2002-2012 Microchip Technology Inc.
DS21363C-page 1
TC1174
Features
• Extremely Low Supply Current (50
A, Typ.)
• Very Low Dropout Voltage
• 300mA Output Current
• Adjustable Output Voltages
• Power Saving Shutdown Mode
• Bypass Input for Ultra Quiet Operation
• Over Current and Over Temperature Protection
• Space-Saving MSOP Package Option
Applications
• Battery Operated Systems
• Portable Computers
• Medical Instruments
• Instrumentation
• Cellular/GSM/PHS Phones
• Linear Post-Regulators for SMPS
• Pagers
Device Selection Table
Package Type
General Description
The TC1174 is an adjustable output CMOS low dropout
regulator. Total supply current is typically 50
A at full
load (20 to 60 times lower than in bipolar regulators).
TC1174 key features include ultra low noise operation
(plus optional Bypass input); very low dropout voltage
(typically 270mV at full load) and internal feed-forward
compensation for fast response to step changes in
load. Supply current is reduced to 0.05
A (typical) and
V
OUT
falls to zero when the shutdown input is low.
The TC1174 incorporates both over temperature and
over current protection. The TC1174 is stable with an
output capacitor of only 1
F and has a maximum
output current of 300mA.
Typical Application
Part Number
Output
Voltage
(V)
Package
Junction
Temp. Range
TC1174VOA
Adjustable
8-Pin SOIC
-40°C to +125°C
TC1174VUA
Adjustable
8-Pin MSOP
-40°C to +125°C
8-Pin SOIC
1
2
3
4
V
IN
5
6
7
8
NC
SHDN
V
OUT
GND
NC
ADJ
8-Pin MSOP
1
2
3
4
V
IN
5
6
7
8
NC
V
OUT
GND
NC
ADJ
TC1174VOA
TC1174VUA
Bypass
SHDN
Bypass
TC1174
1
2
3
4
5
6
7
8
V
OUT
V
OUT
C
BYPASS
470pF
(Optional)
Shutdown
Control
(from Power
Control Logic)
GND
NC
ADJ
V
IN
V
IN
NC
NC
Bypass
SHDN
R1
470K
470K
R2
C1
1
μF
V
OUT
= V
REF
x
[
— + 1
]
R1
R2
+
300mA CMOS LDO with Shutdown and V
REF
Bypass
TC1174
DS21363C-page 2
2002-2012 Microchip Technology Inc.
1.0
ELECTRICAL
CHARACTERISTICS
Absolute Maximum Ratings*
Input Voltage .........................................................6.5V
Output Voltage.................. (V
SS
– 0.3V) to (V
IN
+ 0.3V)
Power Dissipation................Internally Limited (Note 5)
Maximum Voltage on Any Pin ........ V
IN
+0.3V to -0.3V
Operating Temperature Range...... -40°C < T
J
< 125°C
Storage Temperature..........................-65°C to +150°C
*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.
TC1174 ELECTRICAL SPECIFICATIONS
Electrical Characteristics: V
IN
= V
OUT
+ 1V, I
L
= 0.1
A, C
L
= 3.3
F, SHDN > V
IH
, T
A
= 25°C, unless otherwise noted. Boldface
type specifications apply for junction temperatures of -40°C to +125°C.
