High Efficiency Dual-Channel Output Synchronous Buck PWM Controller with Phase Interleaving and Two LDO Regulators

The RT8127 is a high efficiency Dual-Channel output synchronous Buck PWM controller with integrated MOSFET drivers and two LDOs. This part features Green Voltage Mode (GVM^TM) control, which is specifically designed to improve efficiency at light load condition. At light load condition, the RT8127 is pin configurable to automatically operate in diode emulation mode with constant on-time PFM to reduce switching frequency so as to improve conversion efficiency. As the load current increases, the RT8127 leaves the diode emulation mode and operates in Continuous Conduction Mode (CCM) with fixed-frequency, 180° out of phase interleaved PWM to reduce input capacitance. The RT8127 supports 4.5V to 26V input voltage range and has integrated 5V LDO which supplies the internal gate drivers as well as the controller. When channel 1 Buck regulator output voltage is higher than 5V, the supply voltage will be automatically switched to the Buck regulator output from the integrated 5V LDO. The RT8127 supports enable/disable function for each channel and also features external soft-start, adjustable switching frequency and power good indication. This device utilizes lossless inductor DCR current sensing for over current protection. Other protections include over voltage, under voltage, thermal shutdown and under voltage lockout. The RT8127 is available in a WQFN-28L 4x4 small footprint package.