LTC1536 View Datasheet(PDF) - Linear Technology
Part Name
Description
MFG CO.
'LTC1536' PDF : 12 Pages View PDF
LTC1536
Precision Triple Supply Monitor
for PCI Applications
FEATURES
■ Simultaneously Monitors 5V, 3.3V and
Adjustable Inputs
■ Guaranteed Threshold Accuracy: ±0.75%
■ Low Supply Current: 100µA
■ Internal Reset Time Delay: 200ms
■ Manual Pushbutton Reset Input
■ Active Low and Active High Reset Outputs
■ Active Low “Soft” Reset Output
■ Power Supply Glitch Immunity
■ Guaranteed Reset for Either VCC3 ≥ 1V or VCC5 ≥ 1V
■ Meets PCI tFAIL Timing Specifications Rev 2.1
■ 8-Pin SO and MSOP Packages
U
APPLICATIO S
■ PCI-Based Systems
■ Desktop Computers
■ Notebook Computers
■ Intelligent Instruments
■ Portable Battery-Powered Equipment
■ Network Servers
DESCRIPTIO
The LTC®1536 is designed for PCI local bus applications
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
of meeting the PCI tFAIL timing specification. Tight 0.75%
threshold accuracy and glitch immunity ensure reliable
reset operation without false triggering.
The RST output is guaranteed to be in the correct state for
VCC5 or VCC3 down to 1V. The 100µA typical supply current
makes the LTC1536 ideal for power-conscious systems.
A manual pushbutton reset input provides the ability to
generate a very narrow “soft” reset pulse (100µs 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.
, LTC and LT are registered trademarks of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
TYPICAL APPLICATIO
Motherboard PCI RST Generation
3.3V ± 0.3V
5V ± 5%
PWR GOOD
0.1µF
0.1µF
LTC1536
PUSHBUTTON
RESET
RPU
1
8
VCC3 PBR
2
7
VCC5 SRST
3
6
RST
VCCA RST
4
5
GND RST
RPU SELECTED TO MEET RISE TIME
SLEW RATE REQUIREMENTS (1k MIN)
PCI
LOCAL
BUS
1536 TA01
Power Fail Waveform
5V Dropping Below 3.3V by 300mV
VCC5 = 5V TO 3V STEP
VCC3 = VCCA = 3.3V
4.7k PULL-UP FROM
5
RST TO VCC3
4
VCC5
3
2
RST
1
0
TIME (20ns/DIV)
1536 TA02
1536fa
1
Share Link: 