Symbol
Parameter
Min
Typ
Max
Units
Test Conditions
V
IN
Input Operating Voltage
2.7
—
6.0
V
Note 6
I
OUT
MAX
Maximum Output Current
300
—
—
mA
V
REF
Reference Voltage
1.165
1.20
1.235
V
V
OUT
/
T
V
OUT
Temperature Coefficient
—
40
—
ppm/°C
Note 1
V
OUT
/
V
IN
Line Regulation
—
0.05
0.35
%
(V
R
+ 1V)
V
IN
6V
V
OUT
/V
OUT
Load Regulation
—
1.1
2.0
%
I
L
= 0.1mA to I
OUT
MAX
(Note 2)
V
IN
-V
OUT
Dropout Voltage
—
—
—
20
80
270
30
160
480
mV
I
L
= 0.1mA
I
L
= 100mA
I
L
= 300mA (Note 3)
I
SS1
Supply Current
—
50
90
A
SHDN = V
IH
I
SS2
Shutdown Supply Current
—
0.05
0.5
A
SHDN = 0V
PSRR
Power Supply Rejection Ratio
—
60
—
dB
F
RE
–1kHz
I
OUT
SC
Output Short Circuit Current
—
550
650
mA
V
OUT
= 0V
V
OUT
/
P
D
Thermal Regulation
—
0.04
—
V/W
Note 4
eN
Output Noise
—
260
—
nV/
Hz F = 10kHz, I
L
= I
OUT
MAX
470pF from Bypass to GND
SHDN Input
V
IH
SHDN Input High Threshold
45
—
—
%V
IN
V
IL
SHDN Input Low Threshold
—
—
15
%V
IN
ADJ Input
I
ADJ
Adjustable Input Leakage Current
—
50
—
pA
1:
2:
Regulation is measured at a constant junction temperature using low duty cycle pulse testing. Load regulation is tested over a load range
from 0.1mA to the maximum specified output current. Changes in output voltage due to heating effects are covered by the thermal
regulation specification.
3:
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.
4:
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
L
MAX
at V
IN
= 6V for T = 10 msec.
5:
The maximum allowable power dissipation is a function of ambient temperature, the maximum allowable junction temperature and the
thermal resistance from junction-to-air (i.e., T
A
, T
J
,
JA
). Exceeding the maximum allowable power dissipation causes the device to initiate
thermal shutdown. Please see Section 4.0 Thermal Considerations for more details.
6:
The minimum V
IN
has to justify the conditions: V
IN
V
R
+ V
DROPOUT
and V
IN
2.7V for I
L
= 0.1mA to I
OUT
MAX
.
TC V
OUT
= (V
OUT
MAX
– V
OUT
MIN
) x 10
6
V
OUT
x
T
2002-2012 Microchip Technology Inc.
DS21363C-page 3
TC1174
2.0
PIN DESCRIPTIONS
The descriptions of the pins are listed in Table 2-1.
TABLE 2-1:
PIN FUNCTION TABLE
Pin No.
(8-Pin SOIC)
(8-Pin MSOP)
Symbol
Description
1
V
OUT
Regulated voltage output.
2
GND
Ground terminal.
3
NC
No connect.
4
ADJ
Output voltage adjust terminal. Output voltage setting is programmed with a resistor divider from
V
OUT
to this input. A capacitor may also be added to this input to reduce output noise.
5
Bypass
Reference bypass input. Connecting a 470pF to this input further reduces output noise.
6
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 shutdown, output
voltage falls to zero and supply current is reduced to 0.05
A (typical).
7
NC
No connect.
8
V
IN
Unregulated supply input.
TC1174
DS21363C-page 4
2002-2012 Microchip Technology Inc.
3.0
DETAILED DESCRIPTION
The TC1174 is an adjustable low drop-out regulator.
Unlike bipolar regulators, the TC1174’s supply current
does not increase with load current. In addition, V
OUT
remains stable and within regulation over the entire
0mA to I
OUT
MAX
operating load current range, (an
important consideration in RTC and CMOS RAM
battery back-up applications).
Figure 3-1 shows a typical application circuit. The
regulator is enabled any time the shutdown input
(SHDN) is at or above V
IH
, and shutdown (disabled)
when SHDN is at or below V
IL
. SHDN may be
controlled by a CMOS logic gate, or I/O port of a
microcontroller. If the SHDN input is not required, it
should be connected directly to the input supply. While
in shutdown, supply current decreases to 0.05
A
(typical), V
OUT
falls to zero.
FIGURE 3-1:
TYPICAL APPLICATION
CIRCUIT
3.1
Bypass Input
A 470pF capacitor connected from the Bypass input to
ground reduces noise present on the internal
reference, which in turn significantly reduces output
noise. If output noise is not a concern, 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.
