XRP6670EVB

XRP6670 3A 300kHz-2.5MHz Synchronous Step Down Regulator May 2013 Rev. 1.0.1 GENERAL DESCRIPTION EVALUATION BOARD MANUAL The Exar XRP6670 Evaluation board (EVB) is a fully assembled and tested surface-mount PCB that demonstrates the XRP6670 buck regulator. The XRP6670 is a synchronous current mode PWM step-down converter with integrated FET capable of delivering up to 3Amps and optimized for portable batteryoperated applications. A 2.6V to 5.5V input voltage range allows for single supply operation from industry standard 3.3V and 5V power rails. Operating frequency is programmable between 300kHz and 2.5MHz via external resistor ROSC. The integrated Pchannel control FET allows 100% duty cycle. FEATURES • Guaranteed 3A Output Current Built-in over-temperature, overcurrent, shortcircuit and under-voltage lock-out protection insure safe operation under abnormal operating conditions. − Input Voltage: 2.6V to 5.5V • PWM Current Mode Control − Programmable 300kHz to 2.5MHz − 100% Duty Cycle LDO Mode Operation STANDARD CONFIGURATION − Achieves 95% Efficiency • Adjustable Output Voltage Range The XRP6670EVB evaluation board is configured to operate under the following conditions and parameters: • • • • Input voltage range: Output voltage range: Output current/load range: Switching frequency: − 0.8V to 5V with +/-2% Accuracy • Enable and Power Good Functions 2.6V – 5.5V 2.5V 0 – 3A 1MHz • 460µA Quiescent Current • Over-temperature, Overcurrent, Shortcircuit and UVLO Protection EVALUATION BOARD SCHEMATICS VIN L1 R4 10 Ohm U1 XRP6670 6 22uF 7 SHDN 8 R5 0 Ohm 1 R7 DNP R6 0 Ohm 5 Rosc 330k PVDD SW VDD SW PGOOD SHDN/RT PGND EXP PAD C4 1uF PGOOD C1 FB COMP GND CFF 22pF 3 R1 100k C2 22uF 4 9 RC 10k CC 1nF R2 47.5k 10 2 C3 22uF CC1 optional 0 R3 100k VOUT 1.5uH GND GND Fig. 1: XRP6670 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 XRP6670 3A 300kHz-2.5MHz Synchronous Step Down Regulator PIN ASSIGNMENT Fig. 2: XRP6670 Pin Assignment PIN DESCRIPTION Name Pin Number Description SHDN/RT 1 Shutdown and Oscillator resistor input. Connect a resistor to GND from this pin to set the switching frequency. Forcing this pin to VDD shuts down the device. GND 2 Signal ground. All small-signal ground, such as the compensation components and exposed pad should be connected to this, which in turn connects to PGND at one point. SW 3, 4 PGND 5 Power Ground Signal. Connect this signal as close as possible to the input and output capacitors CIN and COUT. PVDD 6 Power Input Supply Pin. Decouple this pin to PGND (pin 5) with a capacitor. VDD 7 Signal Input Supply Pin. Decouple this pin to GND (pin 2) with a capacitor. Typically, VDD and PVDD are connected together. PGOOD 8 Power Good Flag. This is an open drain output and is pulled to ground if the output voltage is out of regulation. FB 9 Feedback pin. An external resistor divider connected to FB programs the output voltage. COMP 10 Exp. Pad Exp. Pad Power switch output pin. This pin is connected to the inductor. Compensation pin. This is the output of transconductance error amplifier and the input to the current comparator. It is used to compensate the control loop. Connect an RC network form this pin to GND. Connect to GND signal (pin 2). ORDERING