Document Outline
- Return to Contents
- TC1072
- List of Figures
- 1. Typical Application Circuit
- 2. ERROR Output Operation
- Features
- Applications
- General Description
- Typical Application
- Ordering Information
- Pin Configuration
- Absolute Maximum Ratings
- Electrical Characteristics
- Electrical Characteristics
- Pin Description
- Detailed Description
- ERROR Open Drain Output
- Output Capacitor
- Bypass Input
- Thermal Considerations
- Package Dimensions
- Sales Offices
- TC1073
- List of Figures
- 1. Typical Application Circuit
- 2. ERROR Output Operation
- Features
- Applications
- Typical Application
- General Description
- Ordering Information
- Pin Configuration
- Absolute Maximum Ratings
- Electrical Characteristics
- Electrical Characteristics
- Pin Description
- Detailed Description
- ERROR Open Drain Output
- Output Capacitor
- Bypass Input
- Thermal Considerations
- Marking
- Package Dimensions
- Sales Offices
TC1072
1
PRELIMINARY INFORMATION
TC1072-01
6/16/97
50mA CMOS LDO WITH SHUTDOWN,
ERROR OUTPUT AND V
REF
BYPASS
TC1072
FEATURES
s
Zero Ground Current for Longer Battery Life!
s
Very Low Dropout Voltage
s
Guaranteed 50mA Output
s
High Output Voltage Accuracy
s
Standard or Custom Output Voltages
s
Power-Saving Shutdown Mode
s
ERROR Ouput can be Used as a Low Battery
Detector, or Processor Reset Generator
s
Bypass Input for Ultra-quiet Operation
s
Over-Current and Over-Temperature Protection
s
Space-Saving SOT-23A-6 Package
s
Pin Compatible Upgrades for Bipolar Regulators
APPLICATIONS
s
Battery Operated Systems
s
Portable Computers
s
Medical Instruments
s
Instrumentation
s
Cellular / GSM / PHS Phones
s
Linear Post-Regulator for SMPS
s
Pagers
GENERAL DESCRIPTION
The TC1072 is a high accuracy (typically
0.5%) CMOS
upgrade for older (bipolar) low dropout regulators. Designed
specifically for battery-operated systems, the TC1072's
50mA CMOS LDO WITH SHUTDOWN, ERROR OUTPUT AND V
REF
BYPASS
TYPICAL APPLICATION
TelCom Semiconductor reserves the right to make changes in the circuitry and specifications ot its devices.
CMOS construction eliminates wasted ground current, sig-
nificantly extending battery life. Total supply current is
typically 50
A at full load (
20 to 60 times lower than in bipolar
regulators!).
TC1072 key features include ultra low noise operation
(plus optional Bypass input); very low dropout voltage (typi-
cally 100mV at full load) and internal feed-forward compen-
sation for fast response to step changes in load. An error
output (ERROR) is asserted when the TC1072 is out-of-
regulation (due to a low input voltage or excessive output
current). ERROR can be used as a low battery warning or as
a processor RESET signal (with the addition of an external
RC network). Supply current is reduced to less than 1
A,
and both V
OUT
and ERROR are disabled when the shutdown
input is low. The TC1072 incorporates both over-tempera-
ture and over-current protection.
The TC1072 is stable with an output capacitor of only
1
F and has a maximum output current of 50mA. For higher
output current versions, please see the TC1107, TC1108
and TC1073 (I
OUT
= 300mA) data sheets.
1
F
Shutdown Control
(from Power Control Logic)
TC1072
V
IN
1
1M
2
3
4
6
5
V
IN
V
OUT
ERROR
Bypass
C
BYPASS
470pF
SHDN
GND
V
OUT
ERROR
PIN CONFIGURATION
ORDERING INFORMATION
Output
Junction
Part No.
