USERS MANUAL ISL8130EVAL3Z AN1771 Rev 1.00 Evaluation Board - Sepic Converter August 7, 2012 Introduction Features ISL8130EVAL3Z is a sepic converter, which features the Operates From: universal PWM controller, ISL8130. The evaluation board - 4.5V to 5.5V Input for 5V Input delivers 10V output at 2A. All the necessary components are - 5.5V to 16V Input within the 1.78 x 1.24 PCB area. Resistor-Selectable Switching Frequency from 100kHz to The ISL8130 is designed to drive N-Channel MOSFETs in a 1.4MHz synchronous rectified buck topology for up to 25A instant MOSFET current and can be configured for boost, buck/boost Voltage Margining and External Reference Tracking Modes and sepic converters as well. The ISL8130 integrates control, Kelvin Current Sensing output adjustment, monitoring and protection functions into a - Upper MOSFET r for Current Sensing for Buck and DS(ON) single package. The ISL8130 provides simple, voltage mode Buck/Boost Converter control with fast transient response. - Precision Resistor/Inductor DCR for Boost and Sepic This application note describes how to use the ISL8130 to Converter generate V from power supply of voltage either higher or OUT lower than the V . Extensive Protection Functions: OUT - Overvoltage, Overcurrent, Undervoltage Evaluation Board Specifications Power Good Indicator TABLE 1. EVALUATION BOARD ELECTRICAL SPECIFICATIONS SPEC DESCRIPTION MIN TYP MAX UNIT V Board Input Range 5.6 10 16 V IN IOC Input Current 5 A V I = 0A 9.5 10 10.5 V OUT OUT I V = 5.6V 2 A OUT IN V = 5.6V, IOUT = 2A 88.6 % IN V = 8.4V, IOUT = 2A 90.3 % IN Recommended Equipment The following equipment is recommended for evaluation: 0V to 20V power supply with 10A source current capability Electronic load capable of sinking 2A 20V Digital Multi meters (DMMs) 100MHz Quad-Trace Oscilloscope FIGURE 1. ISL8130EVAL3Z TOP VIEW TABLE 2. RECOMMENDED COMPONENT SELECTION FOR QUICK EVALUATION INDUCTOR (L, ISAT V R4 V I MEASURED IN OUT IN OUT (V) (k ) (V) (A) F (kHz)/R (k ) MOSFET FORWARD DIODE PARALLEL) SW 5 7 9.53 5.6 to 14 2 500kHz/28.7k BSO051N03 MS SL43 4.7H, 6A 10 6.34 5.6 to 16 2 500kHz/28.7k BSC059N04 LS SL42 4.7H, 7A 12 5.23 5.6 to 14 2 500kHz/28.7k BSC057N03 LS SL42 4.7H, 9A NOTES: 1. Please select the output capacitor with a voltage rating higher than the output. 2. Please contact Intersil Sales for assistance. AN1771 Rev 1.00 Page 1 of 10 August 7, 2012ISL8130EVAL3Z FIGURE 2. ISL8130EVAL3Z TEST SET-UP Probe Set-up Quick Test Setup 1. Ensure that the Evaluation board is correctly connected to the power supply and the electronic load prior to applying any power. Please refer to Figure 2 for proper set-up. 2. Leave JP3 in the open position. 3. Turn on the power supply V < 16V. IN OUTPUT CAP OUTOUTPPUTUT CAP CAP 4. Adjust input voltage V within the specified range and IN OR MOSFET OR OR MMOSFOSFEETT observe output voltage. The output voltage variation should be within 5%. FIGURE 3. OSCILLOSCOPE PROBE SET-UP 5. Adjust load current within 2A. The output voltage variation should be within 5%. 6. Use oscilloscope to observe output ripple voltage and phase VOUT Setting node ringing. For accurate measurement, please refer to The output voltage is set by the resistor divider, R and R . 4 1 Figure 3 for proper probe set-up. R + R 4 1 7. Optimization. Please refer to Table 2 on page 1 for (EQ. 1) -------------------- V = 0.6V OUT R optimization recommendation. 4 8. For 5V input applications, please tie the VCC5V to VIN and do Resistor R is a resistor jumper for loop gain measurement. It is 11 not allow V to go above 5.5V. IN recommended to set R = 50 for loop gain measurement. 11 NOTE: Test points: VIN+, VIN-, VO+ and VO- are for voltage measurement only. Do not allow high current through these test points. Component Selection Component Voltage Stress The controller, ISL8130, the input capacitors and the flying capacitors, C18 and C19, see the input voltage. MOSFET and forward diode see the voltage stress of V + V . IN OUT Duty Cycle Calculation The duty cycle of the sepic converter can be estimated using Equation 2. V + V OUT F (EQ. 2) D = ---------------------------------------- V++V V IN OUT F Where: V is the forward voltage of the diode, D1. F AN1771 Rev 1.00 Page 2 of 10 August 7, 2012