Supervisor IC with battery switchover — 4.65V threshold, 8-PDIP
The MAX817LEPA is a battery-backup supervisor IC from Maxim Integrated, monitoring a single 4.65V threshold rail with an active-low, open-drain reset output.
140ms reset timeout — what it means for the board
The 140ms minimum reset timeout holds the processor in reset for long enough after the supply crosses the 4.65V threshold to let the rail stabilise — critical for avoiding brown-out boot failures on microcontrollers that need a settled Vcc before the oscillator starts. The open-drain output lets multiple supervisors share a common pull-up resistor, or wire-OR with another reset source, without contention — a common topology on multi-rail boards where the FPGA and MCU reset chains converge.
Active production — RoHS non-compliant
Note the RoHS non-compliant marking — this part uses lead-bearing solder (tin-lead) on the leads, which is acceptable in military, aerospace, and certain industrial applications that have a RoHS exemption, but it will not pass a standard RoHS inspection.