INFORMATION Refer to XRP6670’s datasheet and/or www.exar.com for exact and up to date ordering information. © 2013 Exar Corporation 2/6 Rev. 1.0.1 XRP6670 3A 300kHz-2.5MHz Synchronous Step Down Regulator external SHDN signal, remove R5/R6 and populate R7 with a 0Ω resistor. Please note that the SHDN signal has to be tri-stated. Depending on the impedance of the tri-state signal there may be some shift in switching frequency. USING THE EVALUATION BOARD POWERING UP THE BOARD Connect a power supply to the VIN and GND pins of the PCB. Upon powering up the XRP6670 will regulate the VOUT at 2.5V nominal. XRP6670 is guaranteed to supply output current of up to 3A and provide nominal efficiency equal to figure 6 of the datasheet. CORRECTION TO DESIGNATOR RC/CC1 Please note that designators for components RC and CC1 have been switched around. In other words the component RC has the designator CC1 and optional component CC1 has designator RC. SHUTDOWN FUNCTION XRP6670 will shut down if SHDN pin is jumpered to the VIN pin. In order to use an © 2013 Exar Corporation 3/6 Rev. 1.0.1 XRP6670 3A 300kHz-2.5MHz Synchronous Step Down Regulator EVALUATION BOARD SCHEMATICS VIN L1 R4 10 Ohm U1 XRP6670 C1 6 22uF 7 SHDN 8 R5 0 Ohm 1 R7 DNP 5 Rosc 330k PVDD SW VDD SW PGOOD SHDN/RT PGND EXP PAD C4 1uF PGOOD FB COMP GND CFF 22pF 3 R1 100k C2 22uF 4 9 RC 10k CC 1nF R2 47.5k 10 2 C3 22uF CC1 optional 0 R3 100k R6 0 Ohm VOUT 1.5uH GND GND BILL OF MATERIAL Reference Designator PCB U1 L1 Qty. Manufacturer Manufacturer Size Component 1 Exar Part Number XRP6670EVB 1.5"x2" XRP6670 Evaluation kit 1 Exar XRP6670 DFN-10 Buck regulator 1 Wurth 74437346015 6.6x7.3mm 1.5uH, 7.2A power inductor Ceramic cap., 22uF, 16V, X5R, 10% C1, C2, C3 3 Murata GRM31CR61C226KE15K 1206 C4 1 Murata GRM188R61C105KA93D 0603 Ceramic cap., 1uF, 16V, X5R, 10% CC 1 Murata GRM188R71H102KA01D 0603 Ceramic cap., 1000pF, 50V, X7R, 10% Ceramic cap., 22pF, 50V, NP0, 10% CFF 1 Murata GRM1885C1H220JA01D 0603 R1, R3 2 Vishay/Dale CRCW0603100KFKEA 0603 RES 100kΩ, 1/10W, 1%, SMD R2 1 Vishay/Dale CRCW060347K5FKEA 0603 RES 47.5kΩ, 1/10W, 1%, SMD RES 10.0Ω, 1/10W, 1%, SMD R4 1 Vishay/Dale CRCW060310R0FKEA 0603 R5, R6 2 Vishay/Dale CRCW06030000Z0EA 0603 RES 0.0Ω, 1/10W, SMD RC 1 Vishay/Dale CRCW060310K0FKEA 0603 RES 10kΩ, 1/10W, 1%, SMD Rosc 1 Vishay/Dale CRCW0603330KFKEA 0603 RES 330kΩ, 1/10W, 1% ,SMD VIN, VOUT, GND, GND, PGOOD, SHDN 6 Vector Electronics K24C/M .042 Dia Test Point Post © 2013 Exar Corporation 4/6 Rev. 1.0.1 XRP6670 3A 300kHz-2.5MHz Synchronous Step Down Regulator EVALUATION BOARD LAYOUT Fig. 3: Component Placement – Top Side Fig. 4: Layout – Top Side Fig. 5: Layout - Bottom © 2013 Exar Corporation 5/6 Rev. 1.0.1 XRP6670 3A 300kHz-2.5MHz Synchronous Step Down Regulator DOCUMENT REVISION HISTORY Revision Date 1.0.0 03/19/13 Initial release of document Description 1.0.1 05/24/13 Changed output voltage from 3.3V to 2.5V BOARD REVISION HISTORY Board Revision Date 146-6698-01 03/19/13 Description Initial release of evaluation board FOR FURTHER ASSISTANCE Email: customersupport@exar.com powertechsupport@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 herein 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. © 2013 Exar Corporation 6/6 Rev. 1.0.1