EVB_RT8086BGQUF

RT8086BGQUF Evaluation Board your power partner. 3.5A, 1.2MHz, Synchronous Step-Down Converter Purpose The RT8086B is a current mode COT step-down converter with the input voltage range from 2.8V to 5.5V and provides 3.5A outputcurrent. This document explains the function and use of the RT8086B 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.................................................................................................................................................... 8 Important Notice for Richtek Evaluation Board ....................................................................................................... 8 EVB_RT8086BGQUF-00 April 2016 1 http://www.richtek.com RT8086BGQUF Evaluation Board your power partner. Introduction General Product Information The RT8086B is a high efficiency, synchronous step-down DC/DC converter. The available input voltage range is from 2.8V to 5.5V and the regulated output voltage is adjustable from 0.6V to 3.3V while delivering up to 3.5A of output current.Product Feature. The internal synchronous low on-resistance power switches increase efficiency and eliminate the need for an external Schottky diode. The current mode constant on-time operation with internal compensation allows the transient response to be optimized over a wide range of loads and output capacitors. The RT8086B is available in the UQFN-12L 2x2 (FC) package. Product Features  High Efficiency Up to 95%  Low RDS(ON) Switches : 50mΩ/40mΩ 0.6V Reference Allows for Low Output Voltage Internal Compensation Input Voltage Range : 2.8V to 5.5V              Adjustable Output Voltage from 0.6V to 3.3V 1.2MHz Switching Frequency Start-Up into Pre-Biased Load Built in Soft-Start Power Good Indication Cycle-by-Cycle Current Limit Input Under Voltage Lockout Output Under Voltage Protection (Hiccup) Thermal Shutdown Protection RoHS Compliant and Halogen Free Key Performance Summary Table Key Features Evaluation Board Number : PCB064_V1 Default Input Voltage 3.3V Max Output Current 3.5A Default Output Voltage 1.2V Default Marking & Package Type RT8086BGQUF, UQFN-12L 2x2 (FC) Operation Frequency 1.2MHz Switching Frequency EVB_RT8086BGQUF-00 April 2016 2 http://www.richtek.com RT8086BGQUF 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 evb_service@richtek.com. 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) PVIN Input voltage Power Input. The available input voltage range is from 2.8V to 5.5V. A 10µF or larger input capacitor is needed to reduce voltage spikes at the input. PGND Ground Power Ground. AGND Ground Analog Ground. NC No Internal Connection No Internal Connection. VOUT Output Voltage Sense Input Pin for Output Voltage. FB Feedback Input Voltage Feedback Input. This pin used to set the output voltage of the converter to regulate to the desired value via an external resistive divider. The feedback reference voltage is 0.6V typically. LX Switch Node test pin Switch Node. Output of the internal high side and low side MOSFETs. EN Enable test point Enable Control Input. A logic-high (1.2V < EN < 5.5V) enables the converter; a logic-low forces the IC into shutdown mode. PGOOD PGOOD test point Power Good Indicator. The output of this pin is an open drain with internal pull-up resister to VIN. The output of this pin is pulled to high when the FB voltage is within 10%; otherwise it is Low. VIN Input Voltage Supply Voltage for Internal Control Circuit. It is connected to PVIN inside the chip. EVB_RT8086BGQUF-00 April 2016 3 http://www.richtek.com RT8086BGQUF Evaluation Board your power partner. Power-up & Measurement Procedure 1. Apply a 3.3V nominal input power supply (2.8V to 5.5V) to the VIN and GND terminals 2. Connect an external load up to 3.5A to the VOUT and GND terminals and verify the output voltage and current. Output Voltage Setting Set the output voltage with the resistive divider (R1, R2) between External Input and GND with the midpoint connected to VREFIN. The output is set by the following formula : VREFIN = External Input R2 / (R1 + R2) EVB_RT8086BGQUF-00 April 2016 4 http://www.richtek.com RT8086BGQUF Evaluation Board your power partner. Schematic, Bill of Materials & Board Layout EVB Schematic Diagram Bill of Materials Reference Qty Part Number Description Package Manufacture C1 1 0603X106M6R3 10µF/X5R/6.3V/0603 C-0603 WALSIN C2, C3 2 C1608X7R1H104KT000N 0.1µF/X7R/50V/0603 C-0603 TDK C4, C5 2 0603X106M6R3 10µF/X5R/6.3V/0603 C-0603 WALSIN C6 1 C1608X7R1H104KT000N 0.1µF/X7R/50V/0603 C-0603 TDK C30 1 NC GP1, GP2 2 GND J1 1 VIN J2 1 VOUT L1 1 PIFE25201B-1R0M 1.0µH R1, R2 2 0603 200K 1% 200k R-0603 WALSIN R3, R4 2 0603 100K 1% 100K R-0603 WALSIN TP1 1 SW TP4 1 PG TP5 1 EN TP6 1 VOUT U1 1 UQFN-12L 2x2 (FC) RICHTEK Z1, Z2, Z3, Z4 4 SIP-1P-M Z5, Z6 2 FK_1 EVB_RT8086BGQUF-00 April 2016 RT8086BGQUF DC/DC Converter 5 Cyntec http://www.richtek.com RT8086BGQUF Evaluation Board your power partner. PCB Layout Top View (1st layer) PCB Layout—Inner Side (2nd Layer) EVB_RT8086BGQUF-00 April 2016 6 http://www.richtek.com RT8086BGQUF Evaluation Board your power partner. PCB Layout—Inner Side (3rd Layer) Bottom View (4th Layer) EVB_RT8086BGQUF-00 April 2016 7 http://www.richtek.com RT8086BGQUF 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_RT8086BGQUF-00 April 2016 8 http://www.richtek.com