User Guide AN1360 Rev 1.00 ISL8012EVAL1Z: 2A Synchronous Buck Regulator with Integrated MOSFETs Nov 4, 2009 2A Low Quiescent Current 1MHz Features High Efficiency Synchronous Buck High Efficiency Synchronous Buck Regulator with up to 95% Efficiency Regulator 1ms Reset Timer ISL8012 is an integrated power controller rate for the 2A, 1MHz step-down regulator, which is ideal for any low Soft Discharge Output Cap During Enable power, low-voltage application. It is optimized for 2.7V to 5.5V Supply Voltage generating low output voltages down to 0.8V. The supply 3% Output Accuracy Over-Temperature/Load/Line voltage range is from 2.7V to 5.5V, allowing for the use of 2A Guaranteed Output Current a single Li+ cell, three NiMH cells or a regulated 5V input. 25A Quiescent Supply Current in PFM Mode It has a guaranteed minimum output current of 2A. 1MHz pulse-width modulation (PWM) switching Selectable Forced PWM Mode and PFM Mode frequency allows using small external components. It has Less Than 1A Logic Controlled Shutdown Current flexible operation mode selection of forced PWM mode 100% Maximum Duty Cycle for Lowest Dropout and PFM mode with as low as 35A quiescent current for Internal Current Mode Compensation highest light load efficiency to maximize battery life. Internal Digital Soft-Start The ISL8012 includes a pair of low ON-resistance Peak Current Limiting, Short Circuit Protection P-Channel and N-Channel internal MOSFETs to Over-Temperature Protection maximize efficiency and minimize external component count. 100% duty-cycle operation allows less than Enable 400mV dropout voltage at 2A. Small 10 Ld 3mmx3mm DFN The ISL8012 offers a 1ms Power-On-Reset (PG) timer at Pb-Free (RoHS Compliant) power-up. The timer output can be reset by RSI. When shutdown, ISL8012 discharges the output capacitor. Applications Other features include internal digital soft-start, enable for power sequence, overcurrent protection and thermal DC/DC POL Modules shutdown. C/P, FPGA and DSP Power The ISL8012 is offered in a 3mmx3mm 10 Ld DFN Plug-in DC/DC Modules for Routers and Switchers package with 1mm maximum height. The complete PGtable Instruments 2 converter occupies less than 1cm area. Test and Measurement Systems Ordering Information Pinout PART TEMP. ISL8012 NUMBER PART RANGE PACKAGE PKG. (10 LD DFN) (Notes 1, 2, 3) MARKING (C) (Pb-Free) DWG. TOP VIEW ISL8012IRZ 012Z -40 to +85 10 Ld 3x3 DFN L10.3x3C NOTES: VIN 1 10 LX 1. Add -T or suffix for tape and reel. Please refer to TB347 for details on reel specifications. VCC 2 9 PGND 2. These Intersil Pb-free plastic packaged products employ EN 3 8 SGND special Pb-free material sets, molding compounds/die attach materials, and 100% matte tin plate plus anneal (e3 PG 4 7 VFB termination finish, which is RoHS compliant and compatible with both SnPb and Pb-free soldering operations). Intersil 6 RSI 5 MODE Pb-free products are MSL classified at Pb-free peak reflow temperatures that meet or exceed the Pb-free requirements of IPC/JEDEC J STD-020. 3. For Moisture Sensitivity Level (MSL), please see device information page for ISL8012. For more information on MSL please see techbrief TB363. AN1360 Rev 1.00 Page 1 of 7 Nov 4, 2009ISL8012EVAL1Z: 2A Synchronous Buck Regulator with Integrated MOSFETs Evaluating the Other Output Voltage Whats Inside The ISL8012EVAL1Z kit output is preset to 1.8V The Evaluation Board Kit contains the following however, output voltages can be adjusted from 0.8V materials: to 3.3V using Equations 1 and 2: The ISL8012EVAL1Z REVC Board R 1 (EQ. 1) VOUT 0.8 1 ------- = + The ISL8012 Data Sheet R 2 This EVAL KIT Application Note Lets set R = 100k 2 Recommended Equipment VOUT (EQ. 2) ------------------ R = R 1 1 2 0.8 The following materials are recommended to perform testing: If the desired output is 0.8V, short R and open R . 1 2 0V to 10V power supply with at least 3A source Mode Control current capability, battery and notebook AC The ISL8012 has a MODE pin that controls the adapter operation mode. When the MODE pin is driven to low Two electronic loads capable of sinking current up or shorted to ground, the regulator operates in a forced to 5A PWM mode. The forced PWM mode remains the fixed PWM frequency at light load instead of entering the Digital multimeters (DMMs) skip mode. 100MHz quad-trace oscilloscope TABLE 1. SWITCH SETTINGS Signal generator SW2 SKIP FUNCTION Quick Setup Guide PWM Fixed PWM Frequency at Light Load 1. Ensure that the circuit is correctly connected to the supply and loads prior to applying any power. PFM Force Continuous Mode 2. Connect the bias supply to VIN, the plus terminal to P4 (VIN) and the negative return to P5 (GND). SW1 ENABLE ON/OFF CONTROL 3. Verify that SW1 is in the ON position. OFF Disable V 4. Turn on the power supply. OUT ON Enable V 5. Verify the output voltage is 1.8V for V OUT OUT AN1360 Rev 1.00 Page 2 of 7 Nov 4, 2009