XRP7664-65-74-75 2A/3A 18V Synchronous Step-Down Regulator, Constant frequency (XRP7664-65), Light-Load efficiency (XRP7674-75) August 2014 Rev. 2.0.0 GENERAL DESCRIPTION EVALUATION BOARD MANUAL The EXAR XRP76XX Evaluation kit is a fully assembled and tested surface-mount PCB that demonstrates the XRP7664, XRP7665, XRP7674 and XRP7675 synchronous buck regulators. The current-mode switching regulator generates a preset 3.3V output with a load of up to 2A (XRP7664, XRP7674) and 3A (XRP7665, XRP7675). The EVB kit requires a single input voltage VIN source if EN is tied to VIN via jumper J1 (default setting as supplied from EXAR). If J1 is set to EN=EXT position then a logic-level FEATURES signal is required at EN pin in order to turn the regulator on and off. • 2A/3A Continuous Output Current • 4.5V to 18V Wide Input Voltage STANDARD CONFIGURATION • PWM Current-Mode Control The XRP76XXEVB evaluation board is • Adjustable Output Voltage configured to operate under the following conditions and parameters: - 2% Accuracy • Input voltage range: 4.5V - 18V • Programmable Soft-Start and Enable • Output voltage range: 3.3V Function • Output current/load range: 0 – 2A/3A • Constant frequency (XRP7664-65) • Light-load efficiency (XRP7674-75) • Built-in Thermal, Over Current, UVLO and Output Over-Voltage Protections • RoHS Compliant “Green”/Halogen Free 8-Pin Exposed Pad SOIC Package EVALUATION BOARD SCHEMATICS J1 R4 100k EN=VIN 123 EN=EXT EN 1 CBS 10nF UXR1P76XX CSS 0.1uF SW 1 8 1 VIN BS SS 2 7 IN EN L1 VOUT 3 6 SW SW COMP C2 C1 SW 4 GND FB 5 CDCN1P CnCF uH R261.1k DNP uF FB FB C3 C4 RC 22uF 22uF k R2 GND 10k GND Fig. 1: XRP76XX Evaluation Board Schematics Exar Corporation www.exar.com 48720 Kato Road, Fremont CA 94538, USA Tel. +1 510 668-7000 – Fax. +1 510 668-7001

XRP7664-65-74-75 2A/3A 18V Synchronous Step-Down Regulator, Constant frequency (XRP7664-65), Light-Load efficiency (XRP7674-75) PIN ASSIGNMENT Fig. 2: XRP7664-65-74-75 Pin Assignment, Exposed Pad applicable to XRP7665 and XRP7675 PIN DESCRIPTION Name Pin Number Description Bootstrap pin. Connect a 0.01uF or larger bootstrap capacitor between the BS pin and BS 1 the SW pin. The voltage across the bootstrap capacitor drives the internal high-side power MOSFET. Supply input pin. A capacitor should be connected between the IN pin and GND pin to IN 2 keep the input voltage constant. Power switch output pin. This pin is connected to the inductor and the bootstrap SW 3 capacitor. GND 4 Ground pin. Feedback pin. An external resistor divider connected to FB programs the output voltage. If the feedback pin exceeds 1.1V the over-voltage protection will trigger. If the FB 5 feedback voltage drops below 0.3V the oscillator frequency is lowered to short-circuit protection. Compensation pin. This is the output of transconductance error amplifier and the input COMP 6 to the current comparator. It is used to compensate the control loop. Connect an RC network form this pin to GND. Control input pin. EN 7 Drive EN high/low in order to turn on/off the regulator. When the IC is in shutdown mode all functions are disabled to decrease the supply current below 0.1µA nominal. Soft-start control input pin. Connect a capacitor from SS to GND to set the soft-start SS 8 period. A 0.1µF capacitor sets the soft start period to 15ms. To disable the soft-start feature, leave SS unconnected. ORDERING INFORMATION Refer to XRP7664-65-74-75’s datasheet and/or www.exar.com for exact and up to date ordering information. © 2014 Exar Corporation 2/8 Rev. 2.0.0

XRP7664-65-74-75 2A/3A 18V Synchronous Step-Down Regulator, Constant frequency (XRP7664-65), Light-Load efficiency (XRP7674-75) USING THE EVALUATION BOARD supplied from EXAR with jumper set at left- side (position marked EN=VIN). This allows for INITIAL SETUP automatic startup of the XRP76XX regulator when VIN is applied. Set the input supply to 12V and connect it to VIN and GND connectors on the left side of the SETTING THE OUTPUT VOLTAGE evaluation board. Connect the load to the VOUT and GND connectors at the right side of Use an external resistor divider to set the the board. Check to make sure that jumper J1 output voltage. Program the output voltage is set to the left side (position marked from: EN=VIN). The board will power up and regulate the output at 3.3V upon turning on (cid:7)(cid:8)(cid:9)(cid:10) (cid:1)1(cid:3)(cid:1)2(cid:5)(cid:6) (cid:15)1(cid:16) the input supply. The XRP76XX should provide 0.925(cid:7) nominal efficiency equal to figure 4 of the Where: datasheet. R1 is the resistor between V and FB OUT JUMPER J1 FUNCTION R2 is the resistor between FB and GND (nominally 10kΩ) Jumper J1 can be used to either connect EN to 0.925V is the nominal feedback voltage. VIN or allow an independent logic-level control signal to be applied to EN. The board is © 2014 Exar Corporation 3/8 Rev. 2.0.0

