Low-Dropout Regulator Controls Single-Cell Li-Ion Batteries

In the TK73241MCLH and TK73242MCLH low-dropout regulator ICs, an external PNP transistor is used to provide either a continuous or pulsed output current level from 100 mA to 5A. The devices feature a total voltage accuracy of ±0.8% and are equipped with an internal reverse bias current that reduces battery drain to 2 nA typical when not charging. Other features include internal short-circuit protection and a CMOS/TTL-compatible on/off switch.The ICs’ internal electronic switch can be controlled by TTL or CMOS lotic levels. The devices are in the “on” state when the control pin is pulled to a high logic level. A pin for a bypass capacitor, which connects to the internal circuitry, is provided to lower the overall output noise level. Typical applications for the ICs include use as a single-cell lithium-ion battery chargers in digital cameras, portable stereo equipment, cellular phones, and more.