XRP6658EVB

XRP6658EVB 1A 1.5MHz Synchronous Step-Down Converter February 2012 Rev. 2.1.0 GENERAL DESCRIPTION EVALUATION BOARD MANUAL The XRP6658 is a synchronous current mode PWM step down (buck) converter capable of delivering up to 1Amp of current and optimized for portable battery-operated applications. Based on a current-mode 1.5MHz constant frequency PWM control scheme, the XRP6658 reduces the overall component count and solution footprint. It provides low output voltage ripple and excellent line and load regulation. It also implements a PFM mode to improve light load efficiency as well as a 100% duty cycle LDO mode. Output voltage is adjustable to as low as 0.6V with a better than 3% accuracy while a low quiescent current supports the most stringent battery operating conditions. FEATURES  Guaranteed 1A Output Current  Input Voltage: 2.5V to 5.5V  1.5MHz PWM Current Mode Control Built-in over temperature and under voltage lock-out protections insure safe operations under abnormal operating conditions.  PFM Mode Operations at Light Load The XRP6658 is offered in a RoHS compliant, “green”/halogen free 5-pin SOT23 package.  Adjustable Output Voltage Range  100% Duty Cycle LDO Mode Operations  Achieves 97% Efficiency  As Low as 0.6V with ±3% Accuracy  Internal Compensation Network  Over Temperature & UVLO Protection EVALUATION BOARD SCHEMATICS Fig. 1: XRP6658EVB Evaluation Board Schematics Exar Corporation 48720 Kato Road, Fremont CA 94538, USA www.exar.com Tel. +1 510 668-7000 – Fax. +1 510 668-7001 XRP6658EVB 1A 1.5MHz Synchronous Step-Down Converter PIN ASSIGNMENT Fig. 2: XRP6658 Pin Assignment PIN DESCRIPTION Name Pin Number Description VIN 1 Power Input Pin. Must be closely decoupled to GND pin with a 4.7μF or greater ceramic capacitor. GND 2 Ground Signal EN 3 Enable Pin. Minimum 1.2V to enable the device. Maximum 0.4V to shutdown the device. VFB 4 Feedback Pin. Receives the feedback voltage from an external resistive divider across the output. SW 5 Switch Pin. Must be connected to Inductor. This pin connects to the drains of the internal main and synchronous power MOSFET switches. ORDERING INFORMATION Refer to XRP6658’s datasheet and/or www.exar.com for exact and up to date ordering information. © 2012 Exar Corporation 2/7 Rev. 2.1.0 XRP6658EVB 1A 1.5MHz Synchronous Step-Down Converter USING THE EVALUATION BOARD set by the feedback resistors. The board will operate with a load current IOUT of up to 1A and provide efficiency equal to figures 4 and 5 of XRP6658 datasheet. INITIAL SETUP Set the input supply to a voltage between 2.5V to 5.5V and connect it to VIN and GND connectors on the left side of the evaluation board. Connect the load to the VOUT and GND connectors on the right hand side of the board. Check to make sure that jumper J1 is set to VIN. The board will power-up and regulate to the desired output voltage VOUT © 2012 Exar Corporation JUMPER J1 FUNCTION Jumper J1 can be used to either short EN pin to VIN or to GND. The Board is supplied from EXAR with the jumper set to connect EN to VIN. 3/7 Rev. 2.1.0 GND EN VIN 1 1 1 CIN2 NP 1 CIN1 4.7uF 4/7 J1 2 VIN = 3.3V to 5.5V 3 3 1 EN VIN VFB SW U1 XRP6658 GND © 2012 Exar Corporation 2 4 5 C1 22pF SW 2.2uH L1 1 100k R2 453k R1 COUT1 10uF COUT2 NP 1 1 1 GND VFB VOUT VOUT = 3.3V XRP6658EVB 1A 1.5MHz Synchronous Step-Down Converter EVALUATION BOARD SCHEMATICS Rev. 2.1.0 XRP6658EVB 1A 1.5MHz Synchronous Step-Down Converter BILL OF MATERIAL Ref. Qty Manufacturer Part Number Size Component EVAL BD 1 Exar Corp 146-6685-02 U1 1 Exar Corp XRP6658 SOT 23-5 Synchronous Step-Down Regulator CIN1 1 Murata GRM21BR71C475KA73L 0805 Ceramic 4.7µF, 16V, X7R CIN2 1 COUT1 1 COUT2 1 C1 1 Murata GRM1885C1H220JA01D 0603 Ceramic 22pF, 50V, C0G L1 1 Wurth Electronik 7440430022 4.8mm x 4.8mm x 2.8mm Inductor 2.2uH, 2.5A, 23mΩ R1 1 Vishay CRCW0603453KFKTA 0603 453KΩ Resistor, 0.1W, 1% R2 1 Vishay CRCW0603100KFKTA 0603 100KΩ Resistor, 0.1W, 1% J1 1 Wurth Electronik 61303611121 0.64mm SQ x 6mm 3 Pin Header, 2.54mm pitch J1 (Jumper) 1 Wurth Electronik 609002115121 0.1” Jumper short Test Point VIN, VOUT, EN, SW, GND, VFB 7 Mill-Max 0300-115-01-4727100 0.042” diameter Test Point Post XRP6658 Evaluation Board Not populated Murata GRM21BR71A106KE51L 0805 Ceramic 10uF, 10V, X7R Not populated © 2012 Exar Corporation 5/7 Rev. 2.1.0 XRP6658EVB 1A 1.5MHz Synchronous Step-Down Converter EVALUATION BOARD LAYOUT Fig. 3: Component Placement – Top Side Fig. 4: Component Placement 2 – Top Side Fig. 5: Layout – Top Side Fig. 6: Layout – Bottom Side © 2012 Exar Corporation 6/7 Rev. 2.1.0 XRP6658EVB 1A 1.5MHz Synchronous Step-Down Converter REVISION HISTORY Revision Date 1.0.0 09/16/2010 Initial release of document Description 2.0.0 10/06/2010 Updated evaluation board schematics and lay out. 2.1.0 02/07/2012 Updated bill of material and schematics FOR FURTHER ASSISTANCE Email: customersupport@exar.com Exar Technical Documentation: http://www.exar.com/TechDoc/default.aspx? EXAR CORPORATION HEADQUARTERS AND SALES OFFICES 48720 Kato Road Fremont, CA 94538 – USA Tel.: +1 (510) 668-7000 Fax: +1 (510) 668-7030 www.exar.com NOTICE EXAR Corporation reserves the right to make changes to the products contained in this publication in order to improve design, performance or reliability. EXAR Corporation assumes no responsibility for the use of any circuits described herein, conveys no license under any patent or other right, and makes no representation that the circuits are free of patent infringement. Charts and schedules contained here in are only for illustration purposes and may vary depending upon a user’s specific application. While the information in this publication has been carefully checked; no responsibility, however, is assumed for inaccuracies. EXAR Corporation does not recommend the use of any of its products in life support applications where the failure malfunction of the product can reasonably be expected to cause failure of the life support system or to significantly affect safety or effectiveness. Products are not authorized for use in such applications unless EXAR Corporation receives, writing, assurances to its satisfaction that: (a) the risk of injury or damage has been minimized; (b) the user assumes such risks; (c) potential liability of EXAR Corporation is adequately protected under the circumstances. or its in all Reproduction, in part or whole, without the prior written consent of EXAR Corporation is prohibited. © 2012 Exar Corporation 7/7 Rev. 2.1.0