ISL9444EVAL1Z Renesas

USERS MANUAL ISL9444EVAL1Z AN1712 Rev 0.00 Triple PWM Step-Down Synchronous Buck Controller December 22, 2011 ISL9444EVAL1Z Evaluation Electrical Rating Board The ISL9444EVAL1Z evaluation board is designed for low current application. The current rating of the ISL9444EVAL1Z The ISL9444EVAL1Z evaluation board (shown in Figure 1) is limited by the FETs and inductors selected. The ISL9444 features the ISL9444. The ISL9444 is a triple-output gate drivers are capable of delivering up to 25A for each PWM synchronous buck controller that integrates three PWM channel as long as the proper FETs and inductors are provided. controllers. The ISL9444 offers external soft-start, The electrical ratings of ISL9444EVAL1Z are shown in Table 1. independent enable functions and integrates UV/OV/OC/OT protection. Its current mode control architecture and internal TABLE 1. ELECTRICAL RATING compensation network keep peripheral component count PARAMETER RATING minimal. Programmable switching frequency ranging from 200kHz to 1200kHz helps to optimize inductor size while the Input Voltage 6V-20V strong gate drivers deliver up to 25A for each PWM channel. Switching Frequency 600kHz PWM1 Output 1.05V max 6A PWM2 Output 3.3V max 6A PWM3 Output 1.8V max 6A FIGURE 1. ISL9444EVAL1Z EVALUATION BOARD AN1712 Rev 0.00 Page 1 of 11 December 22, 2011ISL9444EVAL1Z TABLE 2. Whats Inside JUMPER The Evaluation Board Kit contains the following materials: POSITION FUNCTION The ISL9444EVAL1Z J3 EN (Pin 1-2) Enable PWM1 when VCC5V is ready. The ISL9444 datasheet DIS (Pin 2-3) Disable PWM1 This EVAL KIT document J4 PG1 (Pin 1-2) Enable PWM2 when PGOOD1 is high. If this option is chosen, PWM2 will be enabled after Recommended Testing PWM1 finishes start-up. Equipment GND (Pin 3-4) Disable PWM2 The following materials are recommended to perform testing: PFO Enable PWM2 when PFI is high. In the (Pin 5-6) ISL9444EVAL1Z, PFI is connected to the input 0V to 20V Power Supply with at least 10A Source Current voltage through a resistor divider. If this Capability option is chosen, PWM2 will be enabled when Three Electronic Loads Capable of Sinking Current up to 7A the input voltage is around 6.4V Digital Multimeters (DMMs) J6 EN2 (Pin 1-2) Enable PWM3 when EN2 is high. In this option, PWM3 is tracking with PWM2. 100MHz Quad-Trace Oscilloscope GND (Pin 3-4) Disable PWM3 Quick Test Guide VCC5V Enable PWM3 when VCC5V is ready. (Pin 5-6) 1. ISL9444 has a total of three PWM outputs. Jumpers J3, J4 and J6 provide rich options to control these three PWM outputs. Please refer to Table 2 for the desired operating option. The default option is to enable PWM1 when VCC5V is ready and then enable PWM2 and PWM3 simultaneously after PWM1 finishes start-up (i.e., PGOOD1 is high). 2. Ensure that the circuit is correctly connected to the supply and electronic loads prior to applying any power. Please refer to Figure 2 for proper set-up. 3. Turn on the power supply. 4. Adjust input voltage VIN within the specified range and observe output voltage. The output voltage variation should be within 3%. 5. Adjust load current within the specified range and observe output voltage. The output voltage variation should be within 3%. 6. Use an oscilloscope to observe output voltage ripple and Phase node ringing. For accurate measurement, please refer to Figure 3 for proper test set-up. AN1712 Rev 0.00 Page 2 of 11 December 22, 2011