losses, and is achieved
by connecting an additional capacitor, C

OSC

, as shown in

Figure 7. Lowering the oscillator frequency will cause an
undesirable increase in the impedance of the pump (C

1

) and

the reservoir (C

2

) capacitors. To overcome this, increase the

values of C

1

 and C

2

 by the same factor that the frequency

has been reduced. For example, the addition of a 100pF
capacitor between pin 7 (OSC) and pin 8 (V

+

) will lower the

oscillator frequency to 1kHz from its nominal frequency of
10kHz (a multiple of 10), and necessitate a corresponding
increase in the values of C

1

 and C

2

 (from 10

µ

F to 100

µ

F).

Positive Voltage Multiplication

The TC1044S may be employed to achieve positive

voltage multiplication using the circuit shown in Figure 8. In
this application, the pump inverter switches of the TC1044S
are used to charge C

1

 to a voltage level of V

– V

F

 (where V

+

is the supply voltage and V

F

 is the forward voltage drop of

diode D

1

). On the transfer cycle, the voltage on C

1

 plus the

supply voltage (V

+

) is applied through diode D

2

 to capacitor

C

2

. The voltage thus created on C

2

 becomes (2V

+

) – (2V

F

),

or twice the supply voltage minus the combined forward
voltage drops of diodes D

1

 and D

2

.

The source impedance of the output (V

OUT

) will depend

on the output current, but for V

+

 = 5V and an output current

of 10mA, it will be approximately 60

.

Cascading Devices

The TC1044S may be cascaded as shown (Figure 5) to

produce larger negative multiplication of the initial supply
voltage. However, due to the finite efficiency of each device,
the practical limit is 10 devices for light loads. The output
voltage is defined by:

V

OUT

 = –n(V

IN

)

where n is an integer representing the number of devices
cascaded. The resulting output resistance would be ap-
proximately the weighted sum of the individual TC1044S
R

OUT

 values.

Changing the TC1044S Oscillator Frequency

It may be desirable in some applications (due to noise or

other considerations) to increase the oscillator frequency.
Pin 1, frequency boost pin may be connected to V

+

 to

increase oscillator frequency to 45kHz from a nominal of
10kHz for an input supply voltage of 5.0 volts. The oscillator
may also be synchronized to an external clock as shown in
Figure 6.   In order to prevent possible device latch-up, a 1k

resistor must be used in series with the clock output. In a

Figure 6.  External Clocking

1

2

3

4

8

7

6

5

TC1044S

+

V +

+

CMOS
GATE

10

µ

F

VOUT

10

µ

F

1k

V +

1

2

3

4

8

7

6

5

V

+

1

2

3

4

8

7

6

5

10

µ

F

10

µ

F

"n"

"1"

10

µ

F

VOUT

NOTES:

*

*

+

+

+

TC1044S

TC1044S

1. V

OUT

 = –n(V

+

) for 1.5V 

 V

+

 

 12V

10

µ

F

+

/var/www/html/datasheet/sites/default/files/pdfhtml_dummy/21348a-html.html
background image

TC1044S-12  9/16/96

TC1044S

Charge Pump DC-TO-DC Voltage Converter

6

© 2001 Microchip Technology Inc.     DS21348A

Figure 8.  Positive Voltage Multiplier

Combined Negative Voltage Conversion
and Positive Supply Multiplication

Figure 9 combines the functions shown in Figures 3 and

8 to provide negative voltage conversion and positive volt-
age multiplication simultaneously. This approach would be,
for example, suitable for generating +9V and –5V from an
existing +5V supply. In this instance, capacitors C

1

 and C

3

perform the pump and reservoir functions, respectively, for
the generation of the negative voltage, while capacitors C

2

and C

4

 are pump and reservoir, respectively, for the multi-

plied positive voltage. There is a penalty in this configuration
which combines both functions, however, in that the source
impedances of the generated supplies will be somewhat
higher due to the finite impedance of the common charge
pump driver at pin 2 of the device.

