300mA CMOS LDO w ith Shutdo wn ERROR Output and Bypass
Features
• Extremely Low Supply Current for Longer Battery Life
• Very Low Dr opout Voltage
• 300mA Output Current
• Standard or Custom Output Voltages
• ERROR
Output Can Be Used as a Low Battery
Detector or Processor Reset Generator
• Power Saving Shutdown Mode
• Bypass Input for Ultra Quiet Operation
• Over Current and O ver Temperature Protection
• Space-Saving MSOP Package Option
Applications
• Battery Operated Systems
• PortableComputers
• Medical Instruments
• Instrumentation
• Cellular/GSM/PHSPhones
• Linear Post-Regulators for SMPS
• Pagers
Device Selection Table
Part NumberPackage
TC1173-xxVOA8-Pin SOIC-40°C to +125°C
TC1173-xxVUA8-Pin MSO P-40°C to +125°C
NOTE: xx indicates outputvoltages
Available Output Voltages: 2.5, 2.8, 3.0, 3.3, 5.0.
Otheroutputvoltagesareavailable.Please contactMicrochip
T echnology Inc. for details.
Junction
Temp. Range
General Description
The TC1173 is a precision output (typically ±0.5%)
CMOS low dropout regulator. Total supply current is
typically 50µA 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 i nternal 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
low battery war ning or as a processor RESET
canbesetasa
signal
(with the addition of an external RC network). Supply
current is reduced to 0.05µA (typical) and V
ERROR
fall to zero when the shutdown input is low.
OUT
and
The TC1173 incorporates both over temperature and
over current pr otection. The TC1173 is stable with an
output capacitor of only 1µF and has a maximum
output current of 300mA.
Typical Application
V
OUT
1
V
C1
1µF
OUT
2
GND
+
TC1173
3
NC
45
Bypass
C
BYPASS
470pF
(Optional)
ERROR
Shutdown Control
(from Power Control Logic)
V
NC
SHDN
8
IN
7
6
R3
1M
V
IN
ERROR
Package Type
8-Pin MSOP
1
V
OUT
2
GND
Bypass
2002 Microchip TechnologyInc.DS21362B-page 1
NC
TC1173VUA
3
4
8
7
6
5
V
IN
NC
SHDN
ERROR
V
OUT
GND
Bypass
NC
8-Pin SOIC
1
2
TC1173VOA
3
4
8
7
6
5
V
IN
NC
SHDN
ERROR
TC1173
1.0ELECTRICAL
CHARACTERISTICS
Absolute Maximum Ratings*
Input Voltage .........................................................6.5V
Output Voltage..................(V
– 0.3V) to (VIN+0.3V)
SS
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 f or
extended periods may affectdevice reliability.
Power Dissipation................Internally Limited (Note 6)
Maximum Voltage on Any Pin ........V
Operating Temperature Range......-40°C < T
+0.3V to -0.3V
IN
<125°C
J
Storage Temperature..........................-65°C to +150°C
TC1173 ELECTRICAL SPECIFICATIONS
Electrical Characteristics: VIN=V
type specifications apply for junctiontemperaturesof -40°C to +125°C.
SymbolParameterMinTypMaxUnitsTest Conditions
V
IN
I
OUTMAX
V
OUT
/∆TV
∆V
OUT
/∆V
∆V
OUT
∆V
OUT/VOUT
V
IN-VOUT
I
SS1
I
SS2
InputOperating Voltage2.7—6.0VNote 8
Maximum Output Current300——mA
Output Voltage—
Temperature Coefficient—40—ppm/°CNote 2
OUT
Line Regulation—0.050.35%(VR+1V)≤ VIN ≤ 6V
IN
Load Regulation—0.52.0%IL= 0.1mA to I
DropoutVoltage—
Supply Current—5090µASHDN =V
Shutdown Supply Current—0.050.5µASHDN =0V
PSRRPower Supply Rejection Ratio—60—dBF
I
OUTSC
∆V
OUT
/∆P
Output Short Circuit Current—550650mAV
Thermal Regulation—0.04—V/WNote 5
D
eNOutput Noise—260—nV/√Hz
Input
SHDN
V
IH
V
IL
SHDN Input High Threshold45——%V
SHDN Input Low Threshold——15%V
ERROR Output
V
MIN
V
OL
V
TH
V
OL
Note 1: VRis the user-programmed 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
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
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
6: The maximum allowable power dissipation is a function of ambient temperature, the maximum allowable junction temperature and the
7: Hysteresis voltage is referenced by V
8: The minimum V
MinimumOperatingVoltage1.0——V
Output Logic Low Voltage——400mV1 mA Flows to ERROR
ERROR Threshold Voltage—0.95 x V
ERROR Positive Hysteresis—50—mVNote 7
TC V
=(V
OUT
OUTMAX–VOUTMIN
V
OUT
from 0.1mA to the maximum specified output current. Changes in output voltage due to heating effects are covered by the thermal regulation specification.
