RT5021

® RT5021 6 + 3 Channels DC/DC PMU with Li-ion Battery Charger for CMOS DSC/DV General Description The RT5021 is a complete power supply solution for digital still cameras and other hand held devices. The RT5021 is composed of a multi-channel DC/DC power converter unit, a single-cell linear Li-ion battery charger, a charger type detector, and an I2C control interface. The power converter unit includes one synchronous stepup converter (CH1), one synchronous step-up/down converter (CH2), three synchronous step-down converters (CH3/4/5), two LDOs with input power as low as 1.5V (CH6/8), one WLED driver in synchronous high-voltage step-up mode or low-voltage current regulator mode (CH7), and a keep-alive LDO (CH9) for RTC application. All converters are internally frequency compensated and integrate power MOSFETs. The power converter unit provides complete protection functions : over current, thermal shutdown, over voltage, and under voltage protection. RT5021 has a WAKEUP impulse generation circuitry to monitor VIN or BAT installation event. To fulfill most of applications, RT5021 has six preset power on/off sequences. The battery charger includes Auto Power Path Management (APPM). No external MOSFETs are required. The charger can enter sleep mode when power is removed. Charging tasks are optimized by using a control algorithm to vary the charge rate, including pre-charge mode, fast charge mode and constant voltage mode. The charge current can also be programmed via the I2C co...