XRP7664-65-74-75 2A/3A 18V Synchronous Step-Down Regulator, Constant frequency (XRP7664-65), Light-Load efficiency (XRP7674-75) EVALUATION BOARD SCHEMATICS J1 EN=VIN 123 EN=EXT EN R4 100k 1 U1 SW CBS 10nF XRP76XX CSS 0.1uF 1 8 1 BS SS VIN 2 7 IN EN L1 VOUT 3 6 SW SW COMP CC1 CC uH SW 4 5 R1 C2 C1 GND FB DNP nF 26.1k DNP uF C3 C4 FB FB RC 22uF 22uF k R2 GND 10k GND © 2014 Exar Corporation 4/8 Rev. 2.0.0

XRP7664-65-74-75 2A/3A 18V Synchronous Step-Down Regulator, Constant frequency (XRP7664-65), Light-Load efficiency (XRP7674-75) XRP7664 BILL OF MATERIAL Reference Qty. Manufacturer Part Number Size Component PCB 1 Exar XRP7664EVB 1.3"x2" XRP7664 Evaluation kit U1 1 Exar XRP7664 SO-8 2A Buck regulator L1 1 COOPER-Bussmann DR74-100R 7.6x7.6mm 10uH shielded inductor C1 1 Murata Corp. GRM32DR61E106KA12L 1210 CER CAP 10uF, 25V, X5R C3, C4 2 Murata Corp. GRM31CR61A226ME19L 1206 CER CAP 22uF, 10V, X5R CBS 1 Murata Corp. GRM188R71H103KA01D 0603 CAR CEP 10000pF, X7R, 50V CC 1 Murata Corp. GRM188R71H332KA01D 0603 CAP CER 3300pF, X7R, 50V CSS 1 Murata Corp. GRM188R71H104KA57D 0603 CAP CER 0.1uF, X7R, 50V R1 1 Panasonic ERJ-3EKF2612V 0603 Resistor 26.1K Ohm, 1% R2 1 Panasonic ERJ-3EKF1002V 0603 Resistor 10K Ohm, 1% RC 1 Panasonic ERJ-3EKF5621V 0603 Resistor 5.62K Ohm, 1% R4 1 Panasonic ERJ-3EKF1003V 0603 Resistor 100K Ohm, 1% J1 1 Wurth Elektronik 61304011121 Conn. Header 0.1" 3POS J1(JUMPER) 1 Wurth Elektronik 609002115121 CONN JUMPER SHORT. VIN, VOUT, GND, EN, SW 6 Vector Electronic K24C/M .042 Dia Test Point Post XRP7665 BILL Of MATERIAL Reference Qty. Manufacturer Part Number Size Component PCB 1 Exar XRP7665EVB 1.3"x2" XRP7665 Evaluation kit U1 1 Exar XRP7665 PSO-8 3A Buck Regulator L1 1 Wurth Elektronik 744314850 7x7x5mm 8.5uH shielded inductor C1 1 Murata Corp. GRM32ER61E226KE15L 1210 CER CAP 22uF, 25V, X5R C3, C4 2 Murata Corp. GRM31CR61A226KE19L 1206 CER CAP 22uF, 10V, X5R CBS 1 Murata Corp. GRM188R71H103KA01D 603 CAP CEP 10000pF, X7R, 50V CC 1 Murata Corp. GRM188R71H392KA01D 603 CAP CER 3900pF, X7R, 50V CSS 1 Murata Corp. GRM188R71H104KA57D 603 CAP CER 0.1uF, X7R, 50V R1 1 Panasonic ERJ-3EKF2612V 603 Resistor 26.1k Ohm, 1% R2 1 Panasonic ERJ-3EKF1002V 603 Resistor 10k Ohm, 1% RC 1 Panasonic ERJ-3EKF6821V 603 Resistor 6.81k Ohm, 1% R4 1 Panasonic ERJ-3EKF1003V 603 Resistor 100k Ohm, 1% J1 1 Wurth Elektronik 61304011121 Conn. Header 0.1" 3POS J1(JUMPER) 1 Wurth Elektronik 609002115121 CONN JUMPER SHORT. VIN, VOUT, GND, EN, SW 6 Vector Electronic K24C/M .042 Dia Test Point Post © 2014 Exar Corporation 5/8 Rev. 2.0.0

