USERS MANUAL ISL8117DEMO3Z UG058 Rev 0.00 Demonstration Board User Guide November 24, 2015 Description Key Features The ISL8117DEMO3Z demonstration board (shown in Figure 4) Small, compact design features the ISL8117. The ISL8117 is a 60V high voltage Wide input range: 4.5V to 60V synchronous buck controller that offers external soft-start, High light-load efficiency in pulse skipping DEM operation independent enable functions and integrates UV/OV/OC/OT protection. Its current mode control architecture and internal Programmable soft-start compensation network keep peripheral component count Optional DEM/CCM operation minimal. Programmable switching frequency ranging from Supports prebias output with SR soft-start 100kHz to 2MHz helps to optimize inductor size while the strong gate driver delivers up to 30A for the buck output. External frequency sync PGOOD indicator Specifications OCP, OVP, OTP, UVP protection The ISL8117DEMO3Z demonstration board is designed for high current applications. The current rating of the ISL8117DEMO3Z References is limited by the FETs and inductor selected. The electrical ISL8117 datasheet ratings of ISL8117DEMO3Z are shown in Table 1. TABLE 1. ELECTRICAL RATINGS Ordering Information PARAMETER RATING Input Voltage 4.5V to 60V PART NUMBER DESCRIPTION Switching Frequency 300kHz ISL8117DEMO3Z High voltage PWM step-down synchronous buck controller Output Voltage 3.3V Output Current 6A OCP Set Point Minimum 8A at ambient room temperature VIN VOUT LGATE/OCS UGATE ISL8117 MOD/SYNC VCC5C EN DISABLE CCM DEM FIGURE 1. ISL8117DEMO3Z BLOCK DIAGRAM UG058 Rev 0.00 Page 1 of 10 November 24, 2015ISL8117DEMO3Z Evaluating the Other Output Voltages Recommended Testing The ISL8117DEMO3Z output is preset to 3.3V, however, the Equipment output can be adjusted from 1.8V to 5V. The output voltage The following materials are recommended to perform testing: , will depend on the desired output programming resistor, R 2 voltage of the regulator and the value of the feedback resistor 0V to 60V power supply with at least 10A source current R , as shown in Equation 1. 1 capability 0.6 (EQ. 1) Electronic loads capable of sinking current up to 10A ------------------------------ R = R 2 1 V 0.6 OUT Digital Multimeters (DMMs) Table 2 shows the component selection that should be used for 100MHz quad-trace oscilloscope the respective V of 1.8V, 3.3V and 5V. OUT Quick Test Guide TABLE 2. EXTERNAL COMPONENT SELECTION 1. Ensure that the circuit is correctly connected to the supply and V R OUT 2 electronic loads prior to applying any power. Please refer to (V) (k ) Figure 3, on page 3 for proper setup. 1.8 24.9 2. Turn on the power supply. 3.3 11 3. Adjust input voltage V within the specified range and IN 56.8 observe output voltage. The output voltage variation should be within 3%. 4. Adjust load current within the specified range and observe PCB Layout Guidelines output voltage. The output voltage variation should be Careful attention to layout requirements is necessary for within 3%. successful implementation of an ISL8117 based DC/DC 5. Use an oscilloscope to observe output voltage ripple and converter. The ISL8117 switches at a very high frequency and phase node ringing. For accurate measurement, please refer therefore the switching times are very short. At these switching for proper test setup. to Figure 2 frequencies, even the shortest trace has significant impedance. Also, the peak gate drive current rises significantly in an extremely short time. Transition speed of the current from one device to another causes voltage spikes across the interconnecting impedances and parasitic circuit elements. These voltage spikes can degrade efficiency, generate EMI and OUTPUT CAP increase device overvoltage stress and ringing. Careful OUTOUTPPUTUT CAP CAP OR MOSFET component selection and proper PC board layout minimizes the OR OR MMOSFOSFEETT magnitude of these voltage spikes. There are three sets of critical components in a DC/DC converter FIGURE 2. PROPER PROBE SETUP TO MEASURE OUTPUT RIPPLE using the ISL8117: AND PHASE NODE RINGING The controller Functional Description The switching power components The ISL8117DEMO3Z is a compact design with high efficiency and high power density. The small signal components The switching power components are the most critical from a As shown in Figure 3 on page 3, 4.5V to 60V V is supplied to J1 IN layout point of view because they switch a large amount of (+) and J2 (-). The regulated 3.3V output on J3 (+) and J5 (-) can energy, which tends to generate a large amount of noise. The supply up to 6A to the load. critical small signal components are those connected to sensitive nodes or those supplying critical bias currents. A multilayer Operating Range printed circuit board is recommended. The input voltage range is from 4.5V to 60V for an output voltage of 3.3V. The rated load current is 6A with the OCP point set at a minimum 8A at room temperature ambient conditions. The ISL8117 has an operating temperature range of -40C to +125C. Please note that airflow is needed. UG058 Rev 0.00 Page 2 of 10 November 24, 2015