AP65200-EVM 340kHz 18V 2A Synchronous DC/DC Buck Converter Description The AP65200 is a 340kHz switching frequency externally compensated synchronous DC/DC buck converter. It has integrated low RDSON high- and low-side MOSFETs. The AP65200 enables continues load current of up to 2A with efficiency as high as 96%. The AP65200 features current mode control operation, which enables fast transient response times and easy loop stabilization. The AP65200 implements an automatic custom light load efficiency improvement algorithm. The AP65200 is available in green industry standard SO-8, SO-8EP, U-DFN2626-10 and MSOP-8EP package. The evaluation board utilizes only the footprint of the SO-8 and SO-8EP package. • Gaming Consoles • TV Sets and Monitors • Set Top Boxes Performance Spec of AP65200S-EVM Parameter Input voltage Output Current Output Voltage Output Voltage Ripple Transient Response • Distributed Power Systems • Home Audio • Consumer Electronics Conditions Range 4.75V to 18V Performance Value 12V 2A 3.3V 20mVp-p 140mV Peak Deviation Load step 1.0A/us to 2A/us Switching Frequency Efficiency 340kHz 93% Figure 1. Evaluation Board Figure 2. Efficiency vs Load Current Efficiency Vs Load Current Vout=3.3V 100 Efficiency (%) 95 90 5Vin 12Vin 18Vin 85 80 75 70 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 Load Current (A) AP65200 Document number: Rev. 1 - 0 1 of 4 www.diodes.com January 2013 © Diodes Incorporated AP65200-EVM 340kHz 18V 2A Synchronous DC/DC Buck Converter Quick Start Guide The AP65200-EVM has a simple layout and allows access to the appropriate signals through test points. To evaluate the performance of the AP65200, follow the procedure below: 1. Connect a power supply to the input terminals Vin and GND. Set Vin to 12V. 2. Connect the positive terminal of the electronic load to Vout and negative terminal to GND. 3. EN has a positive voltage through a 100K pull-up to Vin. No supply input is required for EN. Note: To use the EN function drive EN above 1.3V to start the converter and below 0.4V to stop the converter. 4. The evaluation board should now power up with a 3.3V output voltage. 5. Check for the proper output voltage of 3.3V(+/-1%) at the output terminals Vout and GND. Measurement can also be done with a multimeter with the positive and negative leads between Vout and GND. 6. Set the load to 1.5A through the electronic load. Check for the stable operation of the SW signal on the oscilloscope. Measure the switching frequency. A test point is conveniently located at the head of the inductor. Measurement/Performance Guidelines: 1) The evaluation board has the inductor pad spaced for easy access to measure the inductor current. As shown in the picture, a current probe can be connected to the wire loop to measure the inductor current. 2) When measuring the output voltage ripple, maintain the shortest possible ground lengths on the oscilloscope probe. Long ground leads can erroneously inject high frequency noise into the measured ripple. 3) For efficiency measurements, connect an ammeter in series with the input supply to measure the input current. Connect an electronic load to the output for output current. AP65200 Document number: Rev. 1 - 0 2 of 4 www.diodes.com January 2013 © Diodes Incorporated AP65200-EVM 340kHz 18V 2A Synchronous DC/DC Buck Converter EVALUATION BOARD SCHEMATIC EN R4 100kΩ 1 BS SS 8 C6 0.1µF C1 10nF 2 VIN 4.75V TO 18V IN EN C7 OPEN R5 OPEN 7 AP65200 C2 10µF 3 C8 OPEN SW COMP 6 C3 6.8nF 4 GND FB C4 OPEN 5 R1 26.1kΩ 1% R3 10kΩ 1% R2 6.8kΩ SW L1 10µH D1 OPEN C5 22µF VOUT 3.3V C9 22µF BILL OF MATERIALS REF VALUE DESCRIPTION PACKAGE MANUFACTURER MANUFACTURER P/N C1 10nF SM0805 AVX 08055C103KAT2A C5, C9 C3 22uF 1210 AVX 1210YD226KAT2A SM0805 AVX 08055C682KAT2A C2 10uF 1210 AVX 12103D106KAT2A C6 0.1uF 0805 AVX 08055C104KAT2A L1 10µh Ceramic Capacitor, 25V,X5R Ceramic Cap, 16V, X5R Ceramic Cap, 50V, X7R Ceramic Capacitor, 10V, X5R Ceramic Cap, 50V, X7R Inductor, 5.0A SMD Wurth Electronics 74477110 R1 26.1K Resistor, 1% 0603 Panasonic CRCW060326KIFKEA R2 6.8KΩ Resistor, 1% 0603 Panasonic ERJ-6GEYJ682V R3 10.0k Resistor, 1% 0603 Panasonic ERJ-6ENF1002V R4 100k Resistor, 1% 0603 Panasonic ERJ-6GEYJ104V DC/DC Converter SO-8EP Diodes Inc AP65200SP 6.8nF U1 AP65200 Document number: Rev. 1 - 0 3 of 4 www.diodes.com January 2013 © Diodes Incorporated AP65200-EVM 340kHz 18V 2A Synchronous DC/DC Buck Converter Top Layer Bottom Layer AP65200 Document number: Rev. 1 - 0 4 of 4 www.diodes.com January 2013 © Diodes Incorporated