21385D.book

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 2001-2012 Microchip Technology Inc.

DS21385D-page 1

Features

• LDO with Integrated Microcontroller Reset 

Monitor Functionality

• Low Input Supply Current (80 µA, typical)

• Very Low Dropout Voltage

• 10 µsec (typ.) Wake-Up Time from SHDN

• 300 mA Output Current

• Standard or Custom Output and Detected 

Voltages

• Power-Saving Shutdown Mode

• Bypass Input for Quiet Operation

• Separate Input for Detected Voltage 

• 140 msec Minimum RESET Output Duration

• Space-Saving MSOP Package

• Specified Junction Temperature Range:

-40°C to +125°C

Applications

• Battery-Operated Systems

• Portable Computers

• Medical Instruments

• Pagers

• Cellular / GSM / PHS Phones

Related Literature

• AN765, “Using Microchip’s Micropower LDOs”, 

DS00765.

• AN766, “Pin-Compatible CMOS Upgrades to 

Bipolar LDOs”, DS00766.

• AN792, “A Method to Determine How Much 

Power a SOT23 Can Dissipate in an Application”, 
DS00792.

Package Type

General Description

The TC1300 combines a low dropout regulator and a
microcontroller reset monitor in an 8-Pin MSOP pack-
age. Total supply current is 80 µA (typical), 20 to 60
times lower than bipolar regulators.

The TC1300 has a precise output with a typical accu-
racy of ±0.5%. Other key features include low noise
operation, low dropout voltage and internal feed-
forward compensation for fast response to step
changes in load. The TC1300 has both over-tempera-
ture and over-current protection. When the shutdown
control (SHDN) is low, the regulator output voltage falls
to zero, RESET output remains valid and supply cur-
rent is reduced to 30 µA (typical). The TC1300 is rated
for 300 mA of output current and stable with a 1 µF out-
put capacitor.

An active-low RESET is asserted when the detected
voltage (V

DET

) falls below the reset voltage threshold.

The RESET output remains low for 300 msec (typical)
after V

DET

 rises above reset threshold. The TC1300

also has a fast wake-up response time (10 µsec.,
typical) when released from shutdown.

Typical Application Circuit

1

2

3

4

V

IN

V

DET

5

6

7

8

NC

V

OUT

GND

Bypass

SHDN

RESET

TC1300VUA

MSOP

TC1300

1

2

3

4

5

6

7

8

V

OUT

C

BYPASS

470 pF
(Optional)

Shutdown Control
(from Power 
Control Logic)

GND

Bypass

V

IN

SHDN

V

OUT

C

1

1 µF

RESET

RESET

V

DET

NC

C

2

1 µF

Battery

V

DET

+

TC1300

300 mA CMOS LDO with Shutdown, Bypass and 

Independent Delayed Reset Function

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TC1300

DS21385D-page 2

 2001-2012 Microchip Technology Inc.

1.0

ELECTRICAL 
CHARACTERISTICS

Absolute Maximum Ratings*

Input Voltage ....................................................................6.5V

Output Voltage ................................. (V

SS

 - 0.3) to (V

IN

 + 0.3)

Power Dissipation ......................... Internally Limited (Note 6)

Operating Junction Temperature, T

J

....... – 40°C < T

J

< 150°C

Maximum Junction Temperature, Tj .............................. 150°C
Storage Temperature................................... – 65°C to +150°C
Maximum Voltage on Any Pin  ............. (V

SS

-0.3) to (V

IN

+0.3)

*Notice: Stresses above those listed under “maximum rat-
ings” may cause permanent damage to the device. This is a
stress rating only and functional operation of the device at
those or any other conditions above those indicated in the
operational listings of this specification is not implied. Expo-
sure to maximum rating conditions for extended periods may
affect device reliability.

PIN DESCRIPTIONS

Pin

Description

RESET

RESET output remains low while V

DET

 is 

below the reset voltage threshold and for 
300 msec after V

DET

 rises above reset thesh-

old.

V

OUT

Regulated Voltage Output

GND

Ground Terminal

Bypass

Reference Bypass Input. Connecting an 
optional 470 pF to this input further reduces 
output noise.

