TC1301B-DAAVUATR Datasheet, PDF (13/28 Pages) Microchip Technology – Dual LDO with Microcontroller RESET Function

TC1301A/B
4.0 TC1301B PIN DESCRIPTIONS
The descriptions of the pins are listed in Table 4-1.
TABLE 4-1: TC1301B PIN FUNCTION TABLE
Pin No.
Name
Function
1
RESET Push-pull output pin that will remain low while V_DET is below the reset threshold and for
300 ms after V_OUT1 rises above the reset threshold
2
V_OUT1 Regulated output voltage #1 capable of 300 mA
3
GND Circuit ground pin
4
Bypass Internal reference bypass pin. A 10 nF external capacitor can be used to further reduce
output noise and improve PSRR performance
5
SHDN2 Output #2 shutdown control Input
6
V_OUT2 Regulated output voltage #2 capable of 150 mA
7
V_IN
Unregulated input voltage pin
8
SHDN1 Output #1 shutdown control input
4.1 RESET Output Pin
The push-pull output pin is used to monitor the output
voltage (V_OUT1). If V_OUT1 is less than the threshold
voltage, the RESET output will be held in the low state.
As V_OUT1 rises above the threshold, the RESET output
will remain in the low state for 300 ms and then change
to the high state, indicating that the voltage on V_OUT1 is
above the threshold.
4.2 Regulated Output Voltage #1
(V_OUT1)
Connect V_OUT1 to the positive side of the V_OUT1
capacitor and load. It is capable of 300 mA maximum
output current. For the TC1301B, V_OUT1 can be turned
ON and OFF using the SHDN1 input pin.
4.3 Circuit Ground Pin (GND)
Connect GND to the negative side of the input and
output capacitor. Only the LDO internal circuitry bias
current flows out of this pin (200 µA maximum).
4.4 Reference Bypass Input
By connecting an external 10 nF capacitor (typical) to
bypass, both outputs (V_OUT1 and V_OUT2) will have less
noise and improved Power Supply Ripple Rejection
(PSRR) performance. The LDO output voltage start-up
time will increase with the addition of an external
bypass capacitor. By leaving this pin unconnected, the
start-up time will be minimized.
4.5 Output Voltage #2 Shutdown
(SHDN2)
ON/OFF control is performed by connecting SHDN2 to
its proper level. When this pin is connected to a voltage
less than 15% of V_IN, V_OUT2 will be OFF. If this pin is
connected to a voltage that is greater than 45% of V_IN,
V_OUT2 will be turned ON.
4.6 Regulated Output Voltage #2
(V_OUT2)
Connect V_OUT2 to the positive side of the V_OUT2
capacitor and load. This pin is capable of a maximum
output current of 150 mA. V_OUT2 can be turned ON and
OFF using SHDN2.
4.7 Unregulated Input Voltage Pin
(V_IN)
Connect the unregulated input voltage source to V_IN. If
the input voltage source is located more than several
inches away or is a battery, a typical minimum input
capacitance of 1 µF and 4.7 µF is recommended.
4.8 Output Voltage #1 Shutdown
(SHDN1)
ON/OFF control is performed by connecting SHDN1 to
its proper level. When this pin is connected to a voltage
less than 15% of V_IN, V_OUT1 will be OFF. If this pin is
connected to a voltage that is greater than 45% of V_IN,
V_OUT1 will be turned ON.
© 2008 Microchip Technology Inc.
DS21798C-page 13