LM2642REVD EVAL

www.ti.com Table of Contents User’s Guide LM2642 Evaluation Board Module User's Guide Table of Contents 1 Introduction.............................................................................................................................................................................2 2 Optional Components............................................................................................................................................................ 3 3 Powering Up............................................................................................................................................................................4 4 Revision History......................................................................................................................................................................7 Trademarks All trademarks are the property of their respective owners. SNVA055I – JULY 2002 – REVISED JANUARY 2022 Submit Document Feedback LM2642 Evaluation Board Module User's Guide Copyright © 2022 Texas Instruments Incorporated 1 Introduction www.ti.com 1 Introduction The LM2642 evaluation board has been developed to aid in the design and evaluation of DC/DC converters based on the LM2642 controller IC. As shown in Figure 3-1, the evaluation board is configured to provide two outputs of 2.5 V/2 A and 1.8 V/2 A from an input range of 4.5 V to 20 V. The corresponding bill of materials is given in Table 3-1. Figure 3-2 and Figure 3-3 show the evaluation board layout. 2 LM2642 Evaluation Board Module User's Guide SNVA055I – JULY 2002 – REVISED JANUARY 2022 Submit Document Feedback Copyright © 2022 Texas Instruments Incorporated www.ti.com Optional Components 2 Optional Components The evaluation board provides several optional component pads for flexibility in changing components. For more information regarding device operation and component selection, see the LM26420/LM26420Q Dual 2.0A, High Frequency Synchronous Step-Down DC-DC Regulator Data Sheet. In switching power supplies, the rapid increase of drain current in the top FET coupled with parasitic inductance generates unwanted LΔi/Δt noise spikes at the source node of the FET (SWx node) and VIN node. The resistor in series with the SWx pin (R6, R11) slows down the gate drive (HDRVx), thus slowing the rise and fall time of the top FET, yielding a longer drain current transition time and reducing switch node ringing. Top FET switching losses will increase with higher resistance values. Small resistors (1 Ω–5 Ω) can also be placed in series with the CBOOTx pin (R7, R12). A CBOOT resistor will slow the rise time of the FET to reduce switch node ringing. To maintain stable regulation, the FBx pins should remain free of noise. The LM2642 evaluation board has components C15 and C22 installed to suppress noise that may be picked up by the FBx traces. Notice that both of these capacitors are placed physically close to the FBx nodes. Pads C17 and C23 are provided for additional output capacitors. SNVA055I – JULY 2002 – REVISED JANUARY 2022 Submit Document Feedback LM2642 Evaluation Board Module User's Guide Copyright © 2022 Texas Instruments Incorporated 3 Powering Up www.ti.com 3 Powering Up Before powering up the LM2642 evaluation board, all external connections should be verified. The power supply input must be turned off and connected with proper polarity to the VIN post, also marked as P1. The channel 1 and channel 2 loads should be connected at the VOUT posts, marked as P2 and P3. Any type of load is acceptable up to 2 A. The load can be on or off at start-up. Output voltage can be monitored with a DVM or oscilloscope by connecting