Voltage **(V) Package
Temp. Range
TC1072-2.5VCH
2.5
SOT-23A-6* 40
C to +125
C
TC1072-2.7VCH
2.7
SOT-23A-6* 40
C to +125
C
TC1072-3.0VCH
3.0
SOT-23A-6* 40
C to +125
C
TC1072-3.3VCH
3.3
SOT-23A-6* 40
C to +125
C
TC1072-5.0VCH
5.0
SOT-23A-6* 40
C to +125
C
NOTE: *SOT-23A-6 is equivalent to the EIAJ (SC-74A)
** Other output voltages available. Please contact TelCom
Semiconductor for details
NOTE: *SOT-23A-6 is equivalent to the EIAJ (SC-74A)
TC1072
(SOT-23A-6*)
TOP VIEW
1
3
5
4
6
2
SHDN
ERROR
GND
V
OUT
Bypass
V
IN
PRELIMINARY INFORMATION
TC1072
2
50mA CMOS LDO WITH SHUTDOWN,
ERROR OUTPUT AND V
REF
BYPASS
TC1072-01
6/16/97
ELECTRICAL CHARACTERISTICS:
V
IN
= V
OUT
+ 1V, I
L
= 0.1mA, C
L
= 3.3
F, SHDN > V
IH
, T
A
= 25
C, unless other-
wise specified.BOLDFACE type specifications apply for junction temperatures of
40
C to +125
C.
Symbol
Parameter
Test Conditions
Min
Typ
Max
Units
V
IN
Input Operating Voltage
--
--
6.5
V
I
OUTMAX
Maximum Output Current
50
--
--
mA
V
OUT
Output Voltage
Note 1
V
R
2.5%
V
R
0.5%
V
R
+ 2.5%
V
TC V
OUT
V
OUT
Temperature Coefficient
Note 2
--
--
ppm/
C
40
V
OUT
/
V
IN
Line Regulation
(V
R
+ 1V) < V
IN
< 6V
--
0.05
--
%/V
V
OUT
/V
OUT
Load Regulation
I
L
= 0.1mA to I
OUTMAX
--
0.5
--
%
(Note 3)
V
IN
V
OUT
Dropout Voltage (Note 4)
I
L
= 0.1mA
--
5
--
mV
I
L
= 20mA
65
I
L
= 50mA
95
(Note 4)
I
GND
Ground Pin Current
I
L
= I
OUTMAX,
(Note 5)
--
0
--
A
I
IN
Supply Current
SHDN = V
IH
, I
L
= 0
--
50
--
A
I
INSD
Shutdown Supply Current
SHDN = 0V
--
--
0.05
A
PSRR
Power Supply Rejection Ratio
F
RE
1kHz
--
64
--
dB
I
OUTSC
Output Short Circuit Current
V
OUT
= 0V
--
200
450
mA
V
OUT
/
P
D
Thermal Regulation
Note 6
--
0.04
--
%/W
eN
Output Noise
I
L
= I
OUTMAX
--
260
--
nV/
Hz
470pF from Bypass to GND
SHDN Input
V
IH
SHDN Input High Threshold
V
IN
= 2.5V to 6.5V
45
--
--
%V
IN
V
IL
SHDN Input Low Threshold
V
IN
= 2.5V to 6.5V
--
--
15
%V
IN
ABSOLUTE MAXIMUM RATINGS*
Input Voltage ................................................................. 7V
Output Voltage .................................. ( 0.3) to (V
IN
+ 0.3)
Power Dissipation .................... Internally Limited (Note 7)
Operating Temperature .................... 40
C < T
J
< 125
C
Storage Temperature ............................ 65
C to +150
C
Maximum Voltage on Any Pin ........... V
IN
+ 0.3V to 0.3V
Lead Temperature (Soldering, 10 Sec.) ................ +260
C
*Stresses beyond 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 beyond
those indicated in the operational sections of the specifications is not
implied. Exposure to absolute maximum rating conditions for extended
periods may affect device reliability.
TC1072
3
PRELIMINARY INFORMATION
TC1072-01
6/16/97
50mA CMOS LDO WITH SHUTDOWN,
ERROR OUTPUT AND V
REF
BYPASS
Pin No.
