PAM2312 EVB User Guide PAM2312 EV Board User Guide AE Department 1. Revision Information Date 2010/09 Revision V1.0 Description Initial Release Comment 2. PAM2312 General Description The PAM2312 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 PAM2312 have a power-saving Pulse-skipping Modulation (PSM) mode and reduce the quiescent current under light load operation to save power. The PAM2312 is supported with a range of input voltages from 2.5V to 5V, allowing the use of a single Li+/Li-polymer cell, 3-cell Alkaline/NiMH batteries, USB, and other standard power sources. The output voltage is adjustable from 0.6V to the input voltage, while the suffix part numbers PAM2312-XX indicate pre-set voltage ranges of 3.3V, 1.8V, 1.5V or 1.2V. All versions include internal power switch and synchronous rectifier for minimal external part count and high efficiency. During the 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. 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. PAM2312 EVB User Guide 3. Key Features z z z z z Efficiency up to 96% 40µA (typ) Quiescent Current Internal Synchronous Rectifier 1.5MHz Switching frequency to minimize inductor value Soft Start z z z z z z Under-Voltage Lockout Short Circuit Protection Up to 800mA output current Thermal Shutdown 5-pin Small SOT23-5 Package Pb-Free Package 4. EV Board Schematic Vin 4 IC1 Vin SW EN 1 2 FB 1 EN EN VFB C3 C2 5 R2 2 3 R1 SW GND C1 3 Vo L1 5. EVB PAM2312 EB05AA Description PAM2312 EB05AA is an evaluation board for the PAM2312, a DC/DC converter. The board is targeted to be used in providing a simple and convenient evaluation environment for the PAM2312. Requires parts, power supply jacks 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. PAM2312 EVB User Guide 6. EV Board View Top View EV board operational sequence: a. Connect power supply to VIN and GND. b. Connect load to VO and GND. c. Connect EN up side to enable the chip. 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. PAM2312 EVB User Guide 7. EV Board BOM List Item Value C1 10µF C2 10µF C3 100pF L1 IC1 PCB 4.7µH PAM2312 Type X5R/X7R, Ceramic/0805 X5R/X7R, Ceramic/0805 NPO/COG, 0603 3.7mm*3.0mm SOT-23-5 PAM2312 EB05AA VOUT = (1+R1/R2)×VREF Vo 1.2V 1.5V 1.8V 2.5V 3.3V Rating Description Vender and Part No. 10V Input coupling CAP JMK212BJ106MA 10V Input coupling CAP JMK212BJ106MA 50V Forward CAP UMK105 CG101JV-F 1.2A Inductor Power management IC NR4012T 3R3M PAM2312 (VREF = 0.6V) R1 150k 225k 300k 475k 680k R2 150k 150k 150k 150k 150k 8. External Compnents Selection Input & output Capacitors (C1, C2) (1) For lower output ripple, low ESR is required. (2) Low leakage current needed, 10uF, X5R/X7R ceramic recommend Feed forward capacitor (C3) (1) Lower the output ripple (2) Low leakage current needed, 20-100pF, NPO/COG 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) Inductor rated Current must higher than the output current 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. PAM2312 EVB User Guide 9. 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.