November 2013 Rev VIN FDMS7578. L1 IHLP-5050FD-01 41A, 1mOhm. Csnub 0 Ohm FDMS7650DC. 0 Ohm. 6.8nF. CFF 0.56nF

Transcription

1 XRP64 November 0 Rev..0.0 GENERAL DESCRIPTION The XRP64 is a synchronous step-down controller for point-of load supplies up to 5A. A wide 4.5V to V input voltage range allows for single supply operation from industry standard 5V, V and 9.6V rails. With a proprietary emulated current mode Constant On-Time (COT) control scheme, the XRP64 provides extremely fast line and load transient response using ceramic output capacitors. It requires no loop compensation hence simplifying circuit implementation and reducing overall component count. The control loop also provides exceptional line regulation and maintains constant operating frequency. A selectable power saving mode, allows the user to operate in discontinuous mode (DCM) at light current loads thereby significantly increasing the converter efficiency. A host of protection features, including overcurrent, over-temperature, short-circuit and UVLO, help achieve safe operation under abnormal operating conditions. EVALUATION BOARD MANUAL FEATURES 5A Capable Step Down Controller Wide Input Voltage Range o 5V to V Single Supply o 4.5V to 5.5V Low Vin Integrated high Current A/A Drivers 0.6V to 8V Adjustable Output Voltage Proprietary Constant On-Time Control No Loop Compensation Required Ceramic Output Cap. Stable operation Programmable 00ns-µs Quasi Constant 00kHz-800kHz Freq. Selectable CCM or CCM/DCM Operation D MMSZ4699TG R9.5k, R8 k, R7 6k, R6 k J C,C,C,C4 CERAMIC 0 X7R V + EN/MODE Forced CCM DCM/CCM RLIM.8k,% C C C C4 C5 T9 T0 - RON.8k CBST uf MT FDMS7578 PWRGD CSS 47nF R4 0k SS PGOOD FB EXPAD TON 8 EN 7 ILIM 6 5 BST U XRP PGND GH 4 SW NC GL RBST 0 Ohm T5 T7 T6 T8 MB FDMS7650DC L IHLP-5050FD-0 4A, mohm Rsnub Ohm R Csnub 0 Ohm 6.8nF C5,C6,C7,C8 0-5A R5TPE0M7 C6 C7 C8 C9 C0 C C C T 0uF 0uF 0uF 0uF OPEN OPEN OPEN OPEN T VOUT+ VOUT- CIN 0.uF CFF 0.56nF R 0k,% C 4.7uF R5 OPEN R 0k,% T T4 Fig. : XRP64 Evaluation Board Schematics Exar Corporation Kato Road, Fremont CA 9458, USA Tel Fax

2 XRP64 PIN ASSIGNMENT PGND GL NC FB EXPOSED PAD SW 0 PGOOD GH 4 9 SS BST ILIM EN TON Fig. : XRP64 Pin Assignment PIN DESCRIPTION Name Pin Number Description GL Driver output for Low-side N-channel synchronous MOSFET. NC Internally not connected. Leave this pin floating. SW Lower supply rail for high-side gate driver GH. Connect this pin to the junction between the two external N-channel MOSFETs. GH 4 Driver output for high-side N-channel switching MOSFET. BST 5 High-side driver supply pin. Connect a 0.uF bootstrap capacitor between BST and SW. ILIM 6 EN/MODE 7 Over-current protection programming. Connect with a resistor to the Drain of the lowside MOSFET. Precision enable pin. Pulling this pin above.9v will turn the IC on and it will operate in Forced CCM. If the voltage is raised above.0v then the IC will operate in DCM or CCM depending on load. TON 8 Constant on-time programming pin. Connect with a resistor to. SS 9 PGOOD 0 Soft-Start pin. Connect an external capacitor between SS and to program the soft-start rate based on the 0uA internal source current. Power-good output. This open-drain output is pulled low when V OUT is outside the regulation. FB Feedback input to feedback comparator. Connect with a set of resistors to VOUT and GND in order to program V OUT., Analog ground. Control circuitry of the IC is referenced to this pin. 4 IC supply input. Provides power to internal LDO. 5 The output of LDO. For operation using a 5V rail, should be shorted to. PGND 6 Ground for low side driver Exposed Pad Thermal pad for heat dissipation. Connect to with a short trace. ORDERING INFORMATION Refer to XRP64 s datasheet and/or for exact and up to date ordering information. 0 Exar Corporation /7 Rev..0.0

3 XRP64 USING THE EVALUATION BOARD POWERING UP Connect the +/- with short/thick leads to power supply. Connect VOUT+/VOUT- with short/thick leads to electronic load. Apply V using the power supply. The XRP64EVB should power up and regulate the output at.v. Rated output current is 5A. Overcurrent protection should trigger at about 4A. JUMPER J With the jumper set at CCM position the converter will operate in Forced CCM at =V(+/-0%). In order to operate in Forced CCM over a wider range, remove Jumper and apply an auxilary voltage in the range of.9v-v to the EN test point. With the jumper set at DCM/CCM position the converter will operate at DCM/CCM, depending on load, at =V(+/-0%). In order to operate in DCM/CCM over a wider range, remove Jumper and apply an auxilary voltage in the range of.v-5v to the EN test point. 0 Exar Corporation /7 Rev..0.0