(SOT-23A-6)
Symbol
Description
1
V
IN
Unregulated supply input.
2
GND
Ground terminal.
3
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 microamp
(typical).
4
ERROR
Out-of-Regulation Flag. (Open drain output). This output goes low when V
OUT
is out-of-
tolerance by approximately 5%.
5
Bypass
Reference bypass input. Connecting a 470pF to this input further reduces output noise.
6
V
OUT
Regulated voltage output.
ELECTRICAL CHARACTERISTICS:
V
IN
= V
OUT
+ 1V, I
L
= 0.1mA, C
L
= 3.3
F, SHDN > V
IH
, T
A
= 25
C, unless otherwise noted.
Symbol
Parameter
Test Conditions
Min
Typ
Max
Units
ERROR Open Drain Output
V
MIN
Minimum Operating Voltage
1.0
--
--
V
V
OL
Output Logic Low Voltage
1mA Flows to ERROR
--
--
400
mV
V
TH
ERROR Threshold Voltage
See Figure 2
--
0.95 x V
R
--
V
V
HYS
ERROR Positive Hysteresis
Note 8
--
50
--
mV
NOTES: 1. V
R
is the regulator output voltage setting. V
R
= 2.5V, 2.7V, 3.0V, 3.2V, 3.3V, 3.8V 5.0V.
2. TC V
OUT
= (V
OUTMAX
V
OUTMIN
)
x 10
6
V
OUT
x
T
3. Regulation is measured at a constant junction temperature using low duty cycle pulse testing. Load regulation is tested over a load
range from 0.1mA 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.
5. Ground pin current is the regulator pass transistor gate current. The total current drawn from the input supply is the sum of the load
current, ground current and supply current (i.e. I
IN
= I
SUPPLY
+ I
GND
+ I
LOAD
).
6. 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 = 10msec.
7. 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
, q
JA
). Exceeding the maximum allowable power dissipation causes the device to
initiate thermal shutdown. Please see
Thermal Considerations section of this data sheet for more details.
8. Hysteresis voltage is referenced by V
R
.
PIN DESCRIPTION
PRELIMINARY INFORMATION
TC1072
4
50mA CMOS LDO WITH SHUTDOWN,
ERROR OUTPUT AND V
REF
BYPASS
TC1072-01
6/16/97
DETAILED DESCRIPTION
The TC1072 is a precision fixed output voltage regula-
tor. (If an adjustable version is desired, please see the
TC1070 or TC1071 data sheets.) Unlike the bipolar regula-
tors, the TC1072 supply current does not increase with load
current. In addition, V
OUT
remains stable and within regula-
tion at very low load currents (an important consideration in
RTC and CMOS RAM battery back-up applications).
Figure 1 shows a typical application circuit. The regula-
tor 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) and V
OUT
falls to zero volts and ERROR is open-
circuited.
ERROR Open Drain Output
ERROR is driven low whenenver V
OUT
falls out of
regulation by more than 5% (typical). The condition my be
caused by low input voltage, output current limiting, or
thermal limiting. The ERROR output voltage value (e.g.
ERROR = V
OL
at 4.75 (typ) for a 5.0V regulator and 2.85 (typ)
for a 3.0V regulator). ERROR ouput operation is shown in
Figure 2.
Note that ERROR is active when V
OUT
falls to V
TH
, and
inactive when V
OUT
rises above V
TH
= V
HYS.
As shown in Figure 1, ERROR can be used as a battery
low flag, or as a processor RESET signal (with the addition
of timing capacitor C2). R1 x C2 should be chosen to
maintain ERROR below V
IH
of the processor RESET input
for at least 200msec to allow time for the system to stabilize.
Pull-up resistor R1 can be tied to V
OUT
, V
IN
or any other
voltage less than (V
IN
+0.3V).
Output Capacitor
A 1
F (min) capacitor from V
OUT
to ground is recom-
mended. The output capacitor should have an effective
series resistance of 5
or less, and a resonant frequency
above 1MHz. A 1
F 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 capaci-
tor 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.
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.
