GENERAL DESCRIPTION
The RT6321 supports low power mode (LPM) to dynamically change output voltage between target voltage and zero voltage. The RT6321 adopts Advanced Constant On-Time (ACOT® ) control architecture that provides ultra-fast transient response and further reduces the external component count. In steady states, the ACOT® operates at nearly constant switching frequency over line, load and output voltage ranges and makes the EMI filter design easier. By setting the voltage of the EN/MODE pin, RT6321 operates either in diode emulation mode (DEM) or ultrasonic mode (USM) at light load. The USM maintains operation frequency above 25kHz, which eliminates the acoustic noise. In the DEM, RT6321 provides the best light-load efficiency and improves the acoustic noise with spread spectrum function. RT6321 provides PGOOD indicator for easy system sequence control. Full protection features are also integrated in the device, including the cycle-by-cycle current limit, OVP, UVP, input UVLO and OTP.
Richtek Technology
