TC1173
TC1173-2 2/2/00 TelCom Semiconductor reserves the right to make changes in the circuitry and specifications of its devices.
GENERAL DESCRIPTION
The TC1173 is a precision output (typically
0.5%)
CMOS low dropout regulator. Total supply current is typi-
cally 50
A at full load
(20 to 60 times lower than in bipolar
regulators!).
TC1173 key features include ultra low noise operation
(plus optional Bypass input); very low dropout voltage
(typically 240mV at full load) and internal feed-forward
compensation for fast response to step changes in load. An
error output (ERROR) is asserted when the TC1173 is out-
of-regulation (due to a low input voltage or excessive output
current). ERROR can be set as a low battery warning or as
a processor RESET signal (with the addition of an external
RC network). Supply current is reduced to 0.05
A (typical)
and V
OUT
and ERROR fall to zero when the shutdown input
is low.
The TC1173 incorporates both over-temperature and
over-current protection. The TC1173 is stable with an output
capacitor of only 1
F and has a maximum output current of
300mA.
300mA CMOS LDO with Shutdown, ERROR Output and Bypass
FEATURES
s
Extremely Low Supply Current for Longer Battery
Life!
s
Very Low Dropout Voltage
s
Guaranteed 300mA Output
s
Standard or Custom Output Voltages
s
ERROR Output Can be Used as a Low Battery
Detector or Processor Reset Generator
s
Power-Saving Shutdown Mode
s
Bypass Input for Ultra-Quiet Operation
s
Over-Current and Over-Temperature Protection
s
Space-Saving MSOP Package Option
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
PIN CONFIGURATION
1
2
3
4
V
IN
5
6
7
8
NC
ERROR
V
OUT
GND
NC
Bypass
SHDN
1
2
3
4
V
IN
5
6
7
8
NC
ERROR
V
OUT
GND
NC
Bypass
SHDN
TC1173VUA
TC1173VOA
MSOP
SOIC
ORDERING INFORMATION
Part
Junction
Number
Package
Temp. Range
TC1173-xxVOA
8-Pin SOIC
40
C to +125
C
TC1173-xxVUA
8-Pin MSOP
40
C to +125
C
Available Output Voltages:
2.5, 2.8, 3.0, 3.3, 5.0
xx indicates output voltages
Other output voltages are available. Please contact TelCom
Semiconductor for details.
TYPICAL APPLICATION
TC1173
1
2
3
4
5
6
7
8
V
OUT
Shutdown Control
(from Power Control Logic)
C1
1
F
GND
NC
V
IN
NC
SHDN
Bypass
C
BYPASS
470pF
(Optional)
ERROR
R3
1M
V
IN
ERROR
2
TC1173
300mA CMOS LDO With Shutdown,
ERROR Output, And Bypass
TC1173-2 2/2/00
ABSOLUTE MAXIMUM RATINGS*
Input Voltage .............................................................. 6.5V
Output Voltage ........................... (V
SS
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.) ................ +300
C
*Absolute Maximum Ratings indicate device operation limits beyond dam-
age may occur. Device operation beyond the limits listed in
Electrical
Characteristics is not recommended.