Thermal Considerations
Thermal Shutdown
Integrated thermal protection circuitry shuts the regula-
tor off when die temperature exceeds 160
C. The regulator
remains off until the die temperature drops to approximately
150
C.
Power Dissipation
The amount of power the regulator dissipates is prima-
rily a function of input and output voltage, and output current.
Figure 1. Typical Application Circuit
1
F
C1
0.2
F
C2
R1
1M
V
+
C3, 470pF
C2 Requires Only
if ERROR is used as a
Processor RESET Signal
(See Text)
Shutdown Control
(to CMOS Logic or Tie
to V
IN
if unused)
BATTLOW
or RESET
TC1072
V
IN
BATTERY
Bypass
V
OUT
ERROR
SHDN
GND
V
OUT
1
F
Figure 2. ERROR Output Operation
V
IH
V
OL
ERROR
V
TH
V
OUT
HYSTERESIS (V
HYS
)
TC1072
5
PRELIMINARY INFORMATION
TC1072-01
6/16/97
50mA CMOS LDO WITH SHUTDOWN,
ERROR OUTPUT AND V
REF
BYPASS
The following equation is used to calculate worst case
actual power dissipation:
P
D
(V
INMAX
V
OUTMIN
)I
LOADMAX
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
Equation 1.
The maximum
allowable power dissipation (Equation 2)
is a function of the maximum ambient temperature (T
AMAX
),
the maximum allowable die temperature (125
C) and the
thermal resistance from junction-to-air (
JA
). SOT-23A-6
packag has a
JA
of approximately
220
C/Watt when
mounted on a single layer FR4 dielectric copper clad PC
board.
P
D MAX
= (T
JMAX
T
AMAX)
JA
Where all terms are previously defined.
Equation 2.
Equation 1 can be used in conjunction with Equation 2
to ensure regulator thermal operation is within limits. For
example:
Given:
V
INMAX
= 3.0V
10%
V
OUTMIN
= 2.7V
0.5V
I
LOAD
= 40mA
T
AMAX
= 55
C
Find:
1. Actual power dissipation
2. Maximum allowable dissipation
Actual power dissipation:
P
D
(V
INMAX
V
OUTMIN
)I
LOADMAX
= [(3.0 x 1.05) (2.7 x .995)]40 x 10
3
= 18.5mW
Maximum allowable power dissipation:
P
DMAX
= (T
JMAX
T
AMAX
)
JA
= (125 55)
220
= 318mW
In this example, the TC1072 dissipates a maximum of
only 60mW; far below the allowable limit of 318mW. In a
similar manner, Equation 1 and Equation 2 can be used to
calculate maximum current and/or input voltage limits.
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 in-
crease the maximum allowable power dissipation limit.
PRELIMINARY INFORMATION
TC1072
6
50mA CMOS LDO WITH SHUTDOWN,
ERROR OUTPUT AND V
REF
BYPASS
TC1072-01
6/16/97
Sales Offices
TelCom Semiconductor
1300 Terra Bella Avenue
P.O. Box 7267
Mountain View, CA 94039-7267
TEL: 415-968-9241
FAX: 415-967-1590
E-Mail: liter@c2smtp.telcom-semi.com
Printed in the U.S.A.
TelCom Semiconductor H.K. Ltd.
10 Sam Chuk Street, 6/F
San Po Kong
Kowloon
Hong Kong
TEL: 852-2324-0122
FAX: 852-2354-9957
TelCom Semiconductor
Austin Product Center
9101 Burnet Rd. Suite 214
Austin, TX 78758
TEL: 512-873-7100
FAX: 512-873-8236
SOT-23A-6*
PACKAGE DIMENSIONS
Dimensions: inches (mm)
.069 (1.75)
.059 (1.50)
.118 (3.00)
.102 (2.60)
.020 (0.50)
.014 (0.35)
.037 (0.95)
REFERENCE
.118 (3.00)
.110 (2.80)
.057 (1.45)
.035 (0.90)
.006 (0.15)
.000 (0.00)
.022 (0.55)
.014 (0.35)
10
MAX.
