Datasheet Maxim MAX6849

19-2947; Rev 1; 11/05 Low-Power, Adjustable Battery Monitors with
Hysteresis and Integrated µP Reset
The MAX6846–MAX6849 are a family of ultra-low-power
battery monitors with integrated microprocessor (µP)
supervisors. The user-adjustable battery monitors are
offered with single or dual low-battery output options that
can be used to signal when the battery is OK (enabling
full system operation), when the battery is low (for lowpower system operation), and when the battery is dead
(to disable system operation). These devices also have
an independent µP supervisor that monitors VCC and
provides an active-low reset output. A manual reset
function is available to reset the µP with a pushbutton.
The MAX6846–MAX6849 are ideal for single-cell lithiumion (Li+) or multicell alkaline/NiCd/NiMH applications.
When the battery voltage drops below each adjusted low
threshold, the low-battery outputs are asserted to alert
the system. When the voltage rises above the adjusted
high thresholds, the outputs are deasserted after a
150ms minimum timeout period, ensuring the voltages
have stabilized before power circuitry is activated or providing microprocessor reset timing.
These devices have user-adjustable battery threshold
voltages, providing a wide hysteresis range to prevent
chattering that can result due to battery recovery after
load removal. Single low-battery outputs are supplied …