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
Test Conditions
Min
Typ
Max
Units
V
IN
Input Operating Voltage
--
--
6.0
V
I
OUT
MAX
Maximum Output Current
300
--
--
mA
V
OUT
Output Voltage
Note 1
--
V
R
0.5%
--
V
V
R
- 2.5%
V
R
+ 2.5%
V
OUT
/
T
V
OUT
Temperature Coefficient
Note 2
--
--
--
ppm/
C
40
V
OUT
/
V
IN
Line Regulation
(V
R
+ 1V) < V
IN
< 6V
--
0.05
0.35
%
V
OUT
/V
OUT
Load Regulation
I
L
= 0.1mA to I
OUT
MAX
(Note 3)
--
0.5
2.0
%
V
IN
V
OUT
Dropout Voltage (Note 4)
I
L
= 0.1mA
--
20
30
mV
I
L
= 100mA
80
160
I
L
= 300mA
240
480
I
SS1
Supply Current
SHDN = V
IH
--
50
90
A
I
SS2
Shutdown Supply Current
SHDN = 0V
--
0.05
0.5
A
PSRR
Power Supply Rejection Ratio
F
RE
1kHz
--
60
--
dB
I
OUT
SC
Output Short Circuit Current
V
OUT
= 0V
--
550
650
mA
V
OUT
P
D
Thermal Regulation
Note 5
--
0.04
--
V/W
eN
Output Noise
F = 1kHz, C
OUT
= 1
F,
--
260
--
nV/
Hz
R
LOAD
= 50
SHDN Input
V
IH
SHDN Input High Threshold
45
--
--
%V
IN
V
IL
SHDN Input Low Threshold
--
--
15
%V
IN
ERROR 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
--
0.95 x V
R
--
V
V
OL
ERROR Positive Hysteresis
Note 7
--
50
--
mV
NOTES: 1. V
R
is the user-programmed regulator output voltage setting.
2. T
C
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 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 = 10msec.
6. 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
Thermal Considerations section of this data sheet for more details.
7. Hysteresis voltage is referenced to V
R
.
3
300mA CMOS LDO With Shutdown,
ERROR Output, And Bypass
TC1173
TC1173-2 2/2/00
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 and ERROR is disabled.
ERROR Output
ERROR is driven low whenever V
OUT
falls out of regu-
lation by more than 5% (typical). This condition may be
caused by low input voltage, output current limiting, or
thermal limiting.
The ERROR threshold is 5% below rated V
OUT
regard-
less of the programmed output voltage value (e.g., ERROR
= V
OL
at 4.75V (typ) for a 5.0V regulator and 2.85V (typ) for
a 3.0V regulator). ERROR output operation is shown in
Figure 2. Note that ERROR is active when V
OUT
is at or
below V
TH
, and inactive when V
OUT
is above V
TH
+ V
H
.
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 C3 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. 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 electro-
lytic 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.
DETAILED DESCRIPTION
The TC1173 is a fixed output, low drop-out regulator.
Unlike bipolar regulators, the TC1173 supply current does not
increase with load current. In addition, V
OUT
remains stable and
within regulation at very low load currents (an important consid-
eration in RTC and CMOS RAM battery back-up applications).
TC1173 pin functions are detailed below:
PIN DESCRIPTIONS
Pin
No.
Symbol
Description
1
V
OUT
Regulated voltage output
2
GND
Ground terminal
3
NC
No connect
4
Bypass
Reference bypass input. Connecting a 470pF
to this input further reduces output noise.
5
ERROR
Out-of-Regulation Flag (Open Drain Out-
put). This output goes low when V
OUT
is out-
of-tolerance by approximately -5%.
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
Figure 1 shows a typical application circuit. The regula-
tor is enabled any time the shutdown input (SHDN) is above
V
IH
, and shutdown (disabled) when SHDN is at or below V
IL
.
Figure 1: Typical Application Circuit
Figure 2: ERROR Output Operation
V
OUT
V
TH
V
IH
Hysteresis (V
H
)
V
OL
ERROR
TC1173
1
2
3
4
5
6
7
8
V
OUT
V
OUT
Shutdown Control
(from Power Control Logic)
C1
1
F
GND
NC
V
IN
NC
SHDN
Bypass
C
BYPASS
470pF
(Optional)
ERROR
R3
1M
V
IN
ERROR
4
TC1173
300mA CMOS LDO With Shutdown,
ERROR Output, And Bypass
TC1173-2 2/2/00
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 150
C. The regulator
remains off until the die temperature drops to approximately
140
C.
Power Dissipation
The amount of power the regulator dissipates is prima-
rily a function of input and output voltage, and output current.
The following equation is used to calculate worst case
actual
power dissipation:
P
D
(V
IN
MAX
V
OUT
MIN
)I
LOAD
MAX
Where:
P
D
= worst case actual power dissipation
V
IN
MAX
= maximum voltage on V
IN
V
OUT
MIN
= minimum regulator output voltage
I
LOAD
MAX
= maximum output (load) current
Equation 1.