.008 (0.20)
.004 (0.09)
SOT-23A-6
&
= part number code + temperature range and voltage
TC1072 (V)
Code
2.5
E1
2.7
E2
3.0
E3
3.3
E4
5.0
E6
represents year and quarter code
represents lot ID number
NOTE: *SOT-23A-6 is equivalent to the EIAJ (SC-74A)
TC1073
1
PRELIMINARY INFORMATION
TC1073-01 6/5/97
100mA CMOS LDO WITH SHUTDOWN,
ERROR OUTPUT AND V
REF
BYPASS
GENERAL DESCRIPTION
The TC1073 is a high accuracy (typically
0.5%) CMOS
upgrade for older (bipolar) low dropout regulators such as
the LP2980. Designed specifically for battery-operated sys-
tems, the TC1073's CMOS construction eliminates wasted
ground current, significantly extending battery life. Total
supply current is typically 50
A at full load (
20 to 60 times
lower than in bipolar regulators!).
TC1073 key features include ultra low noise operation
(plus optional Bypass input); very low dropout voltage (typi-
cally 200mV at full load) and internal feed-forward compen-
sation for fast response to step changes in load. An error
output (ERROR) is asserted when the TC1073 is out-of-
regulation (due to a low input voltage or excessive output
current). ERROR can be used as a low battery warning or as
a processor RESET signal (with the addition of an external
RC network). Supply current is reduced to less than 1
A,
and both V
OUT
and ERROR are disabled when the shutdown
input is low. The TC1073 incorporates both over-tempera-
ture and over-temeprature protection.
The TC1073 is stable with an output capacitor of only
1
F and has a maximum output current of 100mA. For
higher output current versions, please see the TC1107,
TC1108 (I
OUT
= 300mA) data sheets.
TC1073
FEATURES
s
Zero Ground Current for Longer Battery Life!
s
Very Low Dropout Voltage
s
Guaranteed 100mA Output
s
High Output Voltage Accuracy
s
Standard or Custom Output Voltages
s
Power-Saving Shutdown Mode
s
ERROR Ouput can be Used as a Low Battery
Detector, or Processor Reset Generator
s
Bypass Input for Ultra-quiet Operation
s
Over-Current and Over-Temperature Protection
s
Space-Saving SOT-23A-6 Package
s
Pin Compatible Upgrades for Bipolar Regulators
APPLICATIONS
s
Battery Operated Systems
s
Portable Computers
s
Medical Instruments
s
Instrumentation
s
Cellular / GSM / PHS Phones
s
Linear Post-Regulator for SMPS
s
Pagers
100mA CMOS LDO WITH SHUTDOWN, ERROR OUTPUT AND V
REF
BYPASS
TYPICAL APPLICATION
TelCom Semiconductor reserves the right to make changes in the circuitry and specifications ot its devices.
1
F
Shutdown Control
(from Power Control Logic)
TC1073
V
IN
1
1M
2
3
4
6
5
V
IN
V
OUT
ERROR
Bypass
C
BYPASS
470pF
SHDN
GND
V
OUT
ERROR
PIN CONFIGURATION
ORDERING INFORMATION
Output
Junction
Part No.
Voltage**
Package
Temp. Range
TC1073-2.5VCH
2.5V
SOT-23A-6* 40
C to +125
C
TC1073-2.7VCH
2.7V
SOT-23A-6* 40
C to +125
C
TC1073-3.0VCH
3.0V
SOT-23A-6* 40
C to +125
C
TC1073-3.3VCH
3.3V
SOT-23A-6* 40
C to +125
C
TC1073-5.0VCH
5.0V
SOT-23A-6* 40
C to +125
C
NOTE:
*SOT-23A-6 is equivalent to the EIAJ (SC-74)
** Other output voltages available. Please contact TelCom
Semiconductor for details
NOTE: *SOT-23A-6 is equivalent to the EIAJ (SC-74)
TC1073
(SOT-23A-6*)
TOP VIEW
1
3
5
4
6
2
SHDN
ERROR
GND
V
OUT
Bypass
V
IN
TC1073
2
100mA CMOS LDO WITH SHUTDOWN,
ERROR OUTPUT AND V
REF
BYPASS
PRELIMINARY INFORMATION
TC1073-01 6/5/97
ELECTRICAL CHARACTERISTICS:
V
IN
= V
OUT
+ 1V, I
L
= 0.1mA, C
L
= 3.3
F, SHDN > V
IH
, T
A
= 25
C, unless otherwise noted.
