1

LTC1536

Precision Triple Supply Monitor

for PCI Applications

1

2

3

4

8

7

6

5

GND

PBR

SRST

RST

RST

LTC1536

PUSHBUTTON

RESET

PCI

LOCAL

BUS

SLEW RATE REQUIREMENTS (1k MIN)

5V

±5%

3.3V

±0.3V

0.1

µF

RST

1536 TA01

PWR GOOD

0.1

µF

Motherboard PCI RST Generation

TIME (20ns/DIV)

5

4

3

2

1

0

1536 TA02

4.7k PULL-UP FROM

RST

Power Fail Waveform

5V Dropping Below 3.3V by 300mV

s

Simultaneously Monitors 5V, 3.3V and

Adjustable Inputs

s

Guaranteed Threshold Accuracy:

±0.75%

s

Low Supply Current: 100

µA

s

Internal Reset Time Delay: 200ms

s

Manual Pushbutton Reset Input

s

Active Low and Active High Reset Outputs

s

Active Low “Soft” Reset Output

s

Power Supply Glitch Immunity

s

s

s

8-Pin SO and MSOP Packages

The LTC

with multiple supply voltages that require low power,

small size, high speed and high accuracy supply

monitoring.

For 3.3V and 5V supplies that are > 500mV below spec or

for the condition when the 5V supply falls below the 3.3V

supply, the LTC1536 has a very fast response time capable

threshold accuracy and glitch immunity ensure reliable

reset operation without false triggering.

The RST output is guaranteed to be in the correct state for

makes the LTC1536 ideal for power-conscious systems.

A manual pushbutton reset input provides the ability to

generate a very narrow “soft” reset pulse (100

µs typ) or a

200ms reset pulse equivalent to a power-on reset. Both

SRST and RST outputs are open-drain and can be OR-tied

with other reset sources.

s

PCI-Based Systems

s

Desktop Computers

s

Notebook Computers

s

Intelligent Instruments

s

Portable Battery-Powered Equipment

s

Network Servers

, LTC and LT are registered trademarks of Linear Technology Corporation.

DESCRIPTIO

FEATURES

APPLICATIO S

TYPICAL APPLICATIO