Efficient Positive Voltage
Multiplication/Conversion

Since the switches that allow the charge pumping op-

eration are bidirectional, the charge transfer can be per-
formed backwards as easily as forwards. Figure 10 shows
a TC1044S transforming –5V to +5V (or +5V to +10V, etc.).
The only problem here is that the internal clock and switch-
drive section will not operate until some positive voltage has
been generated. An initial inefficient pump, as shown in
Figure 9, could be used to start this circuit up, after which it

Figure 7.  Lowering Oscillator Frequency

1

2

3

4

8

7

6

5

+

V

+

VOUT

C1

COSC

+

C2

TC1044S

will bypass the other (D

1

 and D

2

 in Figure 9 would never turn

on), or else the diode and resistor shown dotted in Figure 10
can be used to "force" the internal regulator on.

Voltage Splitting

The same bidirectional characteristics used in Figure 10

can also be used to split a higher supply in half, as shown in
Figure 11. The combined load will be evenly shared be-
tween the two sides. Once again, a high value resistor to the
LV pin ensures start-up. Because the switches share the
load in parallel, the output impedance is much lower than in
the standard circuits, and higher currents can be drawn from
the device. By using this circuit, and then the circuit of Figure
5, +15V can be converted (via +7.5V and –7.5V) to a nominal
–15V, though with rather high series resistance (~250

).

1

2

3

4

8

7

6

5

V+

VOUT = 
(2 V+) – (2 VF)

+

C2

D1

D2

+

C1

TC1044S

1

2

3

4

8

7

6

5

+

V +

VOUT = 
(2 V +) – (2 VF)

C1

D1

+

+

C3

C4

VOUT = –V

+

C2

TC1044S

D2

+

Figure 9. Combined Negative Converter and Positive Multiplier

Negative Voltage Generation for
Display ADCs

The TC7106 is designed to work from a 9V battery. With

a fixed power supply system, the TC7106 will perform
conversions with input signal referenced to power supply
ground.

Negative Supply Generation for 4

¹⁄₂

 Digit

Data Acquisition System

The TC7135 is a 4

¹⁄₂

 digit ADC operating from 

±

5V

supplies. The TC1044S provides an inexpensive –5V source.
(See AN16 and AN17 for TC7135 interface details and
software routines.)

/var/www/html/datasheet/sites/default/files/pdfhtml_dummy/21348a-html.html
background image

7

TC1044S

Charge Pump DC-TO-DC Voltage Converter

TC1044S-12  9/16/96

© 2001 Microchip Technology Inc.     DS21348A

Figure 10.  Positive Voltage Conversion

1

2

3

4

8

7

6

5

+

VOUT = –V

10

µ

F

+

1 M

V– INPUT

C1

10

µ

F

TC1044S

Figure 11.  Splitting a Supply in Half

+

+

RL1

RL2

VOUT = 

V + –V –

2

50

µ

F

100

k

100

k

50

µ

F

V +

V –

50 

µ

F

+

1 M

1

2

8

7

TC1044S

3

4

6

5

TYPICAL CHARACTERISTICS

Unloaded Osc Freq vs. Temperature

12

10

0

2

4

6

8

-40

-20

0

20

40

100

60

80

OSCILLATOR FREQUENCY (kHz)

TEMPERATURE (

°

C)

V

IN

 = 12V

V

IN

 = 5V

Unloaded Osc Freq vs. Temperature

with Boost Pin = V

IN

60

50

0

10

20

30

40

-40

-20

0

20

40

100

60

80

OSCILLATOR FREQUENCY (kHz)

TEMPERATURE (

°

C)

V

IN

 = 12V

V

IN

 = 5V

Supply Current vs. Temperature

(with Boost Pin = V

IN

)

1000

0

200

400

600

800

-40

-20

0

20

40

100

60

80

I

DD

 (

µ

A)

TEMPERATURE (

°

C)

V

IN

 = 12V

Without Load

10K Load

Voltage Conversion

101.0

100.5

100.0

99.5

99.0

98.5

98.0

1

12

11

10

9

8

7

5

6

4

2

3

VOLTAGE CONVERSION EFFICIENCY (%)

INPUT VOLTAGE V

IN

 (V)

T

= 25

°

C

V

IN

 = 5V

/var/www/html/datasheet/sites/default/files/pdfhtml_dummy/21348a-html.html
background image

TC1044S-12  9/16/96

TC1044S

Charge Pump DC-TO-DC Voltage Converter

8

© 2001 Microchip Technology Inc.     DS21348A

TYPICAL CHARACTERISTICS (Cont.)