Symbol
Parameter
Test Conditions
Min
Typ
Max
Units
V
IN
Input Operating Voltage
Note 9
--
--
6.5
V
I
OUTMAX
Maximum Output Current
Note 9
100
--
--
mA
V
OUT
Output Voltage
Notes 1, 9
V
R
2.5%
V
R
0.5%
V
R
+ 2.5%
V
TC V
OUT
V
OUT
Temperature Coefficient
Note 2, 9
20
--
ppm/
C
40
V
OUT
/
V
IN
Line Regulation
(V
R
+ 1V) < V
IN
< 6V
--
0.05
--
%
V
OUT
/V
OUT
Load Regulation
I
L
= 0.1mA to I
OUTMAX
--
0.5
--
%
(Note 3)
V
IN
V
OUT
Dropout Voltage (Note 4)
I
L
= 0.1mA
--
20
--
mV
I
L
= 20mA
70
I
L
= 50mA
100
I
L
=100mA
200
(Note 4)
I
GND
Ground Pin Current
I
L
= I
OUTMAX,
(Note 5, 9)
--
0
--
A
I
IN
Supply Current
SHDN = V
IH
, I
L
= 0
--
50
80
A
I
INSD
Shutdown Supply Current
SHDN = 0V
--
--
0.05
A
R
OUT
Output Resistance during Shutdown
SHDN < V
IL
100 x V
R
160 x V
R
--
k
PSRR
Power Supply Rejection Ratio
F
RE
1kHz
--
64
--
dB
I
OUTSC
Output Short Circuit Current
V
OUT
= 0V
--
300
500
mA
V
OUT
/
P
D
Thermal Regulation
Note 6
--
0.04
--
%/W
T
SD
Thermal Shutdown Die Temperature
--
160
--
C
T
SD
Thermal Shutdown Hysteresis
--
10
--
C
eN
Output Noise
I
L
= I
OUTMAX
--
260
--
nV/
Hz
470pF from Bypass to GND
SHDN Input
V
IH
SHDN Input High Threshold
V
IN
= 2.5V to 6.5V
45
--
--
%V
IN
V
IL
SHDN Input Low Threshold
V
IN
= 2.5V to 6.5V
--
--
15
%V
IN
ABSOLUTE MAXIMUM RATINGS*
Input Voltage ................................................................. 7V
Output Voltage .................................. ( 0.3) to (V
IN
+ 0.3)
Power Dissipation .................... Internally Limited (Note 7)
Operating Temperature .................... 40
C < T
J
< 125
C
Storage Temperature ............................ 65
C to +150
C
Maximum Voltage On Any Pin .......... V
IN
+ 0.3V to 0.3V
*Stresses beyond 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 beyond
those indicated in the operational sections of the specifications is not
implied. Exposure to absolute maximum rating conditions for extended
periods may affect device reliability.
TC1073
3
PRELIMINARY INFORMATION
TC1073-01 6/5/97
100mA CMOS LDO WITH SHUTDOWN,
ERROR OUTPUT AND V
REF
BYPASS
PIN DESCRIPTION
Pin No.
(SOT-23A-6)
Symbol
Description
1
V
IN
Unregulated supply input.
2
GND
Ground terminal.
3
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 microamp (typical).
4
ERROR
Out-of-Regulation Flag. (Open drain output). This output goes low when V
OUT
is out-of-tolerance
by approximately 5%.
5
Bypass
Reference bypass input. Connecting a 470pF to this input further reduces output noise.
