/ Vref) 1]. Set R7=R14=1k,Vref=0.8V 2. V OUT2

Transcription

1 REFERENCE DESIGN International Rectifier 233 Kansas Street, El Segundo, CA 9245 USA IRDCiP122-A, 3kHz, Dual 15A, 5.5V IN to 13.2V IN Dual Output Synchronous Buck Converter using ip122 Overview The ip122 is fully optimized solution for medium current synchronous buck applications requiring up to 15A or 3A. In this document, Fig. 1 and 2 are provided to enable engineers to easily evaluate the ip122 in an independent and parallel configuration that is capable of providing up to 15A per phase with double-sided heat sinking. Fig. 4, 5 and 6 and the complete bill of materials in Table 1 are provided as a reference design to enable engineers to very quickly and easily design a dual phase converter. In order to optimize this design to your specific requirements, refer to the ip122 data sheet for guidelines on external component selection and user adjustable limits and specifications. Custom designs may require layout modifications. Demoboard Quick Start Guide Initial Settings: The output1 is set to 1.5V and output2 is set to 2.5V for independent configuration. The output1 is set to 1.5V with R4, R8, R1, R11 and R12 removed for parallel configuration. Output can be adjusted from.8v to 3.3V as follow: 1. V OUT1 : R9=R13= R7 [(V OUT 1 / Vref) 1]. Set R7=R14=1k,Vref=.8V 2. V OUT2 : R1=R11= R8 [(V OUT2 / Vref) 1]. Set R8=R12=1k,Vref=.8V. The switching frequency is set to R3=3.9k for 3kHZ The input voltage range can be increased to allow operation between 5.5V IN and 13.2V IN. For paralleled single output operation see Fig. 6 for configuration table in reference design schematic. Procedure for Connecting and Powering Up Demoboard: 1. Apply input voltage (5.5V-13.2V) across V IN and 2. Apply load across pad and pad and pad and pad for independent configuration. 3. Apply load across pad and pad and short R27 for parallel configuration. 4. Adjust load accordingly. IRDCiP122-A Recommended Operating Conditions (refer to the ip122 datasheet for maximum operating conditions) Input voltage: V Output voltage: Can be set between.8v 3.3V Output current: Up to 15A (see recommended operating area Fig. 1, 2 and 3). The maximum current should be limited to 11.5A if the PCB is the only heat sink. Switching Freq: 2kHz to 4kHz selectable. 7/4/3 IRDCiP122-A

2 IRDCiP122-A R OC-SET (k ) V IN = 12V V OUT1 = V OUT2 = 1.5V f SW = 3kHz L = 1 H T BLK = 125 C Overload Current (A) Fig. 1: Nominal Overcurrent Threshold Setting External Resistor Selection for V IN = 12V 4 Switching Frequency in KHz R T in KOhms 2 Fig. 2 : Per Channel Switching Frequency vs R T

3 IRDCiP122-A 92% V IN = 12V, V OUT1 = 1.5V, V OUT2 = 2.5V 9% 88% 86% 84% Efficiency 82% 8% 78% 76% 74% 72% 2kHZ 3kHZ 4kHZ 7% Output Current(A) Fig. 3 - Typical Efficiency vs. Current Refer to the following application notes for detailed guidelines and suggestions when implementing ipowir Technology products: AN-128: Recommended Design, Integration and Rework Guidelines for International Rectifier s ipowir Technology BGA Packages This paper discusses the assembly considerations that need to be taken when mounting ipowir BGA s on printed circuit boards. This includes soldering, pick and place, reflow, inspection, cleaning and reworking recommendations. AN-129: Optimizing a PCB Layout for an ipowir Technology Design This paper describes how to optimize the PCB layout design for both thermal and electrical performance. This includes placement, routing, and via interconnect suggestions. AN-13: Applying ipowir Products in Your Thermal Environment This paper explains how to use the Power Loss and SOA curves in the data sheet to validate if the operating conditions and thermal environment are within the Safe Operating Area of the ipowir product. AN-147: Graphical solution to two branch heatsinking Safe Operating Area This paper is a suppliment to AN-13 and explains how to use the double side Power Loss and SOA curves in the data sheet to validate if the operating conditions and thermal environment are within the Safe Operating Area of the ipowir product. 3

