The XR77103 features three synchronous, wide input range, high efficiency buck converters. Each converter is digitally programmable requiring minimal external components thus providing the smallest size solution possible.
The converters can operate in 5V, 9V and 12V systems and have integrated power switches. The output voltage of each converter can be adjusted by programming the values in the VOUT setting registers through an I2C interface. The adjustable range is 0.8~6V with 50mV resolution. The output voltage can also be set externally using an external resistor divider. Output sequence among the outputs, soft-start time and the peak inductor current limit are also set through I2C.
The switching frequency of the converters can either be set with I2C or can be synchronized to an external clock. The switching regulators are designed to operate from 300kHz to 2.2MHz. Each converter operates in phase or out of phase according to the value in the phase setting register. This can minimize the input filter requirements.
XR77103 features a supervisor circuit that monitors each converter output. PGOOD pin is asserted once sequencing is done, all outputs are reported in regulation and the reset timer expires. The polarity of the signal is active high.
XR77103 also features a light load Pulse Skipping Mode (PSM). It is set through I2C. The PSM mode allows for a reduction on the input power supplied to the system when the host processor is in stand-by mode (low activity) mode.