SHDN

Shutdown Control Input. The regulator is fully 
enabled when a logic high is applied to this 
input. The regulator enters shutdown when a 
logic low is applied to this input. During shut-
down, regulator output voltage falls to zero, 
RESET output remains valid and supply cur-
rent is reduced to 30 µA (typ.).

NC

No connect

V

IN

Power Supply Input

V

DET

Detected Input Voltage. V

DET

 and V

IN 

can be 

connected together.

ELECTRICAL CHARACTERISTICS

V

IN

 = V

OUT

 + 1V, I

L

 = 0.1 mA, C

L

 = 3.3 µF, SHDN > V

IH

, T

A

 = 25°C, unless otherwise noted. BOLDFACE type specifications apply 

for junction temperature (Note 8) of -40°C to +125°C.

Parameters

Sym

Min

Typ

Max

Units

Conditions

Input Operating Voltage

V

IN

2.7

6.0

V

Note 7

Maximum Output Current

I

OUTMAX

300

mA

Output Voltage

V

OUT

V

R

 - 2.5%

V

R

  ± 0.5%

V

R

 + 2.5%

V

Note 1

V

OUT

 Temperature Coefficient

V

OUT

/

T

25

ppm/°C Note 2

Line Regulation

V

OUT

/

V

IN

0.02

0.35

%

(V

R

 + 1V) < V

IN

 < 6V

Load Regulation

V

OUT

/V

OUT

0.5

2.0

%

I

L

 = 0.1 mA to I

OUT

MAX, 

Note 3

Note

1: V

R

 is the regulator output voltage setting.

2:

3: Regulation is measured at a constant junction temperature using low duty cycle pulse testing. Load regulation is tested 

over a load range from 0.1 mA to the maximum specified output current. Changes in output voltage due to heating 
effects are covered by the thermal regulation specification.

4: Dropout voltage is defined as the input to output differential at which the output voltage drops 2% below its nominal value 

measured at a 1V differential.

5: Thermal Regulation is defined as the change in output voltage at a time t after a change in power dissipation is applied, 

excluding load or line regulation effects. Specifications are for a current pulse equal to I

LMAX

 at V

IN

 = 6V for t = 10 msec.

6: The maximum allowable power dissipation is a function of ambient temperature, the maximum allowable junction tem-

perature and the thermal resistance from junction-to-air (i.e. T

A

, T

J

JA

). Exceeding the maximum allowable power dissi-

pation causes the device to initiate thermal shutdown. Please see Section 4.0, “Thermal Considerations”, of this data 
sheet for more details.

7: The minimum V

IN

 has to meet two conditions: V

IN

 

 2.7V and V

IN

 

 (V

R

 + V

DROPOUT

).

8: The junction temperature of the device is approximated by soaking the device under test at an ambient temperature 

equal to the desired junction temperature. The test time is small enough such that the rise in the junction temperature 
over the ambient temperature is not significant.

TCV

OUT

V

OUTMAX

V

OUTMIN

 10

6

V

OUT

T

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DS21385D-page 3

TC1300

Dropout Voltage (Note 4)

V

IN –

V

OUT

1

70

210

30

130
390

mV

I

L

 = 0.1 mA

I

L

 = 100 mA

I

L

 = 300 mA

Supply Current

I

SS1

80

160

µA

SHDN = V

IH

Shutdown Supply Current

I

SS2

30

60

µA

SHDN = 0V

Power Supply Rejection Ratio

PSRR

60

dB

 1 kHz, C

BYPASS

 = 1 nF

Output Short Circuit Current

I

OUTSC

800

1200

mA

V

OUT

 = 0V

Thermal Regulation

V

OUT

/

P

D

— 0.04

— 

%/W

Note 5

Output Noise

eN

900

nV/Hz

f < 1 kHz, C

OUT

 = 1 µF,

R

LOAD

 = 50



C

BYPASS

 = 1 nF

Wake-Up Time
(from Shutdown Mode)

t

WK

10

20

µsec

C

IN

 = 1 µF, V

IN

 = 5V,

C

OUT

 = 4.7 µF, I

L

 = 30 mA,

See Figure 3-2

Settling Time
(from Shutdown Mode)