4 IRDCiP122-A SS1 VSW1 FB1 CC1 VP-REF TP1 TP2 C1 C2 C3 C4 16V 16V 16V 16V Output Configuration Designator Independent mode(dual output) 2 phase mode(single output) R15, R19 Short 5mOHM R16 R17 R8 R1 R1 1K R2 1K C8.1uF C7.1uF JP3 R3 3.9K TP6 SYNC HICCUP PGOOD SS1 SS2 RT SYNC HICCUP PGOOD SS2 RT SYNC ip122 OC1 FB1S VREF OC2 VSW2 FB2 CC2 FB2S VSW1 FB1 CC1 FB1S VP-REF VREF.8V VSW2 FB2 CC2 FB2S TP8 VSW1 L1 R15 1uH R9 ** 887 1% 5mOHM (short for independent output configuration) C12 C13 47uF 47uF 6.3V 6.3V C14.1uF C9.18uF R5 2.49K ** R7 1K 1% R % R14 1K 1% R4 R16 C1 1pF TP1 VSW2 L2 1uH R17 R1 2.15k 1% R19 5mOHM (short for independent output configuration) C15 C16 47uF 47uF 6.3V 6.3V C17.1uF C11.12uF R6 3.32K R8 1k 1% R K 1% **For independent mode, output voltages are set by using the following equations: R12 1K 1% For : R9 = R7[(/VREF) - 1]. For : R1 = R8[(/VREF) - 1]. Set R7 (or R8) to 1K, VREF to.8v, and VOUT to desired output, then solve for R9 (or R1 respectively). For parallel (single output) mode, check table on the left. TP11 TP12 TP13 TP JP1 HICCUP OC1 ROC1 51.1K 1% OC2 ROC2 51.1K 1% 2 1 JP1-1 JP3-1 SHUNT SHUNT TP3 TP28 TP4 TP29 CON4 S S VSW1S VSW2S INPUT/OUTPUT Compensation Configuration Designator Type II Configuration Type III Configuration R23, R24, R25, R26 C18, C19 C2, C21 C9, C11 R5, R6 R4 R11 R12 R22 R27 C22 C23 16V 16V C18 C26 1pF C2 C27 1pF VSW1S (1.5V) TP15 R23 R24 C19 C24 TP16 Type III Compensation R27 VSW2S (2.5V) C25 TP17 R25 C21 R26 TP18 FB1S R22 : Not TP2 TP Fig. 4 - Reference Design Schematic