4 XRP64 EVALUATION BOARD SCHEMATICS D MMSZ4699TG R9.5k, R8 k, R7 6k, R6 k J C,C,C,C4 CERAMIC 0 X7R V + EN/MODE Forced CCM DCM/CCM RLIM.8k,% C C C C4 C5 T9 T0 - RON.8k CBST uf MT FDMS7578 PWRGD CSS 47nF R4 0k SS PGOOD FB EXPAD TON 8 EN 7 ILIM 6 5 BST U XRP PGND 6 GH 4 SW NC GL RBST 0 Ohm T5 T7 T6 T8 MB FDMS7650DC Rsnub Ohm Csnub 6.8nF L IHLP-5050FD-0 4A, mohm R 0 Ohm C5,C6,C7,C8 POSCAP 0-5A C6 C7 C8 C9 C0 C C C T 0uF 0uF 0uF 0uF OPEN OPEN OPEN OPEN T VOUT+ VOUT- CIN 0.uF CFF 0.56nF R 0k,% C 4.7uF R5 OPEN R 0k,% T T4 0 Exar Corporation 4/7 Rev..0.0

5 XRP64 BILL OF MATERIAL Reference Qty. Manufacturer Manufacturer Size Component Designator Part Number PCB Exar XRP64EVB XRP64 Evaluation kit U Exar XRP64 QFN-6 Constant On-Time Buck controller MT FAIRCHILD FDMS7578 Power SO-8 N-Ch. 5V, 5.8mOhm MOSFET MB FAIRCHILD FDMS7650DC Power SO-8 N-Ch. 0V, 00A, 0.99mOhm, MOSFET D ON SEMI MMSZ4699TG SOD- Diode Zener V, 500MW, L VISHAY-DALE IHLP5050FDERR47M0.x.9mm Shielded inductor, 0.47uH, mω, 4A C-C4 4 MURATA GRMER7E6KE5L 0 CERAMIC CAP.,, 5V, X7R, 0% C5 0 DONT POPULATE C6-C9 4 PANASONIC R5TPE0M7 7.X4.X.8mm TANTALUM CAP., 0uF,.5V, 97 C0-C 0 DONT POPULATE CBST MURATA GRM88R7C05KAD 060 CERAMIC CAP., uf, 6V, X7R, 0% CFF MURATA GRM88R7H56KA0D 060 CERAMIC CAP, 0.56nF, 50V, X7R, 0% CIN MURATA GRM88R7H04KA9D 060 CERAMIC CAP., 0.uF, 50V, X7R, 0% C MURATA GRMBR7C475KA7L 0805 CERAMIC AP., 4.7uF, 6V, X7R, 0% CSS MURATA GRM88R7H47KA6D 060 CERAMIC CER, 47nF, 50V, X7R, 0% Csnub MURATA GRM88R7H68KA0D 060 CERAMIC CER, 6.8nF, 50V, X7R, 0% R, R, R4 PANASONIC ERJ-EKF00V 060 Resistor 0k, /0W, %, SMD R, RBST PANASONIC ERJ-GEY0R00V 060 Resistor 0Ω, Jumper SMD R5 0 DONT POPULATE R9 PANASONIC ERJ-EKF49V 060 Resistor.49K Ohm, /0w, %, SMD R6 PANASONIC ERJ-EKF00V 060 Resistor K Ohm, /0W, %, SMD R7 PANASONIC ERJ-EKF604V 060 Resistor 6.04K Ohm, /0W, %, SMD R8 PANASONIC ERJ-EKF00V 060 Resistor K Ohm, /0W, %, SMD RLIM PANASONIC ERJ-EKF8V 060 Resistor.8k, /0W, %, SMD RON PANASONIC ERJ-EKF8V 060 Resisrtor.8K Ohm ohm, /0W,%, SMD Rsnub PANASONIC ERJ-6RQFR0V 0805 Resisrtor.0 Ohm, /8W,%, SMD J Wurth Elektronik 600 -PIN CONNECTOR +, -, VOUT+, VOUT- 4 POMONA 67 /4- Banana Jack T/T4, T5/T6, T7/T8, / 8 Wurth Elektronik 600 DUAL TEST POINT T, T, T9, T0, PWERGD, EN/MODE 6 Wurth Elektronik 600 SINGLE Test Point Post STAND, STAND Keystone 4-40 X / STANDOFF 0 Exar Corporation 5/7 Rev..0.0

6 XRP64 EVALUATION BOARD LAYOUT Fig. : Component Placement Top Side Fig. 4: Bottom Side Fig. 5: Layer Fig. 6: Layer 0 Exar Corporation 6/7 Rev..0.0

7 XRP64 DOCUMENT REVISION HISTORY Revision Date Description.0.0 // Initial release of document BOARD REVISION HISTORY Board Revision Date Description // Initial release of evaluation board FOR FURTHER ASSISTANCE Exar Technical Documentation: EXAR CORPORATION HEADQUARTERS AND SALES OFFICES 4870 Kato Road Fremont, CA 9458 USA Tel.: + (50) Fax: + (50) 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. 0 Exar Corporation 7/7 Rev..0.0