PAM2305D EVB User Guide PAM2305D DFN EV Board User Guide AE Department 1. Revision Information Date 2011/07 Revision V1.0 Description Initial Release Comment 2. PAM2305D General Description The PAM2305D is a step-down current-mode, DC-DC converter. At heavy load, the constant frequency PWM control performs excellent stability and transient response. To ensure the longest battery life in portable applications, the PAM2305D provides a power-saving Pulse-Skipping Modulation (PSM) mode to reduce quiescent current under light load operation to save power. The PAM2305D supports a range of input voltages from 2.5V to 5.5V, allowing the use of a single Li+/Lipolymer cell, multiple Alkaline/NiMH cell, USB, and other standard power sources. The output voltage is adjustable from 0.6V to the input voltage. All versions employ internal power switch and synchronous rectifier to minimize external part count and realize high efficiency. During shutdown, the input is disconnected from the output and the shutdown current is less than 0.1µA. Other key features include under-voltage lockout to prevent deep battery discharge. The PAM2305D is available in SOT23-5, DFN2x2 6-Pin and QFN3x3 16-Pin packages. This application note contains new product information. Diodes, Inc. reserves the right to modify the product specification without notice. No liability isassumed as a result of the use of this product. No rights under any patent accompany the sale of the product. PAM2305D EVB User Guide 3. Key Features Efficiency up to 96% Only 40uA(TYP.) Quiescent Current Output Current: Up to 1A Internal Synchronous Rectifier 1.5MHz Switching Frequency Soft Start z z z z z z Under-Voltage Lockout Short Circuit Protection Thermal Shutdown 5-pin Small SOT23-5, DFN2x2 6-Pin and QFN3x3 16-Pin Packages Pb-Free Package z z z z z 4. EV Board Schematic 1 EN Vin 2 1 3 EN 2 Vin Vin 3 NC FB EN GND Vin C1 SW 6 FB 5 4 L1 Vout R1 C3 FB C2 R2 5. EVB PAM2305D EB26AA Description PAM2305D DFN EB26AA is an evaluation board for the PAM2305D DFN, a DC/DC converter. The board is targeted to be used in providing a simple and convenient evaluation environment for the PAM2305D. Requires parts, power supply connectors etc. on the board, which makes it easy to be evaluated. . This application note contains new product information. Diodes, Inc. reserves the right to modify the product specification without notice. No liability isassumed as a result of the use of this product. No rights under any patent accompany the sale of the product. PAM2305D EVB User Guide 6. EV Board View Top View 7. Resistor Select for Output Voltage Setting VOUT = (1+R1/R2)×VREF Vo 1.2V 1.5V 1.8V 2.5V 3.3V R3 150k 150k 300k 475k 680k (VREF = 0.6V) R4 150k 100k 150k 150k 150k L 1.0µH 2.2µH 2.2µH 4.7µH 4.7µH This application note contains new product information. Diodes, Inc. reserves the right to modify the product specification without notice. No liability isassumed as a result of the use of this product. No rights under any patent accompany the sale of the product. PAM2305D EVB User Guide 8. External Compnents Selection Input & output Capacitors (C1, C2) (1) For lower output ripple, low ESR is required. (2) Low leakage current needed, X5R/X7R ceramic recommend, multiple capacitor parallel connection. Feed forward capacitor (C3) (1) Lower the output ripple. (2) Low leakage current needed, 100pF, COH/CH ceramic recommend. Output Voltage programmer resistors (R1, R2) (1) For programmer output voltage. (2) For accurate output voltage, 1% tolerance is required. Inductor (L1) (1) Low DCR for good efficiency. (2) Inductance saturate current must higher than the output current. 9. Evaluation Board BOM List: Item Value C1, C2 10µF C3 100pF L1 4.7µH R1 680K 0603 1% R2 150K 0603 1% IC1 PCB Type X5R/X7R, Ceramic/0603 COH/CH, Ceramic/0402 Rating 6.3V Description Vender and Part No. Input coupling CAP, TAIYO YUDEN Output CAP JMK107 BJ106KA-T 6.3V Feed forward CAP 1.2A Inductor TAIYO YUDEN UMK105CH101JV-F TAIYO YUDEN NR3015T 4R7M Voltage set RES PAM2305D PAM2305(D)DFN EB26AA This application note contains new product information. Diodes, Inc. reserves the right to modify the product specification without notice. No liability isassumed as a result of the use of this product. No rights under any patent accompany the sale of the product. PAM2305D EVB User Guide 10. PCB Layout Example Top Layer Bottom Layer This application note contains new product information. Diodes, Inc. reserves the right to modify the product specification without notice. No liability isassumed as a result of the use of this product. No rights under any patent accompany the sale of the product.