ts

50

µsec

C

IN

 = 1 µF, V

IN

 = 5V

C

OUT

 = 4.7 µF

I

L

 = 30 mA, See Figure 3-2

Thermal Shutdown Die
Temperature

T

SD

150

°C

Thermal Shutdown Hysteresis

T

HYS

10

°C

Thermal Resistance Junction to 
Case

RthetaJA

200

°C/Watt EIA/JEDEC JESD51-751-7 4-

Layer Board

SHDN Input High Threshold

V

IH

45

%V

IN

V

IN

 = 2.5V to 6.0V

SHDN Input Low Threshold

V

IL

15

%V

IN

V

IN

 = 2.5V to 6.0V

ELECTRICAL CHARACTERISTICS (CONTINUED)

V

IN

 = V

OUT

 + 1V, I

L

 = 0.1 mA, C

L

 = 3.3 µF, SHDN > V

IH

, T

A

 = 25°C, unless otherwise noted. BOLDFACE type specifications apply 

for junction temperature (Note 8) of -40°C to +125°C.

Parameters

Sym

Min

Typ

Max

Units

Conditions

Note

1: V

R

 is the regulator output voltage setting.

2:

3: Regulation is measured at a constant junction temperature using low duty cycle pulse testing. Load regulation is tested 

over a load range from 0.1 mA to the maximum specified output current. Changes in output voltage due to heating 
effects are covered by the thermal regulation specification.

4: Dropout voltage is defined as the input to output differential at which the output voltage drops 2% below its nominal value 

measured at a 1V differential.

5: Thermal Regulation is defined as the change in output voltage at a time t after a change in power dissipation is applied, 

excluding load or line regulation effects. Specifications are for a current pulse equal to I

LMAX

 at V

IN

 = 6V for t = 10 msec.

6: The maximum allowable power dissipation is a function of ambient temperature, the maximum allowable junction tem-

perature and the thermal resistance from junction-to-air (i.e. T

A

, T

J

JA

). Exceeding the maximum allowable power dissi-

pation causes the device to initiate thermal shutdown. Please see Section 4.0, “Thermal Considerations”, of this data 
sheet for more details.

7: The minimum V

IN

 has to meet two conditions: V

IN

 

 2.7V and V

IN

 

 (V

R

 + V

DROPOUT

).

8: The junction temperature of the device is approximated by soaking the device under test at an ambient temperature 

equal to the desired junction temperature. The test time is small enough such that the rise in the junction temperature 
over the ambient temperature is not significant.

TCV

OUT

V

OUTMAX

V

OUTMIN

 10

6

V

OUT

T

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TC1300

DS21385D-page 4

 2001-2012 Microchip Technology Inc.

RESET Output

Voltage Range

V

DET

1.0
1.2


6.0
6.0

V

T

A

 = 0°C to +70°C

T

A

 = – 40°C to +125°C

Reset Threshold

V

TH

2.59

2.63

2.66

V

TC1300R-XX, T

A

 = +25°C

2.55

2.70

TC1300R-XX,
T

= – 40°C to +125°C

2.36

2.40

2.43

TC1300Y-XX, T

A

 = +25°C

2.32

2.47

TC1300Y-XX,
T

= – 40°C to +125°C

Reset Threshold Tempco

V

TH

 / 

T

30

ppm/°C

V

DET

 to Reset Delay

t

RPD

160

µsec

V

DET

 = V

TH

 to (V

TH

 – 100 mV)

Reset Active Timeout Period

t

RPU

140

300

560

msec

RESET Output Voltage Low

V

OL

0.3

V

V

DET

 = V

TH

 min,

I

SINK

 = 1.2 mA

RESET Output Voltage High

V

OH

0.8 V

DET

V

V

DET

 > V

TH

 max,

I

SOURCE

 = 500 µA

ELECTRICAL CHARACTERISTICS (CONTINUED)

V

IN

 = V

OUT

 + 1V, I

L

 = 0.1 mA, C

L

 = 3.3 µF, SHDN > V

IH

, T

A

 = 25°C, unless otherwise noted. BOLDFACE type specifications apply 

for junction temperature (Note 8) of -40°C to +125°C.

