MAX823 Datasheet, PDF (1/14 Pages) Maxim Integrated Products – 5-Pin Microprocessor Supervisory Circuits

MAX823/4/5
Voltage Supervisor with Watchdog Timer
and Manual Reset
Revision 1.0
General Description
The MAX823/4/5 voltage supervisory circuits combine
low-current, manual reset input, watchdog timer, active-
high and active-low push-pull outputs. The reset outputs
are asserted and held when the supply voltage falls below
the factory-programmed threshold voltage, when the /MR
pin is pulled low, or if the watchdog times out. Reset is
asserted for the reset timeout delay after the supply
voltage increases above the rising threshold voltage or
when manual reset input is asserted high.
The MAX823/4/5 features an integrated pull-up resistor on
the /MR pin. An active-low push-pull reset output (/RESET)
and an active-high reset output (RESET) provide flexibility
when interfacing with various microcontrollers, PMICs, or
load switches. The watchdog input can be left
unconnected for applications that do not require watchdog
monitoring.
The MAX823/4/5 consumes a quiescent current of only
3.8µA and is offered in standard SOT23-5 and SC70-5
packages. It is rated for the –40°C to +125°C temperature
range.
Datasheets and support documentation are available on
Micrel’s web site at: www.micrel.com.
Features
 Precision 1.665V to 4.625V power supply monitor
 ±0.5% threshold accuracy at TA = +25°C
 ±1.5% threshold accuracy from TA = –40°C to +125°C
 3.8µA supply current (S,R,T,W,Y,Z options)
 4.8µA supply current (L,M options)
 Manual reset input (MAX823/5)
 140ms (min.) reset timeout period
 1.6s (typ.) watchdog timeout period
 Active-high and active-low push-pull outputs
 Guaranteed reset output valid to VCC = 1V
 40°C to +125°C junction temperature range
 5-pin SOT23 & SC70 packages
 8x lower watchdog input current than competition
Applications
 Computers and Controllers
 Embedded Controllers
 Intelligent Instruments
 Automotive Systems
 Critical µP Monitoring
 Portable/ Battery-Powered Equipment
Typical Application
Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel [phone] • fax + 1 [phone] • http://www.micrel.com
January 14, 2014
Revision 1.0