4-Pin μP Voltage Monitors
with Manual Reset Input
The MAX811/MAX812 are low-power microprocessor
(µP) supervisory circuits used to monitor power sup-
plies in µP and digital systems. They provide excellent
circuit reliability and low cost by eliminating external
components and adjustments when used with 5V-
powered or 3V-powered circuits. The MAX811/MAX812
also provide a debounced manual reset input.
These devices perform a single function: They assert a
reset signal whenever the VCC supply voltage falls
below a preset threshold, keeping it asserted for at
least 140ms after VCC has risen above the reset thresh-
old. The only difference between the two devices is that
the MAX811 has an active-low RESET output (which is
guaranteed to be in the correct state for VCC down to
1V), while the MAX812 has an active-high RESET out-
put. The reset comparator is designed to ignore fast
transients on VCC. Reset thresholds are available for
operation with a variety of supply voltages.
Low supply current makes the MAX811/MAX812 ideal
for use in portable equipment. The devices come in a
4-pin SOT143 package.
Critical µP and µC Power Monitoring
Typical Operating Circuit
( ) ARE FOR MAX812
Benefits and Features
• Integrated Voltage Monitor Increases System
Robustness with Added Manual Reset
• Precision Monitoring of 3V, 3.3V, and 5V
• 140ms Min Power-On-Reset Pulse Width
- RESET Output (MAX811), RESET Output (MAX812)
• Guaranteed Over Temperature
• Guaranteed RESET Valid to VCC = 1V (MAX811)
• Power-Supply Transient Immunity
• Saves Board Space
• No External Components
• 4-Pin SOT143 Package
• Low Power Consumption Simplifies Power-Supply
• 6µA Supply Current
TEMP RANGE PIN-PACKAGE
MAX811_EUS-T -40°C to +85°C 4 SOT143
MAX812_EUS-T -40°C to +85°C 4 SOT143
*This part offers a choice of five different reset threshold voltages.
Select the letter corresponding to the desired nominal reset
threshold voltage, and insert it into the blank to complete the
Devices are available in both leaded and lead(Pb)-free packaging.
Specify lead-free by replacing “-T” with “+T” when ordering.
(RESET) RESET 2
( ) ARE FOR MAX812
NOTE: SEE PACKAGE INFORMATION FOR MARKING INFORMATION.
19-0411; Rev 5; 6/15