Parameters

Sym

Min

Typ

Max

Units

Conditions

Note

1: V

R

 is the regulator output voltage setting.

2:

3: Regulation is measured at a constant junction temperature using low duty cycle pulse testing. Load regulation is tested 

over a load range from 0.1 mA to the maximum specified output current. Changes in output voltage due to heating 
effects are covered by the thermal regulation specification.

4: Dropout voltage is defined as the input to output differential at which the output voltage drops 2% below its nominal value 

measured at a 1V differential.

5: Thermal Regulation is defined as the change in output voltage at a time t after a change in power dissipation is applied, 

excluding load or line regulation effects. Specifications are for a current pulse equal to I

LMAX

 at V

IN

 = 6V for t = 10 msec.

6: The maximum allowable power dissipation is a function of ambient temperature, the maximum allowable junction tem-

perature and the thermal resistance from junction-to-air (i.e. T

A

, T

J

JA

). Exceeding the maximum allowable power dissi-

pation causes the device to initiate thermal shutdown. Please see Section 4.0, “Thermal Considerations”, of this data 
sheet for more details.

7: The minimum V

IN

 has to meet two conditions: V

IN

 

 2.7V and V

IN

 

 (V

R

 + V

DROPOUT

).

8: The junction temperature of the device is approximated by soaking the device under test at an ambient temperature 

equal to the desired junction temperature. The test time is small enough such that the rise in the junction temperature 
over the ambient temperature is not significant.

TCV

OUT

V

OUTMAX

V

OUTMIN

 10

6

V

OUT

T

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DS21385D-page 5

TC1300

2.0

TYPICAL CHARACTERISTICS

Junction temperature (T

J

) is approximated by soaking the device under test at an ambient temperature equal to the

desired Junction temperature. The test time is small enough such that the rise in the Junction temperature over the
Ambient temperature is not significant.

FIGURE 2-1:

Line Regulation vs. 

Temperature.

FIGURE 2-2:

Supply Current vs. 

Temperature.

FIGURE 2-3:

Normalized V

OUT

 vs. 

Temperature.

FIGURE 2-4:

Reset Active Time-out 

Period vs. Temperature.

FIGURE 2-5:

Output Noise vs. Frequency.

FIGURE 2-6:

Dropout Voltage vs. Load 

Current (2.5V).

Note:

The graphs and tables provided following this note are a statistical summary based on a limited number of
samples and are provided for informational purposes only. The performance characteristics listed herein
are not tested or guaranteed. In some graphs or tables, the data presented may be outside the specified
operating range (e.g., outside specified power supply range) and therefore outside the warranted range.

0.000

0.005

0.010

0.015

0.020

0.025

0.030

0.035

-40 -25 -10

5

20

35

50

65

80

95 110 125

Junction Temperature (°C)

Li

ne Regul

at

ion (

%

)

V

OUT

 = 3.0V

V

IN

 = 3.5V to 6.0V

0.00

0.02

0.04

0.06

0.08

0.10

0.12

0.14

-40 -25 -10

5

20 35 50 65 80 95 110 125

Junction Temperature (°C)

Suppl

y Cur

re

nt

 (

m

A)

V

OUT

 = 2.5V

V

OUT

 = 5.0V

V

OUT

 = 3.0V

V

IN

 = V

OUT

 + 1V

2.491

2.492

2.493

2.494

2.495

2.496

2.497

2.498

2.499

2.500

-40 -25 -10

5

20

35

50

65

80

95 110 125

Junction Temperature (°C)

O

u

tput

 Vol

tage (

V

)

V

IN

 = V

OUT

 + 1V

I

OUT

 = 100 µA

V

OUT

 = 2.5V

0

50

100

150

200

250

300

350

400

450

-40 -25 -10

5

20

35

50

65

80

95 110 125

Junction Temperature (°C)

Reset Active Time-out Period 

(ms)

0.01

0.10

1.00

10.00

0.01

0.10

1.00

10.00

100.00

1000.00

Frequency (kHz)

Ou

tp

u

t N

o

is

e

 (µ

V

/lH

z

)

R

LOAD

 = 50 Ohms

C

OUT

 = 1 µF

1

1000

100

10

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0

100

200

300

400

Load Current (mA)

Dr

opout

 Vol

tage (

V

)

T

J

 = +125°C

T

J

 = -40°C

T

J

 = +25°C

V

OUT

 = 2.5V

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TC1300

DS21385D-page 6

 2001-2012 Microchip Technology Inc.

