4-Pin uP Voltage Monitors
|Total Page||8 Pages|
|Features||Datasheet pdf 19-1122; Rev 1; 12/99 4-Pin µP Voltage Monitors with Pin-Selectable Power-On Reset Timeout Delay General Description The MAX821/MAX822 microprocessor (µP) supervisory circuits monitor power sup plies in µP and digital systems. They provide excellent circuit reliability a nd low cost by eliminating external com ponents and adjustments when used with 5V-powered or 3V-powered circuits. The MAX821/MAX822 also provide a power-on r eset timeout delay that is pin selectab le to 1ms (max), 20ms (min), or 100ms ( min). These devices perform a single fu nction: they assert a reset signal when ever the V CC supply voltage falls belo w a preset threshold, and they keep res et asserted for the pin-selected reset .|
|Keywords||MAX821, datasheet, pdf, Maxim, 4-Pin, uP, Voltage, Monitors, stock, pinout, distributor, price, schematic, inventory, databook, Electronic, Components, Parameters, parts, cross reference, chip, Semiconductor, circuit, Electric, manual, substitute, Equivalent|
19-1122; Rev 1; 12/99
4-Pin µP Voltage Monitors with Pin-Selectable
Power-On Reset Timeout Delay
The MAX821/MAX822 microprocessor (µP) supervisory
circuits monitor power supplies in µP and digital sys-
tems. They provide excellent circuit reliability and low
cost by eliminating external components and adjust-
ments when used with 5V-powered or 3V-powered cir-
cuits. The MAX821/MAX822 also provide a power-on
reset timeout delay that is pin selectable to 1ms (max),
20ms (min), or 100ms (min).
These devices perform a single function: they assert a
reset signal whenever the VCC supply voltage falls
below a preset threshold, and they keep reset asserted
for the pin-selected reset timeout delay after VCC has
risen above the reset threshold. The only difference
between the two devices is that the MAX821 has an
active-low RESET output (which is guaranteed to be in
the correct state for VCC down to 1V), while the
MAX822 has an active-high RESET output. The reset
comparator is designed to ignore fast transients on
VCC. Reset thresholds suitable for operation with a vari-
ety of supply voltages are available.
Low supply current makes the MAX821/MAX822 ideal
for use in portable equipment. These devices come in a
4-pin SOT143 package.
Critical µP and µC Power Monitoring
__________Typical Operating Circuit
o Pin-Selectable, Precision Power-On Reset Delay:
1ms (max), 20ms (min), or 100ms (min)
o Precision Monitoring of +3V to +5V Power-Supply
o 2.5µA Supply Current
o Guaranteed Over Temperature (-40°C to +125°C)
o Guaranteed RESET Valid to VCC = 1V (MAX821)
o Power-Supply Transient Immunity
o No External Components
o SOT143 Package
NOMINAL VTH (V)
* The first two letters in the package top mark identify the part,
while the remaining two letters are the lot-tracking code.
Note: These parts are offered in the SOT143-4 package, in the
extended temperature range (-40°C to +85°C).
( ) ARE FOR MAX822
(RESET) RESET 2
( ) ARE FOR MAX822
________________________________________________________________ Maxim Integrated Products 1
For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800.
For small orders, phone 1-800-835-8769.