Diodes Incorporated has introduced a battery protection device specifically for the safe operation of 1-cell lithium-ion (Li +) battery packs.
The AP9211 combines a protection chip with dual N-channel MOSFETs to provide a rich feature set, including overcharge, overdischarge and load short-circuit detection. The 1-cell battery pack for smartphones and mobile power supplies is the main end market. The target users of this protection circuit are circuit module manufacturers that provide protection to battery pack manufacturers.
The AP9211 packs a battery protection chip and a standard dual N-channel common-drain MOSFET in a small 3mm x 2mm 6-pin package. The low profile (<0.6mm) of the U-DFN2030-6 package helps enable thinner protective circuit board designs, which can provide greater battery capacity for a given battery size. By continuously monitoring the voltage and current, the chip can quickly turn off the MOSFET to prevent overcharging or overdischarging, including shorting the load.
Another advantage of AP9211 is the use of high voltage (up to 30V) CMOS process that can withstand surge voltage. This process can also achieve high-precision voltage detection with stable temperature coefficient performance. The device has a low quiescent operating current, typically 3.0 μA in normal mode and 0.1 μA maximum in power-down mode, thereby achieving power savings. The company said that another feature is the built-in fixed delay time, which reduces the need for external components.
