四通道数字PWM降压控制器XRP7708and XRP7740

　　The XRP7708 and XRP7740 are quad-output pulse-width modulated （PWM） step-down DCDC controllers with a built-in LDO for standby power and GPIOs. The devices provide a complete power management solution in one IC and are fully programmable via an I 2 C serial interface. Independent Digital Pulse Width Modulator （DPWM） channels regulate output voltages and provide all required protection functions such as current limiting and over-voltage protection. Each output voltage can be programmed from 0.9V to 5.1V without the need of an external voltage divider. The wide range of the programmable DPWM switching frequency （from 300 KHz to 1.5 MHz） enables the user to optimize between efficiency and component size. Input voltage range is from 6.5V to 20V. An I 2 C bus interface is provided to program the IC as well as to communicate with the host for fault reporting and handling， power rail parameters monitoring， etc. The device offers a complete solution for softstart and soft-stop. The start-up delay and ramp of each PWM regulator can be independently controlled. The device can start up a pre-biased PWM channel without causing large negative inductor current.