RT8077GQW Richtek

RT8077 2A, 2MHz, Synchronous Step-Down Converter General Description Features zz z zz High Efficiency : Up to 95% The RT8077 is a high efficiency synchronous, step-down zz z zz Low R Internal Switches : 90m DS(ON) DC/DC converter. Its input voltage range is from 2.6V to zz z zz Programmable Frequency : 300kHz to 2MHz 5.5V and provides an adjustable regulated output voltage zz z zz No Schottky Diode Required from 0.8V to 5V, while delivering up to 2A of output current. zz z zz 0.8V Reference Allows for Low Output Voltage The internal synchronous low on-resistance power zz z zz Low Dropout Operation : 100% Duty Cycle switches increase efficiency and eliminate the need for zz z zz 2.6V to 5.5V Input Voltage Range an external Schottky diode. The switching frequency is zz z zz V Range from 0.8V to 5V OUT set by an external resistor or can be synchronized to an zz z zz Up to 2A Output Current external clock. The 100% duty cycle provides low dropout zz z zz Thermal Shutdown operation extending battery life in portable systems. zz z zz RoHS Compliant and Halogen Free Current mode operation with external compensation allows the transient response to be optimized over a wide Applications range of loads and output capacitors. z Portable Instruments The 100% duty cycle in Low Dropout Operation further z Battery-Powered Equipment maximize battery life. z Notebook Computers The RT8077 is available in the WDFN-8L 2x2 package. z Distributed Power Systems z IP Phones z Digital Cameras z Dynamic Supply Bias for GSM/EDGE PAs and 3G/4G PAs Simplified Application Circuit C COMP R COMP V PVDD IN COMP C IN RT8077 R2 FB R C R1 OSC F RT PGND L1 LX V OUT GND EN EN C OUT Copyright 2013 Richtek Technology Corporation. All rights reserved. is a registered trademark of Richtek Technology Corporation. DS8077-01 September 2013 www.richtek.com 1RT8077 Ordering Information Marking Information RT8077 0B : Product Code Package Type W : Date Code 0BW QW : WDFN-8L 2x2 (W-Type) Lead Plating System G : Green (Halogen Free and Pb Free) Note : Pin Configurations Richtek products are : (TOP VIEW) RoHS compliant and compatible with the current require- ments of IPC/JEDEC J-STD-020. RT 1 8 COMP GND 2 7 FB Suitable for use in SnPb or Pb-free soldering processes. 3 6 LX EN 4 9 5 PVDD PGND WDFN-8L 2x2 Functional Pin Description Pin No. Pin Name Pin Function Switching Frequency Setting. Connecting a resistor to ground from this pin sets 1 RT the switching frequency. 2, Signal Ground. All small-signal components and compensation components GND 9 (Exposed Pad) should be connected to this ground, which in turn connects to PGND at one point. 3 LX Switch Node. Connect this pin to the inductor. 4 PGND Power Ground. Connect this pin close to the negative terminal of C and C . IN OUT 5 PVDD Power Input. Decouple this pin to PGND with a capacitor. Enable Control Input. A logic-high (1.2V < EN < 5.5V) enables the converter 6 EN logic-low forces the IC into shutdown mode. Feedback Voltage Input. This pin receives the feedback voltage from a resistive 7 FB divider connected across the output. Compensation Node. The current comparator threshold increases with this control 8 COMP voltage. Connect external compensation elements to this pin to stabilize the control loop. Copyright 2013 Richtek Technology Corporation. All rights reserved. is a registered trademark of Richtek Technology Corporation. www.richtek.com DS8077-01 September 2013 2 GND