AP6507-EVM 500kHz 18V 3A Synchronous DCDC Buck Converter Description The AP6507 is a 500kHz switching frequency internal compensated synchronous DC/DC buck converter. It has integrated compensation, and low RDSON high- and low-side MOSFETs. The AP6507 is available in a standard Green SOP-8L-EP with exposed pad for improved thermal performance and is RoHS compliant. The AP6507 features current-mode control operation, which enables fast transient response times and easy loop stabilization. • Gaming Consoles • TV sets and Monitors • Set Top Boxes Performance Spec of AP6507SPG-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 Peak Deviation Load step 1.5A/us to 3A/us Switching Frequency Efficiency Figure 1. Evaluation Board Performance Value 12V 3A 1.2V 20mVp-p 70mV 500kHz 90% Figure 2. Efficiency vs Load Current Quick Start Guide AP6507 Document number: Rev. 1 - 0 1 of 4 www.diodes.com May 2011 © Diodes Incorporated AP6507-EVM 500kHz 18V 3A Synchronous DCDC Buck Converter The AP6507SPG-EVM has a simple layout and allows access to the appropriate signals through test points. To evaluate the performance of the AP6507, 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. AP6507 will automatically power up through the resistor dividor that connects EN to Vin. This is only valid when Vin =6.5V to 18V. 4. For Vin =4.5V to 6.5V, Connect a power supply to EN and GND. Set EN=3V. *DO NOT increase the voltage to EN > 5V, as it will damage the part. a. To use the EN function drive EN above 1.3V to start the converter and below 0.4V to stop the converter. 5. The evaluation board should now power up with a 1.2V output voltage. 6. Check for the proper output voltage of 1.2V(+/-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. 7. 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. AP6507 Document number: Rev. 1 - 0 2 of 4 www.diodes.com May 2011 © Diodes Incorporated AP6507-EVM 500kHz 18V 3A Synchronous DCDC Buck Converter EVALUATION BOARD SCHEMATIC BILL OF MATERIALS QTY REF VALUE DESCRIPTION PACKAGE MANUFACTURER MANUFACTURER P/N 12103D226KAT2A 1 C1 22uF 1210 AVX 2 C2 47uF 1210 AVX 3 0.1uF 0603 TDK GRM32ER61A476 KE20L C1608X7R1H104M 5 C3, C4 L1 3.3uH Ceramic Capacitor, 25V,X5R Ceramic Capacitor, 10V, X5R Ceramic Capacitor, 50V, X7R Inductor, 5.3A SMD Wurth Electronics 7440650033 6 R1 4.99k Resistor, 1% 0603 Panasonic ERJ-3EKF4991V 7 R2 10.2k Resistor, 1% 0603 Panasonic ERJ-3EKF1022V 8 R3 24.9k Resistor, 1% 0603 Panasonic ERJ-3EKF2492V 9 R4 100k Resistor, 1% 0603 Panasonic ERJ-3EKF1003V 10 R5 24.9k Resistor, 1% 0603 Panasonic ERJ-3EKF2492V 11 U1 DC/DC Converter SOP-8LEP Diodes Inc AP6507 AP6507 Document number: Rev. 1 - 0 3 of 4 www.diodes.com May 2011 © Diodes Incorporated AP6507-EVM 500kHz 18V 3A Synchronous DCDC Buck Converter TOP SILK LAYER TOP LAYER BOTTOM LAYER AP6507 Document number: Rev. 1 - 0 4 of 4 www.diodes.com May 2011 © Diodes Incorporated