1V differential.
line regulation effects. Specifications are for a current pulse equal to I
thermal resistance from junction-to-air (i.e., T
thermal shutdown. Please see Section 4.0 Thermal Considerations for more details.
, θJA). Exceeding the maximum allowable power dissipation causes the device to initiate
A,TJ
.
R
and VIN≥ 2.7V for IL= 0.1mA to I
DROPOUT
OUTMAX
.
IH,
OUT
OUTMAX
=1µF,
(Note 3)
DS21362B-page 2
2002 Microchip TechnologyInc.
2.0PIN DESCRIPTIONS
ThedescriptionsofthepinsarelistedinTable2-1.
TABLE 2-1:PIN FUNCTION TABLE
Pin No.
(8-Pin SOIC)
(8-Pin MSOP)
1V
2GNDGround terminal.
3NCNo connect.
4BypassReference bypass input. Connecting a 470pFto this input further reduces outputnoise.
5ERROR
6SHDN
7NCNo connect.
8V
SymbolDescription
OUT
Regulated voltage output.
Out-of-RegulationFlag.(Open drain output). This output goes low whenV
by approximately – 5%.
Shutdown control input. The regulator is fully enabled when a logic high is applied to this input.
The regulator enters shutdown when a logiclowis appliedto thisinput. During shutdown, output
voltage falls to zero and supply current is reduced to 0.05µA(typical).
Unregulatedsupply input.
IN
TC1173
is out-of-tolerance
OUT
2002 Microchip TechnologyInc.DS21362B-page 3
TC1173
3.0DETAILED DESCRIPTION
The TC1173 is a fixed output, l ow drop-out regulator.
Unlike bipolar regulators, the TC1173’s supply current
does not increase with load current. In addition, V
remains s table and within regulation over the entire
0mA t o I
OUTMAX
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 VIH, and shutdown (disabled)
when SHDN
is at or below VIL. 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 s upply. While
in shutdown, supply current decreases to 0.05µA
(typical), V
falls to zero and ERROR is disabled.
OUT
FIGURE 3-1:TYPICAL APPLICATION
CIRCUIT
V
OUT
+
C1
1µF
(from Power Control Logic)
C
BYPASS
470pF
(Optional)
1
V
OUT
2
GND
TC1173
3
NC
4
Bypass
Shutdown Control
C3 required only if ERROR
is used as a processor RESET signal.
V
NC
SHDN
ERROR
8
IN
7
6
5
(see text)
1M
+
R3
C3
0.2µF
3.1ERROR Output
ERROR is driven low whenever V
regulation by more than – 5% (typical). This condition
may be caused by low input voltage, output current
limiting, or thermal limiting. The ERROR
5% below rated V
regardless of t he programmed
OUT
output voltage value (e.g., ERROR
(typ.) for a 5.0V r egulator and 2.85V (typ.) for a 3.0V
regulator). ERROR
output operation is shown in
Figure 3-2.
Note that ERROR
V
, and inactive when V
TH
is active when V
is above VTH+VH.
OUT
As shown in Figure 3-1, ERROR
battery low flag, or as a processor RESET
the addition oftiming capacitor C3). R1 x C3 should be
chosen to maintain ERROR
RESET
input for at least 200 msec to allow time for the
below VIHof the processor
system to stabilize. Pull-up resistor R1 can be tied to
V
OUT,VIN
or any other voltage less than (VIN+0.3V).
falls out of
OUT
threshold is
=VOLat 4.75V
is at or below
OUT
canbeusedasa
OUT
C2
1µF
+
–
Battery
RESET or
Battery Low
signal (with
FIGURE 3-2:ERROR OU TPUT
OPERATION
V
OUT
V
ERROR
V
V
TH
IH
OL
HYSTERESIS (VH)
3.2Output Capacitor
A1µF (min) capacitor from V
recommended. The output capacitor should have an
effective series resistance greater than 0.1Ω and less
than 5.0Ω.A1µF capacitor should be connected from
V
to GND if there is more t han 10 inches of wire
IN
betweenthe 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 f rom sources other than batteries,
supply-noise rejection and transient response can be
improved by i ncreasing the value of the input and
output capacitors and employing passive filtering
techniques.
to ground is
OUT
3.3Bypass 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.Ifoutputnoiseisnota concern,thisinputmaybe
left unconnected. Larger capacitor values may be
used, but resultsin a longer time period to rated output
voltage when power is initially applied.
DS21362B-page 4
2002 Microchip TechnologyInc.
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