Battery-charger design: Li-Ion/Li-Polymer linear charge-management controllers

By Control Engineering Staff October 12, 2006

Microchip offers the MCP73833 Li-Ion battery charger evaluation board to support development using the MCP73833/4 charge-management controllers.

Microchip Technology announces single-cell, high current (1A) Li-Ion/Li-Polymer linear charge-management controllers. These combine several key features in a single chip for reliable charging of high-capacity Li-Ion and Li-Polymer batteries. Available in small MSOP and thermally efficient 3 mm x 3 mm DFN packages, the MCP73833 and MCP73834 chargers are said to enable smarter, faster and safer battery-charger designs.

Because they combine a pass transistor, current-sense, and reverse-discharge protection on a single chip, the MCP73833/4 charge-management controllers reportedly eliminate the need for external components and enable smaller, more integrated charging solutions. The controllers include multiple combinations of key charging parameters, including pre-conditioning current threshold and ratio, charge-termination threshold and recharge threshold ratio. With high charging currents of up to 1A and support for multiple regulated output voltages (4.2V, 4.35V, 4.4V and 4.5V), the devices can be used with early generation batteries where output voltages are lower and with newer batteries where output voltages are higher.

Safety features include charge timers, battery-temperature feedback, and thermal-current regulation. Device-specific features include a power-good output on the MCP73833 and a timer-enable input on the MCP73834. The timer-enable input can disable the timer when the battery is charged at the same time that current is supplied to the system. Both devices offer a low dropout regulator (LDO) test mode that enables application system test even in the absence of a battery.

To support development using the MCP73833/4 charge-management controllers, Microchip offers the MCP73833 Li-Ion Battery Charger Evaluation Board ( Part # MCP73833EV ) for $20 from www.microchipdirect.com. Click here for sampling.