IRDC3065 IRU3065 EVALUATION BOARD USER GUIDE INTRODUCTION SPECIFICATION DATA The IRU3065 controller is designed to provide solutions for the applications requiring low power on board switching regulators. The IRU3065 is specifically designed for positive to negative conversion and uses few components for a simple solution. The IRU3065 operates at high switching frequency (up to 1.5MHz), resulting in smaller components. The output voltage can be set by using an external resistor divider. The stability over all conditions is inherent with this architecture without any compensation. The device is available in the standard 6-Pin SOT-23. Inputs: JP1: Optional VDD input. Default VDD is connected to VCC through a charge pump. JP2: Optional Vref input. If accurate output is re quired, Vref should be connected to a accurate reference voltage JP4: 5V Bus input and Vcc input (default connection). The output voltage will be equal to input voltage with negative sign. (see the IRU3065 data sheet for detailed description). Rev. 1.0 10/20/04 Outputs: JP3. Vout=-5V @200mA. Switching frequency Fs(MAX)=1.2 MHz www.irf.com 1 IRDC3065 SCHEMATIC 1 2 4 3 D D JP4 Vin VIN/VCC R2 GND VGate JP1 R7 VDD R1 Vdd C3 + C U1 GND 1 VGATE VCC C1 + D1 C C4 + Q1 MOSFET P Vcc 6 IRU3065 2 GND VDD VSNS ISNS J1 5 L2 3 JP3 L3 D2 4 Isns Vo JP2 C5 VO C6 R3 + GND GND + VREF/VCC R4 B B Vsns R5 R6 VRef Title A Size A Number Revision A Date: File: 1 2 2-Nov-2004 Sheet of E:\mqiao\IR_dcdc_IC\Iru3065\protel\JE3065~1.DDB Drawn By: 3 4 Figure 1 - Schematic of IRU3065 evaluation-board. Bill of Material (BOM) Ref Designator Q1 U1 D1 D2 L2 C1 C3 C6,C4 R4, R5 R3 R1,R7 R2,R6 L3 C5 JP1,2,3,4 J1 Bumpon 2 Description MOSFET Controller Diode Diode Inductor Ceramic Cap Ceramic Cap Ceramic Cap Resistor Resistor Resistor Resistor Inductor Ceramic Cap Terminal Scope Probe Value PFET Qty Fast Switchinh Fast Switchinh 1.2uA, 2A 1uF, Y5V,16V 100pF, X7R,50V 10uF, X5R, 6.3V 10K, 1%, 0805 0.1Ohm, 0805 Open Short Short Open www.irf.com 1 1 1 1 1 1 1 2 2 1 2 2 1 1 4 1 4 Part# IRLML5203 IRU3065 BAT54 10BQ015 LPO1704-122MC ECJ-2VF1C105Z ECJ-2VC1H100J ECJ2FBOJ106M Any Any Manuf IR IR IR IR Coilcraft Panasonic Panasonic Panasonic Any Any ED1973-ND S1012-02-ND Digi-Key Digi-Key 3M Rev. 1.0 10/20/04 IRDC3065 Layout-Top layer and Bottom layer Rev. 1.0 10/20/04 www.irf.com 3 IRDC3065 Operation Characteristics Vout(V) vs Iout(mA) Efficiency versus load current 6 5 70 4 65 Vout(V) Efficiency(%) 75 60 3 2 55 1 50 0 100 200 300 400 0 0 Iout(mA) Efficiency(%) with diode Efficiency(%) with 100 resistor 200 400 600 800 1000 Iout(mA) Efficiency with 1.2uH inductor, 800k Hz operation Output voltage (absoutle value) versus load curren (Vout=-5V, Iocp=400mA)t Frequency (KHz) versus load current 900 75 800 70 700 Frequency(kHz) Efficiency(%) Efficiency versus load current 65 60 55 50 0 100 200 300 500 400 300 200 400 100 Iout(mA) 0 Efficiency(%) with diode Efficiency(%) with 100ohm resistor 0 200 400 600 800 1000 Iout(mA) Efficiency with 4.7uH inductor, 250kHz operation 4 600 Frequency versus load current. (Vout=-5V, Iocp=400mA)t www.irf.com Rev. 1.0 10/20/04 IRDC3065 Experimental waveforms Operation waveform with 450mA, the boundary of continuous mode and discontinuous mode. The output start out of regulation Start Up Operation waveform at 20mA load. Operation waveform with short output. Operation waveforms with 250mA load (normal operation) Rev. 1.0 10/20/04 www.irf.com 5 IRDC3065 IR WORLD HEADQUARTERS: 233 Kansas St., El Segundo, California 90245, USA Tel: (310) 252-7105 TAC Fax: (310) 252-7903 Visit us at www.irf.com for sales contact information Data and specifications subject to change without notice. 02/01 6 www.irf.com Rev. 1.0 10/20/04