General Description
The RT8249A/B/C is a dual-channel step-down, controller
generating supply voltages for battery-powered systems.
It includes two Pulse-Width Modulation (PWM) controllers
adjustable from 2V to 5.5V, and two fixed 5V/3.3V linear
regulators. Each linear regulator provides up to 100mA
output current and 3.3V linear regulator provides 1%
accuracy under 35mA. The RT8249A/B has an oscillator
output to driver the external charge pump application. The
RT8249C provides a mode selection pin, SKIPSEL, to
select Diode-Emulation Mode (DEM) or Audio Skipping
Mode (ASM). Other features include on-board power-up
sequencing, a power-good output, internal soft-start, and
soft-discharge output that prevents negative voltage during
shutdown.
A constant current ripple PWM control scheme operates
without sense resistors and provides 100ns response to
load transient. For maximizing power efficiency, the
RT8249A/B/C automatically switches to the diodeemulation
mode in light load applications. The RT8249A/
B/C is available in the WQFN-20L 3x3 package.

Features
 Support Connected Standby Mode for Ultrabook
 CCRCOT Control with 100ns Load Step Response
 PWM Maximum Duty Ratio > 98%
 5V to 25V Input Voltage Range
 2V to 5.5V Output Voltage Range
 5V/3.3V LDOs with 100mA Output Current
 1% Accuracy on 3.3V LDO Output
 Oscillator Driving Output for Charge Pump
Application
 Internal Frequency Setting
 RT8249A/B : 400kHz/475kHz (CH1/CH2)
 RT8249C : 500kHz/600kHz (CH1/CH2)
 Internal Soft-Start and Soft-Discharge
 4700ppm/°C RDS(ON) Current Sensing
 Independent Switcher Enable Control
 Built in OVP/UVP/OCP/OTP
 Non-latch UVLO
 Power Good Indicator
 20-Lead WQFN Package
 RoHS Compliant and Halogen Free