The MAX6427-MAX6438 are single/dual-level battery monitors with internal hysteresis. These devices are offered with single (MAX6427/MAX6428/MAX6429, MAX6433/ MAX6434/MAX6435) or dual (MAX6430/MAX6431/ MAX6432, MAX6436/MAX6437/MAX6438) low-battery output indicators, which can be used to indicate three battery conditions: battery is good (operate system in normal mode), battery is weak (operate system in low-power mode), or battery is empty (disable the system). These devices are ideal for monitoring single lithium-ion (Li+) cells or multicell alkaline/NiCd/NiMH power supplies. When the power-supply voltage drops below the specified low threshold, the low-battery output asserts. When the voltage rises above the specified high threshold, the low- battery output is deasserted following a 140ms minimum timeout period. The timeout period ensures that the supply voltages have stabilized before power-converter or micro- processor activity is enabled. The MAX6427–MAX6438 family is available with several monitoring options. The MAX6427/MAX6428/MAX6429 offer factory-trimmed battery-monitor thresholds, with a single low-battery output. The MAX6430/MAX6431/MAX6432 also feature factory-trimmed thresholds, but have two low- battery outputs. The MAX6433–MAX6438 have user-adjustable threshold voltages permitting the user to select the hysteresis range, and consequently the sensitivity of the system to noise. A wide hysteresis range also prevents chattering that can result in frequent power-converter or micro-controller switching.
The MAX6427‑MAX6438 family provides low‑power battery‑monitoring for single‑cell Li‑ion or multicell alkaline/NiCd/NiMH supplies. Devices offer either a single low‑battery output (MAX6427‑MAX6429, MAX6433‑MAX6435) or dual outputs (MAX6430‑MAX6432, MAX6436‑MAX6438) and include built‑in hysteresis to prevent chatter.
Features include factory‑trimmed threshold options, user‑adjustable thresholds with a 615 mV reference, multiple output configurations (push‑pull, open‑drain), and operation over a –40 °C to +85 °C temperature range. The ICs are supplied in small SOT23‑3, SOT23‑5, SOT23‑6 and SOT143‑4 packages.
| Output Current (all pins) | 0.20 mA |
|---|---|
| Operating Temperature Range | -40 °C to +85 °C |
| Package Types | SOT23‑3, SOT23‑5, SOT23‑6, SOT143‑4 |
| Factory‑Trimmed Low Thresholds | 1.6 V to 2.1 V (or 2.6 V to 3.1 V) |
| User‑Adjustable Threshold Reference | 615 mV internal reference |
The low‑battery output remains asserted for at least 140 ms after the voltage crosses the threshold.
The devices support push‑pull, open‑drain, and open‑drain LBO options for low‑battery outputs.
They are available in small SOT23 and SOT143 packages, including 3‑pin, 4‑pin, 5‑pin, and 6‑pin variants.