LTC699 Datasheet, PDF (1/4 Pages) Linear Technology – Microprocessor Supervisory Circuit

FEATURES
s _{Guaranteed Reset Assertion at VCC = 1V}
s _{1.5mA Maximum Supply Current}
s _{SO-8 Packaging}
s _{4.65V Precision Voltage Monitor}
s _{Power OK/Reset Time Delay: 200ms}
s _{Minimum External Component Count}
s _{Performance Specified Over Temperature}
s _{Superior Upgrade for MAX699}
APPLICATI S
s _{Critical µP Power Monitoring}
s _{Intelligent Instruments}
s _{Computers and Controllers}
s _{Automotive Systems}
LTC699
Microprocessor
Supervisory Circuit
DESCRIPTIO
The LTC699 provides power supply monitoring for
microprocessor-based systems. The features include mi-
croprocessor reset and watchdog timing. Precise internal
voltage reference and comparator circuit monitor the
power supply line. When an out-of-tolerance condition
occurs, the RESET output is forced to active low. In
addition, the RESET output is guaranteed to remain logic
low even with V_CC as low as 1V.
An internal watchdog timer is also available, which forces
the RESET output to active low when the watchdog input
is not toggled prior to the time-out period of 1.6 seconds.
The LTC699 is offered in DIP and surface mount packages.
TYPICAL APPLICATI
BLOCK DIAGRA
+5V
V_CC
RESET
500k
LTC699
0.1µF
WDI
GND
VCC
µP POWER
µP RESET
µP
SYSTEM
I/O LINE
0.1µF
+
C1
–
1.3V
OSC
RESET PULSE
GENERATOR
WATCHDOG
TIMER
LTC699 TA1
WDI
MICROPROCESSOR RESET AND WATCHDOG TIMING IN
A SINGLE CHIP FOR MICROPROCESSOR SYSTEMS.
TRANSITION
DETECTOR
RESET
GND
LTC699 BD
1