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Power-Good
Manual Reset Pins (MR1 and MR2)
Sense (VSENSE1, VSENSE2)
FB1 and FB2
RESET Indicator
VIN1 and VIN2
VOUT1 and VOUT2
TPS70745, TPS70748
TPS70751, TPS70758
TPS70702
SLVS291D – MAY 2000 – REVISED DECEMBER 2007
The PG1 is an open drain, active high output terminal that indicates the status of the VOUT1 regulator. When the
VOUT1 reaches 95% of its regulated voltage, PG1 goes to a high impedance state. It goes to a low impedance
state when it is pulled below 95% (for example, doing an overload condition) of its regulated voltage. The open
drain output of the PG1 terminal requires a pull-up resistor.
MR1 and MR2 are active low input terminals used to trigger a reset condition. When either MR1 or MR2 is pulled
to logic low, a POR (RESET) occurs. These terminals have a 6-
A pull-up current to V
IN1.
The sense terminals of fixed-output options must be connected to the regulator output, and the connection
should be as short as possible. Internally, sense connects to high-impedance, wide-bandwidth amplifiers through
a resistor-divider network and noise pickup feeds through to the regulator output. It is essential to route the
sense connection in such a way to minimize or avoid noise pickup. Adding RC networks between the VSENSE
terminals and VOUT terminals to filter noise is not recommended because these networks can cause the
regulators to oscillate.
FB1 and FB2 are input terminals used for adjustable-output devices and must be connected to the external
feedback resistor divider. FB1 and FB2 connections should be as short as possible. It is essential to route them
in such a way as to minimize or avoid noise pickup. Adding RC networks between the FB terminals and VOUT
terminals to filter noise is not recommended because these networks can cause the regulators to oscillate.
The TPS707xx features a RESET (SVS, POR, or Power-On Reset). RESET can be used to drive power-on reset
circuitry or a low-battery indicator. RESET is an active low, open drain output that indicates the status of the
VOUT2 regulator and both manual reset pins (MR1 and MR2). When VOUT2 exceeds 95% of its regulated voltage,
and MR1 and MR2 are in the high impedance state, RESET goes to a high-impedance state after 120ms delay.
RESET goes to a low-impedance state when VOUT2 is pulled below 95% (for example, an overload condition) of
its regulated voltage. To monitor VOUT1, the PG1 output pin can be connected to MR1 or MR2. The open drain
output of the RESET terminal requires a pullup resistor. If RESET is not used, it can be left floating.
VIN1 and VIN2 are input to the regulators. Internal bias voltages are powered by VIN1.
VOUT1 and VOUT2 are output terminals of the LDO.
Copyright 2000–2007, Texas Instruments Incorporated
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