MAX1870AETJ+

The MAX1870AETJ+ from Analog Devices is a versatile multichemistry battery charger designed for charging lithium-ion, NiCd, or NiMH batteries. It features a proprietary step-up/step-down control scheme, enabling efficient charging with battery voltages both above and below the adapter voltage. This highly integrated solution requires minimal external components.

The device accurately charges two to four Li+ series cells at greater than 4A. It includes a programmable input current limit to prevent AC adapter overload when simultaneously supplying the load and charger. The MAX1870AETJ+ provides analog outputs for monitoring adapter and charge current, and a digital output indicates AC adapter presence. When the adapter is removed, it consumes less than 1µA from the battery.

Key electrical specifications include an input voltage range of 8V to 28V and a battery voltage range of 0V to 17.6V. It boasts ±0.5% charge-voltage accuracy, ±9% charge-current accuracy, and ±8% input current-limit accuracy. The charger is programmable for maximum battery charge current, charge voltage, and input-current limit.

Packaged in a 32-pin thin QFN (5mm x 5mm) with surface mount capability, the MAX1870AETJ+ is specified for an extended operating temperature range of -40°C to +85°C. This compact package saves space while supporting both step-up and step-down operations, making it suitable for applications like notebook and handheld terminals.