6
V
OUT
Regulated voltage output.
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.
Symbol
Parameter
Test Conditions
Min
Typ
Max
Units
ERROR Open Dranin Output
V
MIN
Minimum Operating Voltage
1.0
--
--
V
V
OL
Output Logic Low Voltage
1mA Flows to ERROR
--
--
400
mV
V
TH
ERROR Threshold Voltage
See Figure 2
--
0.95 x V
R
--
V
V
HYS
ERROR Positive Hysteresis
Note 8
--
50
--
mV
NOTES: 1. V
R
is the regulator output voltage setting. (V
R
= 2.5V, 2.7V, 3.0V, 3.3V, 5.0V).
2. TC V
OUT
= (V
OUTMAX
V
OUTMIN
)
x 10
6
V
OUT
x
T
3. Regulation is measured at a constant junction temperature using low duty cycle pulse testing. Load regulation is tested over a load
range from 0.1mA 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.
5. Ground pin current is the regulator pass transistor gate current. The total current drawn from the input supply is the sum of the load
current, ground current and supply current (i.e. I
IN
= I
SUPPLY
+ I
GND
+ I
LOAD
).
6. 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 = 10msec.
7. 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
, q
JA
). Exceeding the maximum allowable power dissipation causes the device to
initiate thermal shutdown. Please see
Thermal Considerations section of this data sheet for more details.
8. Hysteresis voltage is referenced by V
R
.
9. Boldface type specifications apply for junction temperatures of 40
C to +125
C.
TC1073
4
100mA CMOS LDO WITH SHUTDOWN,
ERROR OUTPUT AND V
REF
BYPASS
PRELIMINARY INFORMATION
TC1073-01 6/5/97
DETAILED DESCRIPTION
The TC1073 is a precision fixed output voltage regula-
tor. (If an adjustable version is desired, please see the
TC1070 or TC1071 data sheets.) Unlike the bipolar regula-
tors, the TC1073 supply current does not increase with load
current. In addition, V
OUT
remains stable and within regula-
tion at very low load currents (an important consideration in
RTC and CMOS RAM battery back-up applications).
Figure 1 shows a typical application circuit. The regula-
tor 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) and V
OUT
falls to zero volts and ERROR is open-
circuited.
ERROR Open Drain Output
ERROR is driven low whenenver V
OUT
falls out of
regulation by more than 5% (typical). The condition my be
caused by low input voltage, output current limiting, or
thermal limiting. The ERROR output voltage value (e.g.
ERROR = V
OL
at 4.75 (typ) for a 5.0V regulator and 2.85 (typ)
for a 3.0V regulator). ERROR ouput operation is shown in
Figure 2.
Note that ERROR is active when V
OUT
falls to V
TH
, and
inactive when V
OUT
rises above V
TH
= V
HYS.
As shown in Figure 1, ERROR can be used as a battery
low flag, or as a processor RESET signal (with the addition
of timing capacitor C2). R1 x C2 should be chosen to
maintain ERROR below V
IH
of the processor RESET input
for at least 200msec to allow time for the system to stabilize.
Pull-up resistor R1 can be tied to V
OUT
, V
IN
or any other
voltage less than (V
IN
+0.3V).
Output Capacitor
A 1
F (min) capacitor from V
OUT
to ground is recom-
mended. The output capacitor should have an effective
series resistance of 5
or less, and a resonant frequency
above 1MHz. A 1
F 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 capaci-
tor 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.
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.
Thermal Considerations
Thermal Shutdown
Integrated thermal protection circuitry shuts the regula-
tor off when die temperature exceeds 160
C. The regulator
remains off until the die temperature drops to approximately
150
C.
Power Dissipation
The amount of power the regulator dissipates is prima-
rily a function of input and output voltage, and output current.
