PAM2321 EVB User Guide PAM2321 TDFN3x3-10 EV Board User Guide AE Department 1. Revision Information Date 2011/09 Revision V1.0 Description Initial Release Comment 2. PAM2321 General Description The PAM2321 is a 2A step-down converter with a typical input voltage of 3.3V and a fixed output voltage of 1.2V or an adjustable output. The 3MHz switching frequency enables the use of small external components. The ultra-small 3mm x 3mm footprint and high efficiency make the PAM2321 an ideal choice for portable applications. The PAM2321 delivers 2A maximum output current while consuming only 55µA no-load quiescent current. Low RDS(ON) integrated MOSFETs and 100% duty cycle operation make the PAM2321 the ideal choice for high output voltage, high current applications which require a low dropout threshold. The PAM2321 provides excellent transient response and output accuracy across the operating range. The PAM2321 maintains high efficiency throughout the load range. The PAM2321 automatically optimizes efficiency during light load mode (PSM) and maintains constant frequency and low output ripple during PWM mode. Over-temperature and short circuit protection safeguard the PAM2321 and system components from damage. The PAM2321 is available in a Pb-free, ultra-small, low profile, TDFN 3X3-10 and DFN 3X3-6 package. The product is rated over a temperature range of -40°C to +85°C. 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. PAM2321 EVB User Guide 3. Key Features 2A Maximum Output Current 55µA No Load Quiescent Current Tiny 0.47µH Chip Inductor 100% Duty Cycle Low-Dropout Operation Excellent Transient Response Internal Soft Start Input Voltage: 2.7V to 5.5V Over-Temperature and Current Limit Fixed or Adjustable Output Voltage Options: Protection - Fixed Output Voltage: 1.2V <1µA Shutdown Current - Adjustable Output Voltage: 1.0V to 3.3V -40°C to +85°C Temperature Range High Efficiency with 3MHz Switching Pb-Free/Halogen Free Package Frequency RoHS/REACH Compliant 4. EV Board Schematic EN 1 2 3 IC1 EN 1 Vin 2 3 C2 C1 C6 4 FB 5 C3 R1 10 EN PGND PVIN PGND VIN SW AGND SW FB AGND 9 L1 Vout 8 7 C4 C5 6 R2 Vout 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. PAM2321 EVB User Guide 5. EVB PAM2321 EB19AA DFN33-10 Description PAM2321 EB19AA DFN33-10 is an evaluation board for the PAM2321 TDFN3X3-10, a DC/DC converter. The board is targeted to be used in providing a simple and convenient evaluation environment for the PAM2321. Requires parts, power supply connectors etc. on the board, which makes it easy to be evaluated. 6. EV Board View 7. Resistor Slect for Output Voltage Setting VOUT = (1+R1/R2) x VREF Vo 1.2V 1.5V 1.8V 2.5V 3.3V R1 150k 225k 300k 475k 680k (VREF = 0.6V) R2 150k 150k 150k 150k 150k L 0.47µH 0.47µH 0.47µH 1.0µH 1.0µH 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. PAM2321 EVB User Guide 8. External Components Selection Input & Output Capacitors (C2, C6; C4) (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 C2 10µF C6 1µF C4 10µF C3 100pF L1 1µH R1 R2 IC1 680K 150K PCB Type X5R/X7R, Ceramic/0805 X5R/X7R, Ceramic/0603 X5R/X7R, Ceramic/0805 COH/CH, Ceramic/0402 0603 0603 PAM2321 PAM2321 EB19AA DFN33-10 Rating Description 10V Input coupling CAP 25V Input coupling CAP 10V Output CAP 50V Feed forward CAP >3A Inductor 1% 1% TDFN3x3-10 Vender and Part No. TAIYO YUDEN EMK212ABJ106KD-T TAIYO YUDEN TMK107 BJ105KA-T TAIYO YUDEN EMK212ABJ106KD-T TAIYO YUDEN UMK105CH101JV-F 744042001 Wurth Voltage set RES 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. PAM2321 EVB User Guide 10. PCB Layout Guideline The following guidelines should be used to help ensure a proper layout: 1). The input capacitor should be close to IC as close as possible. 2). Must put a small decoupling capacitor between Vin Pin and AGND Pin. 3). Minimize the switching loop area to avoid excessive switching noise. 4). AGND and PGND should connect at input capacitor GND. 5). For the good thermal dissipation, PAM2321 has a heat dissipate pad in the bottom side, it should be soldered to PCB surface. For the copper area can’t be large in the component side, so we can use multiple vias connect to other side of the PCB. 11. PCB Layout Example Top 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. PAM2321 EVB User Guide 11. PCB Layout Example (cont.) 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.