RN5T568 Multi-Channel PMU IC

Nisshinbo Micro Devices' RN5T568 multi-channel PMU IC is a single-chip solution and provides four high-efficiency step-down DC/DC converters, seven low-dropout regulators, four GPIOs, an interrupt controller (INTC), and an I²C-bus interface. The output voltages and the power on/off sequence settings can be tailored in a profile and saved in a built-in one-time programmable (OTP) memory.

The RN5T568 includes custom programmable features by OTP for initial output voltage setting and start-up/shut-down sequencing. A 2-wire I²C bus interface operating at 400 kHz or 3.4 MHz provides additional control by register settings such as turning individual output voltages on or off as well as adjusting the DC/DC converter and LDO output voltage levels by a dynamic voltage scaling (DVS) feature. Step-rate for adjusting voltages is 50 mV for OTP and 12.5 mV for register settings.

The RN5T569 distinguishes on, off, and sleep operating modes, the current consumption varies from a typical 15 µA in off-mode to a maximum 350 µA in on-mode depending on which outputs are enabled.

The four integrated buck DC/DC converters are able to provide 2x 2 A and 2x 3 A output current and have a peak efficiency level of 95%. All operate with a 1 µH inductor and 22 µF output capacitor.

Five LDO regulators can be used for multipurposes and provide 3x 300 mA and 2x 200 mA. They have a fast-transient response, low output voltage noise, and high ripple rejection ratio. Two additional LDOs are always on but can be configured as always off as well when not used. One powers an RTC with a coin battery as a back-up power supply and includes reverse current protection. The other LDO is used for other purposes.

Target applications are navigation systems, set-top boxes, and power supplies for application processors. The RN5T568 is available in a QFN0707-48 package. A reference circuit is available to simplify the design of the power supply as well as a bill of material with recommended components. To achieve maximum performance of the circuit, an example circuit board layout is available.