Figure 1. Typical Application Circuit
1
F
C1
0.2
F
C2
R1
1M
V
+
C3, 470pF
C2 Requires Only
if ERROR is used as a
Processor RESET Signal
(See Text)
Shutdown Control
(to CMOS Logic or Tie
to V
IN
if unused)
BATTLOW
or RESET
TC1073
V
IN
BATTERY
Bypass
V
OUT
ERROR
SHDN
GND
V
OUT
1
F
Figure 2. ERROR Output Operation
V
IH
V
OL
ERROR
V
TH
V
OUT
HYSTERESIS (V
HYS
)
TC1073
5
PRELIMINARY INFORMATION
TC1073-01 6/5/97
100mA CMOS LDO WITH SHUTDOWN,
ERROR OUTPUT AND V
REF
BYPASS
The following equation is used to calculate worst case
actual power dissipation:
P
D
(V
INMAX
V
OUTMIN
)I
LOADMAX
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
Equation 1.
The maximum
allowable power dissipation (Equation 2)
is a function of the maximum ambient temperature (T
AMAX
),
the maximum allowable die temperature (125
C) and the
thermal resistance from junction-to-air (
JA
). SOT-23A-6
packag has a
JA
of approximately
220
C/Watt when
mounted on a single layer FR4 dielectric copper clad PC
board.
P
D MAX
= (T
JMAX
T
JMAX)
JA
Where all terms are previously defined.
Equation 2.
Equation 1 can be used in conjunction with Equation 2
to ensure regulator thermal operation is within limits. For
example:
Given:
V
INMAX
= 3.0V
10%
V
OUTMIN
= 2.7V
0.5V
I
LOAD
= 98mA
T
AMAX
= 55
C
Find:
1. Actual power dissipation
2. Maximum allowable dissipation
Actual power dissipation:
P
D
(V
INMAX
V
OUTMIN
)I
LOADMAX
= [(3.0 x 1.1) (2.7 x .995)]40 x 10
3
= 60mW
Maximum allowable power dissipation:
P
DMAX
= (T
JMAX
T
AMAX
)
JA
= (125 55)
220
= 318mW
In this example, the TC1073 dissipates a maximum of
only 60mW; far below the allowable limit of 318mW. In a
similar manner, Equation 1 and Equation 2 can be used to
calculate maximum current and/or input voltage limits. For
example, the maximum allowable V
IN
is found by sustituting
the maximum allowable power dissipation of 318mW into
Equation 1, from which V
INMAX
= 5.9V.
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 in-
crease the maximum allowable power dissipation limit.
TC1073
6
100mA CMOS LDO WITH SHUTDOWN,
ERROR OUTPUT AND V
REF
BYPASS
PRELIMINARY INFORMATION
TC1073-01 6/5/97
Sales Offices
TelCom Semiconductor
1300 Terra Bella Avenue
P.O. Box 7267
Mountain View, CA 94039-7267
TEL: 415-968-9241
FAX: 415-967-1590
E-Mail: liter@c2smtp.telcom-semi.com
Printed in the U.S.A.
TelCom Semiconductor H.K. Ltd.
10 Sam Chuk Street, 6/F
San Po Kong
Kowloon
Hong Kong
TEL: 852-2324-0122
FAX: 852-2354-9957
TelCom Semiconductor
Austin Product Center
9101 Burnet Rd. Suite 214
Austin, TX 78758
TEL: 512-873-7100
FAX: 512-873-8236
SOT-23A-6*
PACKAGE DIMENSIONS
Dimensions: inches (mm)
.069 (1.75)
.059 (1.50)
.118 (3.00)
.102 (2.60)
.020 (0.50)
.014 (0.35)
.037 (0.95)
REFERENCE
.118 (3.00)
.110 (2.80)
.057 (1.45)
.035 (0.90)
.006 (0.15)
.000 (0.00)
.022 (0.55)
.014 (0.35)
10
MAX.
.008 (0.20)
.004 (0.09)
SOT-23A-6
&
= part number code + temperature range and voltage
TC1073 (V)
Code
2.5
F1
2.7
F2
3.0
F3
3.3
F4
5.0
F6
represents year and quarter code
represents lot ID number
NOTE: *SOT-23A-6 is equivalent to the EIAJ (SC-74)
MARKING
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