View max6439-max6442 datasheet:

19-2535; Rev 0; 7/02 Low-Power, Single-/Dual-Level Battery Monitors with Hysteresis and Integrated µP Reset General Description Features The MAX6439–MAX6442 are a family of ultra-low-power Factory-Trimmed VBATT Threshold Options for battery monitors with integrated microprocessor (µP) Monitoring Single-Cell Li+ or Multicell supervisors. The battery monitors are offered with sin- Alkaline/NiCd/NiMH Applications gle or dual low-battery output options that can be used Immune to Short Battery Voltage Transients to signal when the battery is OK (enabling full system operation), when the battery is low (for low-power sys- Low Current (2.5µA typ at 3.6V) tem operation), and when the battery is dead (to dis- Single and Dual Low-Battery Output Options able system operation). Th