RT8071CGQW Evaluation Board your power partner. 3A, 1MHz, Synchronous Step-Down Converter Purpose The RT8071C is a high efficiency synchronous, step-down DC/DC converter. Its input voltage ranges from 2.7V to 5.5V that provides an adjustable regulated output voltage from 0.6V to VIN while delivering up to 3A of output current. This document explains the function and use of the RT8071C evaluation board (EVB), and provides information to enable operation, modification of the evaluation board and circuit to suit individual requirements. Table of Contents Purpose ................................................................................................................................................................. 1 Introduction............................................................................................................................................................ 2 Key Performance Summary Table .......................................................................................................................... 2 Bench Test Setup Conditions ................................................................................................................................. 3 Schematic, Bill of Materials & Board Layout ........................................................................................................... 5 More Information.................................................................................................................................................... 7 Important Notice for Richtek Evaluation Board ....................................................................................................... 7 EVB_RT8071CGQW-00 October 2015 1 http://www.richtek.com RT8071CGQW Evaluation Board your power partner. Introduction General Product Information The RT8071C is a high efficiency synchronous, step-down DC/DC converter. Its input voltage ranges from 2.7V to 5.5V that provides an adjustable regulated output voltage from 0.6V to VIN while delivering up to 3A of output current. The internal synchronous low On-resistance power switches increase efficiency and eliminate the need for an external Schottky diode. The switching frequency is fixed internally at 1MHz. The 100% duty cycle provides low dropout operation, hence extending battery life in portable systems. Current mode operation with internal compensation allows the transient response to be optimized over a wide range of loads and output capacitors. The RT8071C is available in a WDFN-10L 3x3 package. Product Feature High Efficiency : Up to 95% Low RDS(ON) Power Switches : 69mΩ/49mΩ Current Mode Operation Fast Transient Response Fixed Frequency : 1MHz No Schottky Diode Required Internal Compensation 0.6V Reference Allows Low Output Voltage Low Dropout Operation : 100% Duty Cycle OCP, UVP, OTP OpenVReg Type 0-LV Compliant Key Performance Summary Table Key Features Evaluation Board Number : PCB052_V1 Input Voltage Range 2.7V to 5.5V Max Output Current 3A Default Output Voltage 1.05V Default Marking & Package Type RT8071CGQW, WDFN-10L 3x3 Operation Frequency Steady 1MHz at all loads EVB_RT8071CGQW-00 October 2015 2 http://www.richtek.com RT8071CGQW Evaluation Board your power partner. Bench Test Setup Conditions Headers Description and Placement Please carefully inspect the EVB IC and external components, comparing them to the following Bill of Materials, to ensure that all components are installed and undamaged. If any components are missing or damaged during transportation, please contact the distributor or send e-mail to [email protected] Test Points The EVB is provided with the test points and pin names listed in the table below. Test point/ Pin name Signal Comment (expected waveforms or voltage levels on test points) FB Feedback voltage input Feedback Input. This pin receives the feedback voltage from a resistive voltage divider connected