3.2
Output Capacitor
A 1
F (min) capacitor from V
OUT
to ground is required.
The output capacitor should have an effective series
resistance greater than 0.1
and less than 5.0. A 1F
capacitor should 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. Aluminum electrolytic or tantalum
capacitor types can be used. (Since many aluminum
electrolytic capacitors freeze at approximately -30°C,
solid tantalums are recommended for applications
operating below -25°C.) When operating from sources
other than batteries, supply-noise rejection and
transient response can be improved by increasing the
value of the input and output capacitors and employing
passive filtering techniques.
3.3
Adjust Input
The output voltage setting is determined by the values
of R1 and R2 (Figure 3-1). The ohmic values of these
resistors should be between 470K and 3M to minimize
bleeder current.
The output voltage setting is calculated using the
following equation.
EQUATION 3-1:
The voltage adjustment range of the TC1174 is from
V
REF
to (V
IN
– 0.05V).
TC1174
1
2
3
4
5
6
7
8
V
OUT
V
OUT
C
BYPASS
470pF
(Optional)
Shutdown
Control
(from Power
Control Logic)
C1
1
μF
GND
NC
ADJ
V
IN
NC
Bypass
SHDN
R1
470K
470K
R2
C2
1
μF
Battery
+
+
+
–
V
OUT
= V
REF
x
[
+ 1
]
R1
R2
2002-2012 Microchip Technology Inc.
DS21363C-page 5
TC1174
4.0
THERMAL CONSIDERATIONS
4.1
Thermal Shutdown
Integrated thermal protection circuitry shuts the
regulator off when 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
primarily a function of input and output voltage, and
output current. The following equation is used to
calculate worst case actual power dissipation:
EQUATION 4-1:
The maximum allowable power dissipation (Equation
4-2) is a function of the maximum ambient temperature
(T
A
MAX
), the maximum allowable die temperature
(T
J
MAX
) and the thermal resistance from junction-to-air
(
JA
). The 8-Pin SOIC package has a
JA
of approxi-
mately 160°C/Watt, while the 8-Pin MSOP package
has a
JA
of approximately 200°C/Watt.
EQUATION 4-2:
Equation 4-1 can be used in conjunction with Equation
4-2 to ensure regulator thermal operation is within
limits. For example:
Given:
V
IN
MAX
= 3.0V + 10%
V
OUT
MIN
= 2.7V – 0.5%
I
LOAD
MAX
= 250mA
T
J
MAX
= 125°C
T
A
MAX
= 55°C
8-Pin MSOP Package
Find: 1. Actual power dissipation
2. Maximum allowable dissipation
Actual power dissipation:
P
D
(V
IN
MAX
– V
OUT
MIN
)I
LOAD
MAX
= [(3.0 x 1.1) – (2.7 x .995)]250 x 10
–3
= 155mW
Maximum allowable power dissipation:
In this example, the TC1174 dissipates a maximum of
155mW; below the allowable limit of 350mW. In a
similar manner, Equation 4-1 and Equation 4-2 can be
used to calculate maximum current and/or input
voltage limits. For example, the maximum allowable
V
IN
is found by substituting the maximum allowable
power dissipation of 350mW into Equation 4-1, from
which V
IN
MAX
= 4.1V.
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.
Where:
P
D
(V
IN
MAX
– V
OUT
MIN
)I
LOAD
MAX
P
D
V
IN
MAX
V
OUT
MIN
I
LOAD
MAX
= Worst case actual power dissipation
= Minimum regulator output voltage
= Maximum output (load) current
= Maximum voltage on V
IN
P
D
MAX
= (T
J
MAX
– T
A
MAX
)
JA
Where all terms are previously defined.
P
D
MAX
= (T
J
MAX
– T
A
MAX
)
JA
= (125 – 55)
200
= 350mW
TC1174
DS21363C-page 6
2002-2012 Microchip Technology Inc.
