ISL8009AEVAL1Z Renesas

USERS MANUAL ISL8009AEVAL1Z AN1388 Rev 1.00 1.5A Synchronous Buck Regulator with Integrated MOSFETs October 9, 2008 Description Quick Setup Guide 1. Ensure that the circuit is correctly connected to the supply The ISL8009AEVAL1Z kit is intended for use by individuals and loads prior to applying any power. with requirements for Point-of-Load applications sourcing 2. Connect the bias supply to VIN. Plus terminal to P4(VIN) from 2.7V to 5.5V. The ISL8009EVAL1Z evaluation board and negative return to P5(GND). demonstrates the performance of the ISL8009A low quiescent current mode converter. 3. Verify that position is ON for SW1. 4. Turn on the power supply. The ISL8009A is offered in a 2mmx3mm 8 Ld DFN package with 1mm maximum height. The complete converter 5. Verify the output voltage is 1.8V for V OUT 2 occupies less than 1cm area. Evaluating the Other Output Voltage The ISL8009AEVALIZ kit output is preset to 1.8V however, Key Features output voltages can be adjusted from 0.8V to 3.3V by High Efficiency Synchronous Buck Regulator With up to following Equations 1 and 2: 95% Efficiency R 1 (EQ. 1) 2ms Reset Timer V 0.8 1 ------- = + OUT R 2 Soft Discharge Output Cap During Disable Lets set R = 124k : 1 2.7V to 5.5V Supply Voltage R 1 R = ------------------------------- 3% Output Accuracy Over-Temperature/Load/Line 2 V (EQ. 2) OUT ---------------- 1 0.8 1.5A Guaranteed Output Current 17A Quiescent Supply Current in PFM Mode If desired output is 0.8V then short R and open R . 1 2 Selectable Forced PWM Mode and PFM Mode Mode Control Less Than 1A Logic Controlled Shutdown Current The ISL8009A has a SKIP pin that controls the operation mode. When the SKIP pin is driven to low or shorted to 90% Maximum Duty Cycle for Lowest Dropout ground, the regulator operates in a forced PWM mode. The Internal Current Mode Compensation forced PWM mode remains the fixed PWM frequency at light load instead of entering the skip mode. Internal Digital Soft-Start TABLE 1. SWITCH 1 SETTINGS Peak Current Limiting, Short Circuit Protection SW1 SKIP FUNCTION Over-Temperature Protection 1 PWM Fixed PWM frequency at light load Enable 3 PFM Force continuous mode Small 8 Ld 2mmx3mm DFN Pb-Free (RoHS Compliant) SW2 ENABLE ON/OFF CONTROL Recommended Equipment 1 OFF Disable V OUT The following materials are recommended to perform 3 ON Enable V OUT testing: 0V to 10V power supply with at least 5A source current capability, battery, notebook AC adapter Two electronic loads capable of sinking current up to 5A Digital Multimeters (DMMs) 100MHz quad-trace oscilloscope Signal generator AN1388 Rev 1.00 Page 1 of 6 October 9, 2008ISL8009AEVAL1Z Schematic 1 J1 534 1 J2 2 54 3 A U1 L1 2.2H 1 1 VIN 1 5 1 P4 RSI VIN RSI P7 2 6 1 1 EN EN VFB 3 7 2 1 POR POR GND 4 8 C5 C6 SKIP SKIP LX 1 1 C4 10F E 10F R1 A 220pF 124k C1 C2 ISL8009AIRZ-T 9 2 2 10F 10F P8 1 2 A 22 2 A 1 P5 R2 100k A 1 A 1 RSI 1 P1 R3 100k A VIN VIN 2 2 VIN R6 R7 100k 100k 2 R5 1 1 3 3 2k PFM 2 SKIP 2 EN ON/EX 2 2 SW2 SW1 1 21 PWM OFF 2 1 1 R4 1 1 100k P2 D1 P6 D 2 1 2 31 2N7002 R9 R8 1 PG 1 Q1 OPEN OPOPENEN P3 1 1 2 A A A AN1388 Rev 1.00 Page 2 of 6 October 9, 2008 1 2 22 31 1 2 9 4 3 2 1 5 4 3