7

LTC1536

TI I G DIAGRA S

Pushbutton Reset Function Timing

1536 TD02

PBR

RST

SRST

1536 TD01

RST

500mV

1536 TD03

SLEW RATE

≤0.1V/µs

RST

300mV

1536 TD04

FALL TIME

RST

3.3V

Power-Fail Detect

Operation

The LTC1536 is a low power, high accuracy triple supply

monitoring circuit. This reset generator has two basic

functions: generation of a reset when power supplies are

out of range, and generation of a reset or “soft” reset when

the reset button is pushed. The LTC1536 has the added

feature that when the reset supplies are grossly undervolt-

age there is a very short delay from undervoltage detect to

assertion of RST.

Supply Monitoring

olds for 200ms before the reset output is released. The

LTC1536 will assert reset during power-up, power-down

inputs.

drive circuits for the RST pin. This ensures that RST will

inputs rise above their thresholds, an internal timer is

started and RST is released after 200ms. RST outputs the

inverted state of what is seen on RST.

drops below its predetermined threshold and remains

their thresholds.

its threshold, RST is held at a logic low. A logic low of 0.4V

Pushbutton Reset

The LTC1536 provides a pushbutton reset input pin. The

If the PBR pin is not used it can be left floating.