2.0 TYPICAL CHARACTERISTICS

 

(CON’T)

Junction temperature (T

J

) is approximated by soaking the device under test at an ambient temperature equal to the

desired Junction temperature. The test time is small enough such that the rise in the Junction temperature over the
Ambient temperature is not significant.

FIGURE 2-7:

Power Supply Rejection 

Ratio vs. Frequency.

FIGURE 2-8:

Reset Voltage Threshold vs. 

Junction Temperature.

FIGURE 2-9:

Load Regulation vs. 

Temperature.

FIGURE 2-10:

Dropout Voltage vs. Load 

Current (5.0V).

FIGURE 2-11:

Wake-Up Response Time.

FIGURE 2-12:

V

DET 

to Reset Delay vs. 

Temperature.

0

15

30

45

60

10

100

1000

10000

100000 100000

Frequency (Hz)

Power Supply Ripple Rejection 

(dB)

V

IN

 = 3.8V

V

OUT

 = 2.8V

I

OUT

 = 50 mA

C

OUT

 = 10 μF

C

OUTesr

 = 0.25 :

C

BYPASS

 = 0 μF

1k

10k

100k

1M

2.6275

2.6280

2.6285

2.6290

2.6295

2.6300

2.6305

2.6310

2.6315

2.6320

2.6325

2.6330

-40 -25 -10

5

20

35

50

65

80

95 110 125

Junction Temperature (°C)

R

eset

 Vol

tage Thr

eshol

d (

V

)

0.20

0.30

0.40

0.50

0.60

0.70

0.80

0.90

-40 -25 -10

5

20

35

50

65

80

95 110 125

Junction Temperature (°C)

Load Regulation (1 mA to 300 

mA) %

V

IN

 = V

OUT

 + 1V

V

OUT

 = 3.0V

V

OUT

 = 2.5V

V

OUT

 = 5.0V

0

0.05

0.1

0.15

0.2

0.25

0.3

0

100

200

300

400

Load Current (mA)

Dr

opout

 Vol

tage (

V

)

T

J

 = +125°C

T

J

 = -40°C

T

J

 = +25°C

V

OUT

 = 5.0V

0

50

100

150

200

250

300

-40 -25 -10

5

20

35

50

65

80

95 110 125

Junction Temperature (°C)

V

DET

 to RESET Delay Time (µS)

10 mV Overdrive

100 mV Overdrive

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 2001-2012 Microchip Technology Inc.

DS21385D-page 7

TC1300

2.0 TYPICAL CHARACTERISTICS

 

(CON’T)

Junction temperature (T

J

) is approximated by soaking the device under test at an ambient temperature equal to the

desired Junction temperature. The test time is small enough such that the rise in the Junction temperature over the
Ambient temperature is not significant.

FIGURE 2-13:

Load Transient Response 

1 µF Output Capacitor.

FIGURE 2-14:

Line Transient Response 

1 µF Output Capacitor.

FIGURE 2-15:

Load Transient Response 

10 µF Output Capacitor.

FIGURE 2-16:

Line Transient Response 

10 µF Output Capacitor.

FIGURE 2-17:

RESET Output Voltage Low 

vs. Junction Temperature.

FIGURE 2-18:

RESET Output Voltage High 

vs. Junction Temperature.

0.00

0.05

0.10

0.15

0.20

0.25

0.30

-40 -25 -10

5

20

35

50

65

80

95 110 125

Junction Temperature (°C)

RESET V

OL

 (V

)

V

DET

 = V

TH

 - 20 mV

I

SINK

 = 1.2 mA

I

SINK

 = 3.2 mA

3.890

3.900

3.910

3.920

3.930

3.940

3.950

3.960

-40 -25 -10

5

20

35

50

65

80

95 110 125

Junction Temperature (°C)

RESET VO

H (

V

)

V

DET

 = 4.0V

I

SOURCE

 = 500 µA 

I

SOURCE

 = 800 µA 

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TC1300

DS21385D-page 8

 2001-2012 Microchip Technology Inc.

