RT6200GE Evaluation Board

Purpose

The RT6200 is a high voltage Buck converter that can deliver up to 0.6A output current from a wide input voltage range of 4.5V to 36V. This document explains the function and use of the RT6200 evaluation board (EVB) and provides information to enable operation and modification of the evaluation board and circuit to suit individual requirements.

Introduction

General Product Information

The RT6200 is a high voltage Buck converter that can support the input voltage range from 4.5V to 36V and the output current can be up to 0.6A. Current mode operation provides fast transient response and eases loop stabilization. The chip also provides protection functions such as cycle-by-cycle current limit and thermal shutdown protection. The RT6200 is available in the SOT-23-6 package.

Product Feature

• Wide Operating Input Voltage Range : 4.5V to 36V
• Adjustable Output Voltage Range : 0.8V to 15V
• 0.6A Output Current
• 0.35Ω Internal Power MOSFET Switch
• High Efficiency up to 95%
• 1.2MHz Fixed Switching Frequency (Duty <90%)
• Support duty up to 95%
• Stable with Low ESR Output Ceramic Capacitors
• Thermal Shutdown
• Cycle-By-Cycle Over-Current Protection

Key Performance Summary Table

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.

Power-up & Measurement Procedure

1.Apply a 12V nominal input power supply (4.5V < V_IN < 36V) to the VIN and GND terminals.

2.The EN voltage is pulled to logic high by internal circuit to enable operation. Drive EN high (>2.5V) to enable operation or low (<0.4V) to disable operation.

3.There is a 3-pin header JP2 “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 5.0V) between VOUT and GND.

5.Connect an external load up to 0.6A 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 VOUT and GND with the midpoint connected to FB. The output is set by the following formula:

The installed V_OUT capacitor (C4) is 22μF, 16V X5R ceramic types. Do not exceed their operating voltage range and consider their voltage coefficient (capacitance vs. bias voltage) and ensure that the capacitance is sufficient to maintain stability and provide sufficient transient response for your application. This can be verified by checking the output transient response as described in the RT6200 IC datasheet.

Schematic, Bill of Materials & Board Layout

EVB Schematic Diagram

C2: 10μF/50V/X5R, 1206, TDK C3216X5R1H106K

C4: 22μF/16V/X5R, 1210, Murata GRM32ER61C226K

L1: 15μH TAIYO YUDEN NR8040T150M, DCR=50mΩ

Bill of Materials

EVB Layout

Top View (1^stlayer)

Bottom View (4^th Layer)

Component Placement Guide—Component Side (1^stlayer)

PCB Layout—Component Side (1^stLayer)

PCB Layout—Bottom Side (4^th layer)