Output Voltage vs. Output Current

0

-2

-4

-6

-8

-10

-12

OUTPUT VOLTAGE V

OUT

 (V)

OUTPUT CURRENT (mA)

0

100

90

80

70

60

40

50

30

10

20

1.5

12

11.5

10.5

9.5

8.5

7.5

5.5 6.5

4.5

2.5 3.5

Output Source Resistance vs. Supply Voltage

100

10

30

50

70

OUTPUT SOURCE RESISTANCE (

)

SUPPLY VOLTAGE (V)

Output Source Resistance vs. Temperature

100

0

20

40

60

80

-40

-20

0

20

40

100

60

80

OUTPUT SOURCE RESISTANCE (

)

TEMPERATURE (

°

C)

V

IN

 = 2.5V

V

IN

 = 5.5V

Power Conversion Efficiency vs. Load

POWER EFFICIENCY (%)

LOAD CURRENT (mA)

Boost Pin = Open

Boost Pin = V+

0

10

20

30

40

50

60

70

80

90

100

60.0

55.0

50.0

40.0

35.0

30.0

25.0

20.0

15.0

10.0

9.0

7.5

6.0

4.5

3.0

2.0

1.5

1.0

I

OUT

 = 20mA

T

= 25

°

C

Supply Current vs. Temperature

200

150

125

175

100

75

50

25

0

SUPPLY CURRENT I

DD

 (

µ

A)

TEMPERATURE (

°

C)

-40

-20

0

20

40

100

60

80

V

IN

 = 12.5V

V

IN

 = 5.5V

/var/www/html/datasheet/sites/default/files/pdfhtml_dummy/21348a-html.html
background image

9

TC1044S

Charge Pump DC-TO-DC Voltage Converter

TC1044S-12  9/16/96

© 2001 Microchip Technology Inc.     DS21348A

PACKAGE DIMENSIONS

Dimensions:  inches (mm)

8-Pin Plastic DIP

3

°

 MIN.

PIN 1

.260 (6.60)
.240 (6.10)

.045 (1.14)
.030 (0.76)

.070 (1.78)
.040 (1.02)

.400 (10.16)

.348 (8.84)

.200 (5.08)
.140 (3.56)

.150 (3.81)
.115 (2.92)

.110 (2.79)
.090 (2.29)

.022 (0.56)
.015 (0.38)

.040 (1.02)
.020 (0.51)

.015 (0.38)
.008 (0.20)

.310 (7.87)
.290 (7.37)

.400 (10.16)

.310 (7.87)

.400 (10.16)

.370 (9.40)

.300 (7.62)
.230 (5.84)

.065 (1.65)
.045 (1.14)

.055 (1.40) MAX.

.020 (0.51) MIN.

PIN 1

.200 (5.08)
.160 (4.06)

.200 (5.08)
.125 (3.18)

.110 (2.79)
.090 (2.29)

.020 (0.51)
.016 (0.41)

.040 (1.02)
.020 (0.51)

.320 (8.13)
.290 (7.37)

.150 (3.81) 

MIN.

3

°

 MIN.

.015 (0.38)
.008 (0.20)

.400 (10.16)

.320 (8.13)

8-Pin CerDIP

/var/www/html/datasheet/sites/default/files/pdfhtml_dummy/21348a-html.html
background image

TC1044S-12  9/16/96

TC1044S

Charge Pump DC-TO-DC Voltage Converter

10

© 2001 Microchip Technology Inc.     DS21348A

8-Pin SOIC

.050 (1.27) TYP.

8

°

 MAX.

.244 (6.20)
.228 (5.79)

.157 (3.99)
.150 (3.81)

.197 (5.00)
.189 (4.80)

.020 (0.51)
.013 (0.33)

.010 (0.25)
.004 (0.10)

.069 (1.75)
.053 (1.35)

.010 (0.25)
.007 (0.18)

.050 (1.27)
.016 (0.40)

PACKAGE DIMENSIONS (CONT.)

Dimensions:  inches (mm)

Maker
Microchip Technology Inc.
Datasheet PDF Download