3.0

DETAILED DESCRIPTION

The TC1300 is a combination of a fixed output, low
dropout regulator and a microcontroller
monitor/RESET. Unlike bipolar regulators, the TC1300
supply current does not increase with load current. In
addition, V

OUT

 remains stable and within regulation

over the entire specified operating load range (0 mA to
300 mA) and operating input voltage range (2.7V to
6.0V).

Figure 3-1 shows a typical application circuit. The reg-
ulator is enabled any time the shutdown input (SHDN)
is above V

IH

. The regulator is shutdown (disabled)

when SHDN is at or below V

IL

. SHDN may be con-

trolled by a CMOS logic gate or an I/O port of a micro-
controller. If the SHDN input is not required, it should be
connected directly to the input supply. While in shut-
down, supply current decreases to 30 µA (typical),
V

OUT

 falls to zero and RESET remains valid.

3.1

RESET

 

Output

The RESET output is driven active-low within 160 µsec
of V

DET

 falling through the reset voltage threshold.

RESET is maintained active for a minimum of
140 msec after V

DET

 rises above the reset threshold.

The TC1300 has an active-low RESET output. The out-
put of the TC1300 is valid down to V

DET

 = 1V and is

optimized to reject fast transient glitches on the V

DET

line.

FIGURE 3-1:

Typical Application Circuit.

3.2

Output Capacitor

A 1 µF (min) capacitor from V

OUT

 to ground is required.

A 1 µF capacitor should also be connected from V

IN

 to

GND if there is more than 10 inches of wire between
the regulator and the AC filter capacitor, or if a battery
is used as the power source. As with all low dropout
regulators, a minimum output capacitance is required
to stabilize the output voltage. For the TC1300, a mini-
mum of 1 µF of output capacitance is enough to stabi-
lize the device over the entire operating load and line
range. The selected output capacitor plays an impor-
tant role is compensating the LDO regulator. For the

TC1300, the selected output capacitor equivalent
series resistance (ESR) range is 0.1 ohms to 5 ohms
when using 1 µF of output capacitance, and 0.01 ohms
to 5 ohms when using 10 µF of output capacitance.
Because of the ESR requirement, tantalum and alumi-
num electrolytic capacitors are recommended. Alumi-
num electrolytic capacitors are not recommended for
operation at temperatures below -25°C. When operat-
ing from sources other than batteries, rejection and
transient responses can be improved by increasing the
value of the input and output capacitors and employing
passive filtering techniques.

3.3

Bypass Input (Optional)

An optional 470 pF capacitor connected from the
Bypass input to ground reduces noise present on the
internal reference, which in turn significantly reduces
output noise and improves PSRR performance. This
input may be left unconnected. Larger capacitor values
may be used, but results in a longer time period to rated
output voltage when power is initially applied.

3.4

Turn On Response

The turn-on response is defined as two separate
response categories, Wake-Up Time (t

WK

) and Settling

Time (t

S

).

The TC1300 has a fast Wake-Up Time (10 µsec typi-
cal) when released from shutdown. See Figure 3-2 for
the Wake-Up Time designated as t

WK

. The Wake-Up

Time is defined as the time it takes for the output to rise
to 2% of the V

OUT

 value after being released from

shutdown.

The total turn-on response is defined as the Settling
Time (t

S

) (see Figure 3-2). Settling Time (inclusive with

t

WK

) is defined as the condition when the output is

within 2% of its fully enabled value (50 µsec typical)
when released from shutdown. The settling time of the
output voltage is dependent on load conditions and
output capacitance on V

OUT

 (RC response).

FIGURE 3-2:

Wake-Up Response Time.

TC1300

1

2

3

4

5

6

7

8

V

OUT

C

BYPASS

470 pF
(Optional)

Shutdown Control
(from Power 
Control Logic)

GND

Bypass

V

IN

SHDN

V

OUT

C

1

1 µF

RESET

V

DET

NC

C

2

1 µF

Battery

V

DET

+

RESET

Microcontroller

V

IH

t

S

t

WK

V

OUT

98%

2%

V

IL

SHDN

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 2001-2012 Microchip Technology Inc.

