RT2652 2A, 1.2MHz Synchronous Step-Down Converter General Description Features High Efficiency : Up to 95% The RT2652 is a high efficiency synchronous, step-down Fixed Frequency : 1.2MHz DC/DC converter. The available input voltage range is from No Schottky Diode Required 2.7V to 5.5V the regulated output voltage is adjustable Internal Compensation from 0.6V to VIN while delivering up to 2A of output current. 0.6V Reference Allows Low Output Voltage The internal synchronous low on-resistance power 100% Duty Cycle for Low Dropout Operation switches increase efficiency and eliminate the need for OCP, UVP, OTP an external Schottky diode. The switching frequency is RoHS Compliant and Halogen Free fixed internally at 1.2MHz. The 100% duty cycle provides low dropout operation extending battery life in portable Applications systems. Current mode operation with internal Enterprise Servers compensation allows the transient response to be Ethernet Switches & Routers optimized. The RT2652 is available in the WDFN-10L 3x3 Global Storage package. Telecom & Industrial Cell Phones & DSC s Ordering Information RT2652 Pin Configurations (TOP VIEW) Package Type QW : WDFN-10L 3x3 (W-Type) 10 EN 1 PGND 9 VIN 2 PGND Lead Plating System 3 VIN 8 LX G : Green (Halogen Free and Pb Free) 4 7 LX AGND 5 11 6 FB AGND Note : WDFN-10L 3x3 Richtek products are : RoHS compliant and compatible with the current require- ments of IPC/JEDEC J-STD-020. Marking Information 0K= : Product Code Suitable for use in SnPb or Pb-free soldering processes. YMDNN : Date Code 0K=YM DNN Simplified Application Circuit RT2652 V IN VIN LX V OUT FB EN PGND AGND Copyright 2015 Richtek Technology Corporation. All rights reserved. is a registered trademark of Richtek Technology Corporation. DS2652-02 October 2015 www.richtek.com 1 PGNDRT2652 Functional Pin Description Pin No. Pin Name Pin Function 1 EN Enable Control Input. Pull high to turn on. Do not float. 2, 3 VIN Power Input. Decouple this pin to GND with a 22F ceramic capacitor at least. 4, 6 AGND Analog Ground. Feedback Voltage Input. This pin receives the feedback voltage from an external 5 FB resistive divider connected across the output. 7, 8 LX Power MOSFET Switch Node. Connect this pin to the inductor. 9, 10, Power Ground. The exposed pad must be soldered to a large PCB and PGND 11 (Exposed Pad) connected to GND for maximum power dissipation. Function Block Diagram VIN EN EN POR ISEN Slope OSC Comp. 0.6V Output EA Clamp FB OC Limit SS Driver LX 0.2V Control Logic UV NISEN PGND AGND OTP N-MOSFET Limit Operation The RT2652 is a monolithic, constant-frequency, current high side MOSFET turns off, the synchronous power mode step-down DC/DC converter. During normal switch (N-MOSFET) turns on until either the bottom current operation, the internal high side MOSFET is turned on at limit is reached or the beginning of the next cycle. The the beginning of each cycle. Current in the inductor operating frequency is set by the internal oscillator at increases until the peak inductor current reaches the value 1.2MHz. In VIN larger than 6V condition, the high side defined by the internal error amplifier. The error amplifier MOSFET is turned off and the low side MOSFET is adjusts the voltage of its output by comparing the feedback switched on until either the VIN over voltage condition is signal from a resistor divider on the FB pin with an internal cleared or the low side MOSFET s current limit is reached. 0.6V reference. When the load current increases, it causes a reduction in the feedback voltage relative to the reference. The error amplifier raises its output voltage until the average inductor current matches the new load current. When the Copyright 2015 Richtek Technology Corporation. All rights reserved. is a registered trademark of Richtek Technology Corporation. www.richtek.com DS2652-02 October 2015 2