XRP7664-65-74-75 2A/3A 18V Synchronous Step-Down Regulator, Constant frequency (XRP7664-65), Light-Load efficiency (XRP7674-75) XRP7674 BILL OF MATERIAL Reference Qty. Manufacturer Part Number Size Component PCB 1 Exar XRP7674EVB 1.3"x2" XRP7674 Evaluation kit U1 1 Exar XRP7674 SO-8 2A Buck Regulator, light-load efficient L1 1 COOPER-Bussmann DR74-100R 7.6x7.6mm 10uH shielded inductor C1 1 Murata Corp. GRM32DR61E106KA12L 1210 CER CAP 10uF, 25V, X5R C3, C4 2 Murata Corp. GRM31CR61A226ME19L 1206 CER CAP 22uF, 10V, X5R CBS 1 Murata Corp. GRM188R71H103KA01D 0603 CAR CEP 10000pF, X7R, 50V CC 1 Murata Corp. GRM188R71H472KA01D 0603 CAP CER4700pF, X7R, 50V CSS 1 Murata Corp. GRM188R71H104KA57D 0603 CAP CER 0.1uF, X7R, 50V R1 1 Vishay/Dale CRCW060326K1FKEA 0603 Resistor 26.1K Ohm, 1% R2 1 Vishay/Dale CRCW060310K0FKEA 0603 Resistor 10K Ohm, 1% RC 1 Vishay/Dale CRCW060313K0FKEA 0603 Resistor 13K Ohm, 1% R4 1 Vishay/Dale CRCW0603100KFKEA 0603 Resistor 100K Ohm, 1% J1 1 Wurth Elektronik 61304011121 Conn. Header 0.1" 3POS J1(JUMPER) 1 Wurth Elektronik 609002115121 CONN JUMPER SHORT. VIN, VOUT, GND, EN, SW 6 Vector Electronic K24C/M .042 Dia Test Point Post XRP7675 BILL Of MATERIAL Reference Qty. Manufacturer Part Number Size Component PCB 1 Exar XRP7675EVB 1.3"x2" XRP7675 Evaluation kit U1 1 Exar XRP7675EVB PSO-8 3A Buck Regulator, Light-Load efficient L1 1 Wurth Elektronik 744314850 7x7x5mm 8.5uH shielded inductor C1 1 Murata Corp. GRM32ER61E226KE15L 1210 CER CAP 22uF, 25V, X5R C3, C4 2 Murata Corp. GRM31CR61A226ME19L 1206 CER CAP 22uF, 10V, X5R CBS 1 Murata Corp. GRM188R71H103KA01D 603 CAR CEP 10000pF, X7R, 50V CC 1 Murata Corp. GRM188R71H332KA01D 603 CAP CER 3300pF, X7R, 50V CSS 1 Murata Corp. GRM188R71H104KA57D 603 CAP CER 0.1uF, X7R, 50V R1 1 Vishay/Dale CRCW060326K1FKEA 603 Resistor 26.1K Ohm, 1% R2 1 Vishay/Dale CRCW060310K0FKEA 603 Resistor 10K Ohm, 1% RC 1 Vishay/Dale CRCW060313K0FKEA 603 Resistor 13K Ohm, 1% R4 1 Vishay/Dale CRCW0603100KFKEA 603 Resistor 100K Ohm, 1% J1 1 Wurth Elektronik 61304011121 Conn. Header 0.1" 3POS J1(JUMPER) 1 Wurth Elektronik 609002115121 CONN JUMPER SHORT. VIN, VOUT, GND, EN, SW 6 Vector Electronic K24C/M .042 Dia Test Point Post © 2014 Exar Corporation 6/8 Rev. 2.0.0

XRP7664-65-74-75 2A/3A 18V Synchronous Step-Down Regulator, Constant frequency (XRP7664-65), Light-Load efficiency (XRP7674-75) EVALUATION BOARD LAYOUT Fig. 3: Component Placement – Top Side Fig. 4: Layout – Bottom Side © 2014 Exar Corporation 7/8 Rev. 2.0.0

XRP7664-65-74-75 2A/3A 18V Synchronous Step-Down Regulator, Constant frequency (XRP7664-65), Light-Load efficiency (XRP7674-75) DOCUMENT REVISION HISTORY Revision Date Description 1.0.0 10/29/10 Initial release of XRP7664-65 EVB Manual 1.0.0 03/22/13 Initial release of XRP7674-75 EVB Manual 2.0.0 08/19/14 Initial release of combined XRP7664-65-74-75 EVB Manual BOARD REVISION HISTORY Board Revision Date Description 146-6688-01 10/29/10 Initial release of evaluation board XRP7664-65 146-6688-04 03/22/13 Initial release of evaluation board XRP7674-75 146-6688-05 08/19/14 Initial release of combined XRP7664-65-74-75 EVB FOR FURTHER ASSISTANCE Email: customersupport@exar.com Powertechsupport@exar.com Exar Technical Documentation: http://www.exar.com/TechDoc/ 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 or malfunction of the product can reasonably be expected to cause failure of the life support system or to significantly affect its safety or effectiveness. Products are not authorized for use in such applications unless EXAR Corporation receives, in writing, assurances to its satisfaction that: (a) the risk of injury or damage has been minimized; (b) the user assumes all such risks; (c) potential liability of EXAR Corporation is adequately protected under the circumstances. Reproduction, in part or whole, without the prior written consent of EXAR Corporation is prohibited. © 2014 Exar Corporation 8/8 Rev. 2.0.0