Holtek announce the release of its new power bank dedicated MCU, the BP45F4MB, which provides full support for all the required power bank functions. The device includes single lithium battery charging, discharging and power indicator functions. The internal OVP and OCP circuits can implement over voltage and over current protection during battery charging and discharging.
The complementary PWM outputs can directly drive external PMOS and NMOS transistors thus allowing it to implement synchronous rectifier boost or buck functions. With a conversion efficiency of up to 94%, these features combine to make the device extremely suitable for single lithium battery power bank applications.
The internal 2.4V reference voltage, which has a tolerance of ±1%, is used as a reference voltage source for the A/D Converter as well as the over voltage and over current protection circuits. The device includes a resistance divider which permits the A/D Converter to detect the battery voltage as well as the input/output voltage. The device also provides pull-high and pull-low resistors for the PMOS and NMOS transistors to reduce the number of required external component thus reducing the PCB size.
With regard to other internal functions, the device includes a Flash program memory of 2K×16, a data memory of 128×8, an operating voltage of 2.5V~5.5V, up to 18 multi-function I/O pins, an integrated 30MHz high frequency RC oscillator, a 32kHz low frequency RC oscillator, a 7 external channel 12-bit resolution A/D Converter, a single 10-bit PTM and a single 16-bit STM. As for packaging, the device is supplied in both 16-pin NSOP and 20-pin SSOP package types.