across the output. VCC Supply voltage input. Supply Voltage Input. Decouple this pin to GND with at least 1µF ceramic capacitor. VIN Input voltage Power input. Support 2.7V to 5.5V Input Voltage. Decouple this pin to GND with at least 10µF ceramic capacitor. GND Ground Ground. The exposed pad must be soldered to a large PCB and connected to GND for maximum power dissipation. SW Switch node test point Switch Node. Connect this pin to the inductor. NC No connection No Internal Connection. PGOOD Power good indicator Power Good Indicator. This pin is an open drain logic output. The PGOOD will be pulled to ground when the output voltage is less than 90% of the target output voltage. EN Enable test point Enable Control Input. Pull high the EN pin to turn on the converter. EVB_RT8071CGQW-00 October 2015 3 http://www.richtek.com RT8071CGQW Evaluation Board your power partner. Power-up & Measurement Procedure 1. Connect input power (2.7V < VIN < 5.5V) and input ground to VIN and GND test pins respectively. 2. Connect positive end and negative terminals of load to VOUT and GND test pins respectively. 3. There is a 3-pin header “EN” for enable control. To use a jumper at “H” option to tie EN test pin to input power VIN for enabling the device. Inversely, to use a jumper at “L” option to tie EN test pin and ground GND for disabling the device. 4. Verify the output voltage (approximately 1.05V) between VOUT and GND. 5. Connect an external load up to 3A to the VOUT and GND terminals and verify the output voltage and current. Output Voltage Setting Set the output voltage with the resistive divider (R3, R5) between VOUT and GND with the midpoint connected to FB. The output is set by the following formula : VOUT VFB x (1 R3 ) R5 EVB_RT8071CGQW-00 October 2015 4 http://www.richtek.com RT8071CGQW Evaluation Board your power partner. Schematic, Bill of Materials & Board Layout EVB Schematic Diagram PG TP1 SW TP2 U1 2 J1 + C2 0.1uF/0603 18k SIP-3P TP3 EN 2 8.2k/0603 GP5 1 Z5 Z6 1 1 FK_1 FK_1 GND VCC Z1 1 Z2 1 SIP-1P-M 2 R5 1 1VCC 680pF GP6 R7 Z3 1 SIP-1P-M GP4 C9 2 GND 1 1 1 C3 SW-2P C4 2 22uF/1210 2 22uF/1210 4 DFN-10L 3x3 C1 1 R3 680pF 2 FB 1 NC EC1 2 1 FB 2 EN/FS 1 1 2 3 1 2 3 VCC Vout 6.2K/0603 2 0.1uF/0603 2 1 JP1 2 10 EN GND_4 R4 2 VCC 0/0603 C8 1 1 1 C7 2 0.1uF/0603 1 2 10uF/1210 1 2 NC GP3 C5 0/0603 R6 7 1 SW_7 1.4uH SW 6 1 1 SW_6 GP2 VOUT 1 VIN 8 1 NC GND C6 Vout/3A L1 PGOOD 1 2 VIN 2 PG 9 R1 100K/0603 3 5 1 GND_5 1 VIN 1 1 GP1 1 Z4 1 SIP-1P-M GND SIP-1P-M Bill of Materials Reference Qty Part Number Description Package Manufacture U1 1 RT8071CGQW DC/DC Converter WDFN-10L 3x3 RICHTEK C1, C4 2 C3225X5R0J226M 22µF/25V/X5R 1210 TDK C5 1 C3225X5R0J106M 10µF/50V/X5R 1210 TDK C6 1 NC 1210 TDK C3, C9 1 0603B681K500NT 680pF/50V/X7R 0603 WALSIN C2, C7, C8 3 0603B104K500NT 0.1µF/50V/X7R 0603 WALSIN EC1 1 NC 1206 JACKSON L1 1 NR8040T1R4N 1.4µH R1 1 WR06X1003FT 100k 0603 WALSIN R3 1 WR06X6201FT 6.2k 0603 WALSIN R5 1 WR06X8201FT 8.2k 0603 WALSIN R4, R6 2 WR06X000PT 0 0603 WALSIN R7 1 WR06X1802FT 18k 0603 WALSIN EVB_RT8071CGQW-00 October 2015 5 TAIYO http://www.richtek.com RT8071CGQW Evaluation Board your power partner. PCB Layout Top View Bottom View EVB_RT8071CGQW-00 October 2015 6 http://www.richtek.com RT8071CGQW Evaluation Board your power partner. More Information For more information, please find the related datasheet or application notes from Richtek website http://www.richtek.com. Important Notice for Richtek Evaluation Board THIS DOCUMENT IS FOR REFERENCE ONLY, NOTHING CONTAINED IN THIS DOCUMENT SHALL BE CONSTRUED AS RICHTEK’S WARRANTY, EXPRESS OR IMPLIED, UNDER CONTRACT, TORT OR STATUTORY, WITH RESPECT TO THE PRESENTATION HEREIN. IN NO EVENT SHALL RICHTEK BE LIABLE T O BUYER OR USER FOR ANY AND ALL DAMAGES INCLUDING WITHOUT LIMITATION TO DIRECT, INDIRECT, SPECIAL, PUNITIVE OR CONSEQUENTIAL DAMAGES. EVB_RT8071CGQW-00 October 2015 7 http://www.richtek.com