USERS MANUAL lSL8272MEVAL1Z UG003 Rev 0.00 Evaluation Board User Guide September 17, 2014 Description Key Features The ISL8272M is a 50A step-down DC/DC power supply V range of 4.5V to 14V, V adjustable from 0.6V to 5V IN OUT module with an integrated digital PWM controller, dual-phase Programmable V , margining, input and output UVP/OVP, OUT synchronous power switches, inductors and passives. Only I limit, OTP/UTP, soft-start/stop, sequencing, and OUT input output capacitors and minimal passives are needed to external synchronization finish the design. 50A of continuous output current can be Monitor: V , V , I , temperature, duty cycle, switching IN OUT OUT delivered without a need of airflow or heatsink. The ISL8272M frequency and faults uses ChargeMode control (ASCR) architecture, which responds to a transient load within a single switching cycle. ChargeMode control tunable with PMBus Mechanical switch for enable and power-good LED indicator The ISL8272MEVAL1Z evaluation board is a 4.7in x 4.8in 6-layer FR4 board with 2oz. copper in all layers. This evaluation board comes with placeholders for pin-strap resistor Specifications population to adjust output voltage, switching frequency, soft- This board has been configured for the following operating start/stop timing and input UVLO threshold, ASCR gain and conditions by default: residual parameters and device PMBus address. More configurations, such as sequencing, Digital-DC (DDC) bus V = 5V to 12V IN configuration and fault limits can be easily programmed or V = 1.2V OUT changed via PMBus compliant serial bus interface. I = 50A MAX ZLUSBEVAL3Z (USB to PMBus adapter) is provided with this f = 421kHz evaluation kit, which connects the evaluation board to a PC to SW activate the PMBus communication interface. The PMBus Peak efficiency: >90.5% at 70% load command set is accessed by using the PowerNavigator Output ripple: <10mV P-P evaluation software from a PC running Microsoft Windows. ASCR gain = 200, ASCR residual = 90 References On/off delay = 5ms On/off ramp time = 5ms ISL8272M datasheet Ordering Information PART NUMBER DESCRIPTION ISL8272MEVAL1Z ISL8272M Kit (Evaluation Board, ZLUSBEVAL3Z Adapter, USB Cable) PGOOD LED INTERCONNECTS DDC AND SYNC INTERCONNECTS DDC AND ENABLE SWITCH BETWEEN BOARDS SYNC BETWEEN BOARDS TO DAISY CHAIN PMBus CONNECT TO ZLUSBEVAL3Z CONNECTION DONGLE. FOR MULTIPLE BOARD EVALUATION, CONNECT TO PMBus DONGLE OUT CONNECTION OF OTHER BOARD VOUT REGULATION MONITOR FIGURE 1. TOP SIDE UG003 Rev 0.00 Page 1 of 15 September 17, 2014lSL8272MEVAL1Z RESISTOR PLACEHOLDERS FIGURE 2. BOTTOM SIDE 3. Connect power supply to VIN connectors (J5 and J6). Make Recommended Equipment sure power supply is not enabled when making connection. DC power supply with minimum 15V/25A sourcing capacity 4. Turn power supply on. Electronic load capable of sinking current up to 50A 5. Set ENABLE switch to ENABLE. Digital multimeters (DMMs) 6. Measure 1.2V VOUT at probe point labeled VOUT REGULATION MONITOR (J11). Oscilloscope with higher than 100MHz bandwidth 7. Observe switching frequency of 421kHz at probe points labeled PHASE1 (TP10) and PHASE2 (TP11). Functional Description 8. To measure the module efficiency, connect the multimeter The ISL8272MEVAL1Z provides all circuitry required to evaluate voltage probes at probe points labeled VIN (TP1), GND the features of the ISL8272M. A majority of the features of the (TP2) and VOUT (TP12). ISL8272M, such as compensation-free ChargeMode control, 9. To change VOUT, disconnect board from the setup and soft-start delay and ramp times, supply sequencing, and voltage populate a 1% standard 0603 resistor at RVSET placeholder margining are available on this evaluation board. For sequencing location on bottom layer. Refer to the Output Voltage evaluation, the board can be connected to any Intersil digital Resistor Settings table in the ISL8272M datasheet for module evaluation board that supports the DDC bus. recommended values. By default, VOUT MAX is set to 110% Figures 1 and 2 show the board images of the ISL8272MEVAL1Z of VOUT set by pin-strap resistor. evaluation board. 10. To change switching frequency, disconnect board from the setup and populate a 1% standard 0603 resistor at RFSET Quick Start Guide placeholder location on bottom layer. Refer to the Switching Frequency Resistor Settings table in the ISL8272M Pin-Strap Option datasheet for recommended values. ISL8272MEVAL1Z can be configured in pin-strap mode with 11. To change soft-start/stop delay and ramp time, disconnect standard 1% 0603 resistors. PMBus interface is not required to board from the setup and populate a 1% standard 0603 evaluate ISL8272M in pin-strap mode. Output voltage (V ), OUT resistor at R6 placeholder location on bottom layer. Refer to switching frequency (f ), soft-start/stop delay and ramp time, SW the Soft Start/Stop Resistor Settings table in the ISL8272M input undervoltage protection (UVLO) threshold, ASCR gain and datasheet for recommended values. residual, and device PMBus address can be changed by 12. To change UVLO, disconnect board from the setup and populating recommended resistors at placeholders provided in populate a 1% standard 0603 resistor at R6 placeholder the evaluation board. By default, the evaluation board operates location on bottom layer. Refer to the UVLO Resistor Settings in pin-strap mode and regulates at V = 1.2V, f = 421kHz, OUT SW table in the ISL8272M datasheet for recommended values. soft-start/stop delay time = 5ms, soft-start/stop ramp Notice that the UVLO programming shares the same pin with time = -5ms, UVLO = 4.5V, ASCR gain = 200, ASCR residual = 90 soft-start/stop programming. and PMBus address = 28h. Follow these steps to evaluate ISL8272M in pin-strap mode. 13. To change ASCR gain and residual, disconnect board from the setup and populate a 1% standard 0603 resistor at R7 1. Set ENABLE switch to DISABLE. placeholder location on bottom layer. Refer to the ASCR 2. Connect Load to VOUT lug connectors (J7-J8 and J9-J10). UG003 Rev 0.00 Page 2 of 15 September 17, 2014