5.0
TYPICAL CHARACTERISTICS
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.
Output Noise
FREQUENCY (kHz)
NOISE (
μ
V/
√
HZ)
10.0
1.0
0.01
0.01
1
10
100
1000
0.1
0.0
R
LOAD
= 50Ω
C
OUT
= 1
μF
0.012
0.010
0.008
0.004
0.002
0.000
-0.002
-0.004
0.006
-40
° -20° 0° 20° 40° 60° 80° 100° 120°
TEMPERATURE (
°
C)
Line Regulation
LINE REGULATION (%)
2.00
1.80
1.60
1.20
1.00
0.80
0.60
0.40
0.20
0.00
1.40
-40
° -20° 0° 20° 40° 60° 80° 100° 120°
TEMPERATURE (
°
C)
Load Regulation
LOAD REGULATION (%)
1 to 300mA
1 to 50mA
1 to 100mA
0.40
0.35
0.30
0.25
0.20
0.15
0.10
0.05
0.00
0
50
100
150
200
250
300
LOAD CURRENT (mA)
DROPOUT VOLTAGE (V)
100.0
90.0
70.0
80.0
50.0
40.0
60.0
-40
° -20° 0° 20° 40° 60° 80° 100° 120°
TEMPERATURE (
°C)
Supply Current
SUPPLY CURRENT (
μ
A)
3.075
3.025
2.925
2.975
-40
° -20° 0° 20° 40° 60° 80° 100° 120°
TEMPERATURE (
°C)
V
OUT
vs. Temperature
V
OUT
(V)
125
°C
8
85
°C
C
70
°C
25
°C
0
°C
C
-40
°C
V
IN
= 4V
I
LOAD
= 100μA
C
LOAD
= 3.3
μF
2002-2012 Microchip Technology Inc.
DS21363C-page 7
TC1174
6.0
PACKAGING INFORMATION
6.1
Package Marking Information
Package marking data not available at this time.
6.2
Taping Form
Component Taping Orientation for 8-Pin MSOP Devices
Package
Carrier Width (W)
Pitch (P)
Part Per Full Reel
Reel Size
8-Pin MSOP
12 mm
8 mm
2500
13 in
Carrier Tape, Number of Components Per Reel and Reel Size
PIN 1
User Direction of Feed
Standard Reel Component Orientation
for TR Suffix Device
W
P
Component Taping Orientation for 8-Pin SOIC (Narrow) Devices
Package
Carrier Width (W)
Pitch (P)
Part Per Full Reel
Reel Size
8-Pin SOIC (N)
12 mm
8 mm
2500
13 in
Carrier Tape, Number of Components Per Reel and Reel Size
Standard Reel Component Orientation
for TR Suffix Device
PIN 1
User Direction of Feed
P
W
TC1174
DS21363C-page 8
2002-2012 Microchip Technology Inc.
6.3
Package Dimensions
8-Pin MSOP
.122 (3.10)
.114 (2.90)
.122 (3.10)
.114 (2.90)
.043 (1.10)
MAX.
.006 (0.15)
.002 (0.05)
.016 (0.40)
.010 (0.25)
.197 (5.00)
.189 (4.80)
.008 (0.20)
.005 (0.13)
.028 (0.70)
.016 (0.40)
6
° MAX.
.026 (0.65) TYP.
PIN 1
Dimensions: inches (mm)
Note:
For the most current package drawings, please see the Microchip Packaging Specification located
at http://www.microchip.com/packaging
2002-2012 Microchip Technology Inc.
DS21363C-page 9
TC1174
.050 (1.27) TYP.
8
°
MAX.
PIN 1
.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)
.
8-Pin SOIC
Dimensions: inches (mm)
Note:
For the most current package drawings, please see the Microchip Packaging Specification located
at http://www.microchip.com/packaging
TC1174
DS21363C-page 10
2002-2012 Microchip Technology Inc.
REVISION HISTORY
Revision C (November 2012)
Added a note to each package outline drawing.