5 IRDCiP122-A Fig. 5 - Component Placement (Top View) SideLayer Fig. 6 - Component Placement (Bottom View) 5

6 IRDCiP122-A IRDCiP122-A (Dual, Independent output configurations(channel1 1.5V output, Channel2 2.5V output) QTY REF DESIGNATOR DESCRIPTION SIZE MFR PART NUMBER 6 C1, C2, C3, C4, C22, C23 Capacitor, ceramic, 33µF, 16V, X5R, 2% 1812 TDK C4532X5R1C336MT 4 C7, C8, C14, C17 Capacitor, ceramic,.1µf, 5V, X7R, 1% 63 TDK C168X7R1H14K 1 C11 Capacitor, ceramic,.12uf, 5V, X7R, 1% 63 Phycomp 632R123K8B2 4 C12, C13, C15, C16 Capacitor, poscap, 47µF, 6.3V, electrolytic 2% 7343 Sanyo 6TPB47M 3 C1, C26, C27 Capacitor, ceramic, 1pF, 5V, NPO, 5% 63 Phycomp 63CG11J9B2 1 C9 Capacitor, ceramic,.18uf, 25V, X7R, 1% 63 Phycomp 632R183K8B2 2 L1, L2 Inductor, 1µH, 19A, 2% 13.mm X 12.9mm Panasonic ETQP1H1RBFA 2 R13, R9 Resistor, thick film, 887Ω, 1/1W, 1% 63 KOA RK73H1J887F 2 R1, R11 Resistor, thick film, 2.15kΩ, 1/1W, 1% 63 KOA RK73H1J2151F 4 R7, R8, R12, R14 Resistor, thick film, 1.kΩ, 1/1W, 1% 63 KOA RK73H1J11F 2 ROC1,ROC2 Resistor, thick film, 51.1kΩ, 1/1W, 1% 63 KOA RK73H1J5112F 2 R15, R19 Resistor, manganin-foil, Ω, 2W 2716 Isotek Corp SMT-R 1 R4 Resistor, thick film, Ω, 1/1W, 5% 63 ROHM MCR3EZHJ 14 C18, C19, C2, C21, C24, C25, R16, R17, R22, R23, Not installed R24, R25, R26, R27 2 R1, R2 Resistor, thick film, 1kΩ, 1/1W, 1% 63 KOA RK73H1J13F 1 R5 Resistor, thick film, 2.49kΩ, 1/1W, 1% 63 KOA RK73H1J2491F 1 R6 Resistor, thick film, 3.32kΩ, 1/1W, 1% 63 KOA RK73H1JLTD3321F 1 R3 Resistor, thick film, 3.9kΩ, 1/1W, 1% 63 KOA RK73H1J392F 1 U1 BGA Power Block 9.25mm X 15.5mm IR ip122 IRDCiP122-A (Single, paralleled output configuration(for 1.5V output) QTY REF DESIGNATOR DESCRIPTION SIZE MFR PART NUMBER 6 C1, C2, C3, C4, C22, C23 Capacitor, ceramic, 33µF, 16V, X5R, 2% 1812 TDK C4532X5R1C336MT 4 C7, C8, C14, C17 Capacitor, ceramic,.1µf, 5V, X7R, 1% 63 TDK C168X7R1H14K 1 C11 Capacitor, ceramic,.12uf, 5V, X7R, 1% 63 Phycomp 632R123K8B2 4 C12, C13, C15, C16 Capacitor, poscap, 47µF, 6.3V, electrolytic 2% 7343 Sanyo 6TPB47M 3 C1, C26, C27 Capacitor, ceramic, 1pF, 5V, NPO, 5% 63 Phycomp 63CG11J9B2 1 C9 Capacitor, ceramic,.18uf, 25V, X7R, 1% 63 Phycomp 632R183K8B2 2 L1, L2 Inductor, 1µH, 19A, 2% 13.mm X 12.9mm Panasonic ETQP1H1RBFA 2 R13, R9 Resistor, thick film, 887Ω, 1/1W, 1% 63 KOA RK73H1J887F 2 R7, R14 Resistor, thick film, 1.kΩ, 1/1W, 1% 63 KOA RK73H1J11F 2 ROC1,ROC2 Resistor, thick film, 51.1kΩ, 1/1W, 1% 63 KOA RK73H1J5112F 2 R15, R19 Resistor, alloy metal, 5mΩ, 1W, 1% 2512 Panasonic ERJM1WSF5MU 1 R27 Resistor, manganin-foil, Ω, 2W 2716 Isotek Corp SMT-R 3 R16, R17, R22 Resistor, thick film, Ω, 1/16W 63 ROHM MCR3EZHJ 15 C18, C19, C2, C21, C24, C25, R1, R11, R12, R4, Not installed R8, R23, R24, R25, R26 2 R1, R2 Resistor, thick film, 1kΩ, 1/1W, 1% 63 KOA RK73H1J13F 1 R5 Resistor, thick film, 2.49kΩ, 1/1W, 1% 63 KOA RK73H1J2491F 1 R6 Resistor, thick film, 3.32kΩ, 1/1W, 1% 63 KOA RK73H1JLTD3321F 1 R3 Resistor, thick film, 3.9kΩ, 1/1W, 1% 63 KOA RK73H1J392F 1 U1 BGA Power Block 9.25mm X 15.5mm IR ip122 Table 1 - Reference Design Bill of Materials Use of this design for any application should be fully verified by the customer. International Rectifier cannot guarantee suitability for your applications, and is not liable for any result of usage for such applications including, without limitation, personal or property damage or violation of third party intellectual property rights. 6 IR WORLD HEADQUARTERS: 233 Kansas St., El Segundo, California 9245, USA Tel: Technical Assistance Center (TAC) Fax :