DS21385D-page 9

TC1300

4.0

THERMAL CONSIDERATIONS

4.1

Thermal Shutdown

Integrated thermal protection circuitry shuts the regula-
tor off when the die temperature exceeds 150°C. The
regulator remains off until the die temperature drops to
approximately 140°C. 

4.2

Power Dissipation

The amount of power the regulator dissipates is primar-
ily a function of input and output voltage, and output
current. The following equation is used to calculate
worst case actual power dissipation:

EQUATION

The maximum allowable power dissipation, P

DMAX

, is a

function of the maximum ambient temperature (T

AMAX

),

the maximum recommended die temperature (125°C)
and the thermal resistance from junction-to-air (

JA

).

The MSOP-8 package has a 

JA

 of approximately

200°C/Watt when mounted on a FR4 dielectric copper
clad PC board.

EQUATION

The worst case actual power dissipation equation can
be used in conjunction with the LDO maximum allow-
able power dissipation equation to ensure regulator
thermal operation is within limits. For example:

Find:

EQUATION:

ACTUAL POWER 
DISSIPATION

EQUATION:

MAXIMUM ALLOWABLE 
POWER DISSIPATION

In this example, the TC1300 dissipates a maximum of
only 220 mW; below the allowable limit of 350 mW. In a
similar manner, the maximum actual power dissipation
equation and the maximum allowable power dissipa-
tion equation can be used to calculate maximum cur-
rent and/or input voltage limits. For example, the
maximum allowable V

IN

 is found by substituting the

maximum allowable power dissipation of 350 mW into
the actual power dissipation equation, from which
V

INMAX

 = 4.97V.

4.3

Layout Considerations

The primary path of heat conduction out of the package
is via the package leads. Therefore, layouts having a
ground plane, wide traces at the pads and wide power
supply bus lines combine to lower 

JA 

and, therefore,

increase the maximum allowable power dissipation
limit.

P

D

V

IN MAX

V

OUTMIN

I

LOA DMAX

Where:

P

D

 = worst case actual power dissipation

V

INMAX

 = maximum voltage on V

IN

V

OUTMIN

 = minimum regulator output voltage

I

LOADMAX

 = maximum output (load) current

P

DMAX

T

JMAX

T

AMAX

JA

--------------------------------------------

=

Given:

V

INMAX

=

4.1V

V

OUTMIN

=

3.0V -2.5%

I

LOADMAX

=

200 mA

T

JMAX

=

125°C

T

AMAX

=

55°C

JA

=

200°C/W

P

D

V

IN MAX

V

OUTMIN

I

LOA DMAX

4.1

3.0

.975

=

200

10

3

220 mW

=

P

DMAX

T

JMAX

T

AMAX

JA

--------------------------------------------

=

125

55

200

-------------------------

=

350 mW

=

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TC1300

DS21385D-page 10

 2001-2012 Microchip Technology Inc.

5.0

PACKAGING INFORMATION

5.1

Package Marking Information

Part Number

Marking Code

(XXXXXX)

TC1300R - 2.5VUA

1300RA

TC1300Y - 2.7VUA

1300YF

TC1300R - 2.8VUA

1300RB

TC1300R - 2.85VUA

1300RC

TC1300R - 3.0VUA

1300RD

TC1300R - 3.3VUA

1300RE

8-Lead MSOP

Example:

XXXXXX

YWWNNN

1300RA

YWWNNN

Legend: XX...X

Customer-specific information

Y

Year code (last digit of calendar year)

YY

Year code (last 2 digits of calendar year)

WW

Week code (week of January 1 is week ‘01’)

NNN

Alphanumeric traceability code

  

Pb-free JEDEC designator for Matte Tin (Sn)

*

This package is Pb-free. The Pb-free JEDEC designator (     )
can be found on the outer packaging for this package.

Note:

In the event the full Microchip part number cannot be marked on one line, it will
be carried over to the next line, thus limiting the number of available
characters for customer-specific information.

3

e

3

e

Maker
Microchip Technology Inc.
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