Features

• Complete Low Power Wireless NiMH Charger
• Low Minimum Input Voltage: 2.2V
• Small Total Solution Volume
• 1.5V, 25mA Linear Single-Cell NiMH Charger
• Temperature Compensated Charge Voltage
• Integrated Rectifier with Overvoltage Limit
• Zinc-Air Battery Detection
• Reverse Polarity Protection
• Thermally Enhanced 6-Lead (2mm × 2mm) DFN package

Typical Application

Description

The LTC®4123 is a low power wireless receiver and a constant-current/constant-voltage linear charger for NiMH batteries. An external programming resistor sets the charge current up to 25mA. The temperature compensated charge voltage feature protects the NiMH battery and prevents overcharging.

Wireless charging with the LTC4123 allows products to be charged while sealed within enclosures and eliminates bulky connectors in space constrained environments. The LTC4123 also makes it possible to charge NiMH batteries used in moving or rotating equipment.

The LTC4123 prevents charging of Zinc-Air batteries as well as batteries inserted with reverse polarity. The LTC4123 pauses charging if its temperature is too hot or too cold. An internal timer provides time-based charging termination.

The 2mm × 2mm DFN package and low external component count make the LTC4123 well-suited for hearing aid applications or other low power portable devices where small solution size is mandatory.