RT8092URWSC Evaluation Board your power partner. 3MHz 4A High Efficiency Step-Down Converter with I2C Interface Purpose The RT8092 is a Peak-Current Mode Pulse-Width-Modulated (PWM) step-down DC/DC converter with I2C control interface. The input voltage range from 2.5V to 5.5V and provides 4A output current. This document explains the function and use of the RT8092 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 .......................................................................................................................... 3 Bench Test Setup Conditions ................................................................................................................................. 3 Schematic, Bill of Materials & Board Layout ........................................................................................................... 5 More Information.................................................................................................................................................... 8 Important Notice for Richtek Evaluation Board ....................................................................................................... 8 EVB_RT8092URWSC-00 April 2016 1 http://www.richtek.com RT8092URWSC Evaluation Board your power partner. Introduction General Product Information The RT8092 is a Peak-Current Mode Pulse-Width-Modulated (PWM) step-down DC/DC converter with I2C control interface. Capable of delivering 4A continuing output current over a wide input voltage range from 2.5V to 5.5V, the RT8092 is ideally suited for portable electronic devices that are powered from 1-cell Li-ion battery or from other power sources within the range such as cellular phones, PDAs and handy-terminals. Internal synchronous rectifier with low RDS(ON) dramatically reduces conduction loss at PWM mode. No external Schottky barrier diode is required in practical application. The RT8092 enters low-dropout mode when normal PWM cannot provide regulated output voltage by continuously turning on the upper P-MOSFET. The RT8092 enters shutdown mode and consumes less than 5μA when the EN pin is pulled low. The switching ripple is easily smoothedout by small package filtering elements due to a fixed operation frequency of 3MHz. Along with its small WL-CSP-15B 1.2x2 (BSC) package, it is suitable for applications requiring small PCB area. To increase battery life time, the RT8092 provides low power mode with IQ < 15µA in standby and light-load applications. The RT8092 also includes Dynamic Voltage Scaling (DVS) for system low power applications. The I2C interface let the RT8092 controllable flexibly to select VOUT voltage level, peak current limit level, PWM control mode, and so on. Other features include soft-start, auto discharge, lower internal reference voltage, overtemperature, and over-current protection. Product Feature 2.5V to 5.5V Input Range Low Operation Quiescent Current Normal Mode IQ < 60µA Low Power Mode IQ < 15μA Output range From 0.3V to 5.5V Bank 0 : 0.3V to 0.7V Bank 1 : 0.6V to 1.4V Bank 2 : 1.2V to 2.8V Bank 3 : 2.4V to 5.5V The Default Value is 2.8V (VSEL = High) and 1V (VSEL = Low) 4A Continuing Output Current Support DVS in the Same Bank VOUT Adjusting Range (max, min) is Settable High Efficiency 90% at 5V2.8V with 1.5A Load 3MHz Fixed-Frequency PWM Operation Auto-PSM/PWM or Force-PWM Selectable Support Remote Ground Sensing for Accurate Output Voltage EVB_RT8092URWSC-00 April 2016 2 http://www.richtek.com RT8092URWSC Evaluation Board your power partner. Key Performance Summary Table Key Features Evaluation Board Number : PCB016_V1 Default Input Voltage 3.3V Max Output Current 4A Default Output Voltage 1.0V with VSEL = L Default Marking & Package Type RT8092URWSC, WL-CSP-15B 1.2x2 (BSC) Operation Frequency Steady 3MHz at all loads Bench Test Setup Conditions 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) BAT Input voltage Power input. Support 2.5V to 5.5V Input Voltage. Must bypass with a suitable large ceramic capacitor at this pin. EN Enable test point High = Enable. GND Ground Ground. VSEL Nominal VOUT setting select input pin VSEL = Low selects {0x11.ENSEL0, 0x11.VoutSEL0[6:0], 0x14.PWM0}. VSEL = High selects {0x10.ENSEL1, 0x10.VoutSEL1[6:0], 0x14.PWM1}. VOUT Output voltage Power output. Must bypass with a suitable large ceramic capacitor at this pin. EVB_RT8092URWSC-00 April 2016 3 http://www.richtek.com RT8092URWSC Evaluation Board your power partner. Test point/ Pin name Signal Comment (expected waveforms or voltage levels on test points) VOUTR Output Voltage Sense Input Output feedback pin. GNDR Remote Ground Sense Input Connect to GND as short as possible. LX Switch node test point Connect this pin to an external L-C filter. Power-up & Measurement Procedure 1. Connect input power (2.5V < 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 2-pin switch “EN” for enable control. To switch up position to tie EN test pin to input power VBAT for enabling the device. Inversely, to switch down position to tie EN test pin and ground GND for disabling the device. 4. Verify the output voltage (1.0V with VSEL = L or 2.8V with VSEL = H) between VOUT and GND. 5. Connect an external load up to 4A to the VOUT and GND terminals and verify the output voltage and current. Output Voltage Setting Set the output voltage by VSEL pin between BAT and GND. There is a 3-pin header “VSEL” for VOUT selection. To use a jumper at “H” option to tie VSEL test pin to input power BAT for VOUT = 2.8V (dafult setting). Inversely, to use a jumper at “L” option to tie VSEL test pin to ground GND for VOUT = 1.0V (default setting). EVB_RT8092URWSC-00 April 2016 4 http://www.richtek.com RT8092URWSC Evaluation Board your power partner. Schematic, Bill of Materials & Board Layout EVB Schematic Diagram Bill of Materials Reference Qty Part Number Description Package Manufacture U1 1 RT8092URWSC Buck Converter WL-CSP-15B 1.2x2 (BSC) RICHTEK C1 1 0603X106M6R3 10µF/6.3V/X5R C-0603 WALSIN C4 1 C2012X5R0J226K 22µF/6.3V/X5R C-0805 TDK C8 1 C1608X5R0J1A104K 1µF/6.3V/X5R C-0603 TDK R5 1 RM06FTN1005 100k/1%/0603 R-0603 WALSIN R14 1 RM06FTN2202 220/1%/0603 R-0603 TA-I R9, R10 2 RM06FTN1003 1k/1%/0603 R-0603 WALSIN L1 1 XFL4015-331MEC 0.33µH/R33C L-4015 Coilcraft EVB_RT8092URWSC-00 April 2016 5 http://www.richtek.com RT8092URWSC Evaluation Board your power partner. PCB Layout Top View (1st layer) PCB Layout—Inner Side (2nd Layer) EVB_RT8092URWSC-00 April 2016 6 http://www.richtek.com RT8092URWSC Evaluation Board your power partner. PCB Layout—Inner Side (3rd Layer) Bottom View (4th Layer) EVB_RT8092URWSC-00 April 2016 7 http://www.richtek.com RT8092URWSC 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 TO BUYER OR USER FOR ANY AND ALL DAMAGES INCLUDING WITHOUT LIMITATION TO DIRECT, INDIRECT, SPECIAL, PUNITIVE OR CONSEQUENTIAL DAMAGES. EVB_RT8092URWSC-00 April 2016 8 http://www.richtek.com