The maximum
allowable power dissipation (Equation 2)
is a function of the maximum ambient temperature (T
A
MAX
),
the maximum allowable die temperature (125
C), and the
thermal resistance from junction-to-air (
JA
). The 8-Pin
SOIC package has a
JA
of approximately
160
C/Watt,
while the 8-Pin MSOP package has a
JA
of approximately
200
C/Watt; both when mounted on a single layer FR4
dielectric copper clad PC board.
P
DMAX
= (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
IN
MAX
= 3.0V
10%
V
OUT
MIN
= 2.7V
0.5%
I
LOADMAX
= 250mA
T
J
MAX
= 125
C
T
A
MAX
= 55
C
JA
= 200
C/W
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:
P
D
(T
JMAX
T
AMAX
)
JA
= (125 55)
200
= 350mW
In this example, the TC1173 dissipates a maximum of
only 155mW; far below the allowable limit of 350mW. 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 substitut-
ing the maximum allowable power dissipation of 350mW
into Equation 1, from which V
IN
MAX
= 4.1V.
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.
5
300mA CMOS LDO With Shutdown,
ERROR Output, And Bypass
TC1173
TC1173-2 2/2/00
TYPICAL CHARACTERISTICS
Output Noise
FREQUENCY (KHz)
Noise (
V/
/ HZ)
10.0
1.0
0.01
0.01
1
10
100
1000
0.1
0.0
R
LOAD
= 50
C
OUT
= 1
F
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 (%)
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 vs. Load Current
DROPOUT VOLTAGE (V)
Power Supply Rejection Ratio
FREQUENCY (KHz)
30dB
35dB
40dB
45dB
50dB
55dB
60dB
65dB
70dB
75dB
80dB
100
1K
10K
10
1M
100K
V
OUT
= 5V
R
LOAD
= 50
V
INAC
= 50mV p-p
C
OUT
= 1
F
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 (
A)
PSRR (dB)
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
3.075
3.025
2.925
2.975
40 20
0
20
40
60
80 100 120
TEMPERATURE (
C)
VOUT vs. Temperature
V
OUT
(V)
125
C
85
C
70
C
25
C
0
C
40
C
V
IN
= 4V
I
LOAD
= 100
A
C
LOAD
= 3.3
F
6
TC1173
300mA CMOS LDO With Shutdown,
ERROR Output, And Bypass
TC1173-2 2/2/00
TAPE AND REEL DIAGRAMS
PIN 1
PIN 1
Component Taping Orientation for 8-Pin SOIC (Narrow) Devices
User Direction of Feed
User Direction of Feed
Standard Reel Component Orientation
for TR Suffix Device
Reverse Reel Component Orientation
for RT Suffix Device
W
P
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
PIN 1
PIN 1
Component Taping Orientation for 8-Pin MSOP Devices
User Direction of Feed
User Direction of Feed
Standard Reel Component Orientation
for TR Suffix Device
Reverse Reel Component Orientation
for RT Suffix Device
W
P
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
7
300mA CMOS LDO With Shutdown,
ERROR Output, And Bypass
TC1173
TC1173-2 2/2/00
PACKAGE DIMENSIONS
Dimensions: inches (mm)
Sales Offices
TelCom Semiconductor, Inc.
1300 Terra Bella Avenue
P.O. Box 7267
Mountain View, CA 94039-7267
TEL: 650-968-9241
FAX: 650-967-1590
E-Mail: liter@telcom-semi.com
TelCom Semiconductor, GmbH
Lochhamer Strasse 13
D-82152 Martinsried
Germany
TEL: (011) 49 89 895 6500
FAX: (011) 49 89 895 6502 2
TelCom Semiconductor H.K. Ltd.
10 Sam Chuk Street, Ground Floor
San Po Kong, Kowloon
Hong Kong
TEL: (011) 852-2350-7380
FAX: (011) 852-2354-9957
.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 (Narrow)
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
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