probes to the VOUT posts, P2 and P3. The GND posts are provided primarily for scope probe ground connections. The PGOOD signal can be monitored with a scope probe or DVM at the PGOOD test pin. Once all connections have been verified, input power can be applied. The input voltage must be set between 4.5 V and 20 V. The enable switches for each channel, ON1 and ON2, can be used to turn on the evaluation board once the input power is on. Each channel can be enabled or disabled independently. The switches can also be left on for enabling the evaluation board directly from the power supply input. VIN + 4.5V-20V 10 nF C11 GND 22 C1 1 PF VIN ILIM1 IC1 LM 2642 KS1 RSNS1 R5 2 13k7 1 28 C12 10 PF Q1A 6 UV_ DELAY HDRV1 C2 47 nF SW1 VLIN5 CBOOT1 R1 220k PGOOD1 5 9 LDRV1 PGOOD1 PGND ON/SS1 FB1 C3 10 nF S1 FB2 10 C4 10 nF S2 VDD 19 R4 4R7 C9 4.7PF C10 1 PF ILIM2 24 7 VLIN5 220 pF 3 C5 C6 6.8 nF R2 C8 20k 470pF 12 C7 6.8 nF R3 20k 8 26 27 25 23 C14 0.1 PF KS2 VDD1 RSNS2 VDD 2 6 PH VDD 4R7 C16 150 PF D1A BAW56 HDRV2 COMP1 SW2 COMP2 CBOOT2 LDRV2 C15 0.1 uF R8 20k4 R9 20k GND 11 14 10 PF R10 13 VIN 13k7 + C13 33 PF 15 C19 10 PF 17 16 R11 C21 18 0.1 PF 4R7 R12 0 SGND C17 * 4 Q2A VLIN5 + D2 MBRS140T3 Q1B Si 9936DY 21 Vo1 2.5V/2A Si9936DY L1 R6 R7 0 C18 ON/SS2 + C20 33 PF 20 Si 9936DY Vo2 1.8V/2A L2 4.3 uH VDD C24 150 PF D1B BAW56 + D3 MBRS140T3 Q2B Si9936DY C23 * C22 0.1 PF * Not Installed R13 9k09 R14 20k GND Figure 3-1. Complete Evaluation Board Schematic Table 3-1. Bill of Materials Part # 4 Value Supplier C1 Cer Cap 1 F 50 V Y5V 0805 Taiyo Yuden UMK212F105ZG C2 Cer Cap 47 nF 50 V 10% 0805 Vishay VJ0805Y473KXA C3 Cer Cap 10 nF 50 V 10% 0805 Vishay VJ0805Y103KXA LM2642 Evaluation Board Module User's Guide SNVA055I – JULY 2002 – REVISED JANUARY 2022 Submit Document Feedback Copyright © 2022 Texas Instruments Incorporated www.ti.com Powering Up Table 3-1. Bill of Materials (continued) Part # Value Supplier C4 Cer Cap 10 nF 50 V 10% 0805 Vishay VJ0805Y103KXA C5 Cer Cap 220 pF 25 V 10% 0805 Vishay VJ0805Y221KXA C6 Cer Cap 6.8 nF 50 V 10% 0805 Vishay VJ0805Y682KXA C7 Cer Cap 6.8 nF 50 V 10% 0805 Vishay VJ0805Y682KXA C8 Cer Cap 470 pF 25 V 10% 0805 Vishay VJ0805Y471KXA C9 Cer Cap 4.7 µF 10 V X7R 1206 Taiyo Yuden LMK316BJ475ML C10 Cer Cap 1 µF 10 V X7R 0805 Taiyo Yuden LMK212BJ105ZG C11 Cer Cap 10 nF 50 V 10% 0805 Vishay VJ0805Y103KXA C12 Cer Cap 10 µF 35 V Y5V 1210 Taiyo Yuden GMK325F106ZH C13 Electro Cap 33 µF 50 V Panasonic EEU-FC1H330 C14 Cer Cap 0.1 µF 50 V 10% 0805 Vishay VJ0805Y104KXA C15 Cer Cap 0.1 µF 50 V 10% 0805 Vishay VJ0805Y104KXA C16 Cap-SP 150 µF 6.3 V 20% Panasonic EEFUEOJ151R C17 Not Installed C18 Cer Cap 10 nF 50 V 10% 0805 Vishay VJ0805Y103KXA C19 Cer Cap 10 µF 35 V Y5V 1210 Taiyo Yuden GMK325F106ZH C20 Electro Cap 33 µF 50 V Panasonic EEU-FC1H330 C21 Cer Cap 0.1 µF 50 V 10% 0805 Vishay VJ0805Y104KXA C22 Cer Cap 0.1 µF 50 V 10% 0805 Vishay VJ0805Y104KXA C23 Not Installed C24 Cap-SP 150 µF 6.3 V 20% D1 Switching Diode-Dual 70 V 200 mA BAW56F Fairchild BAW56F D2 Schottky Diode 40 V 1A On Semiconductor MBRS140T31A D3 Schottky Diode 40 V 1A On Semiconductor MBRS140T31A L1 Inductor 6 µH Sumida CEP125-6R0MC L2 Inductor 4.3 µH Sumida CEP125-4R3MC Q1 Si9936DY Vishay Panasonic EEFUEOJ151R Q2 Si9936DY Vishay R1 Res 220 kΩ 0.1W 5% 0805 Vishay CRCW0805224J R2 Res 20 kΩ 0.1W 5% 0805 Vishay CRCW0805203J R3 Res 20 kΩ 0.1W 5% 0805 Vishay CRCW0805203J R4 Res 4.7 Ω 0.1W 5% 0805 Vishay CRCW08054R7J R5 Res 13.7 kΩ 0.1W 1% 0805 Vishay CRCW08051372F R6 Res 4.7 Ω 0.1W 5% 0805 Vishay CRCW08054R7J R7 Res 0 Ω 0.1W 5% 0805 Vishay CRCW08050RJ R8 Res 20.5 kΩ 0.1W 1% 0805 Vishay CRCW08052052F R9 Res 20 kΩ 0.1W 1% 0805 Vishay CRCW08052002F R10 Res 13.7 kΩ 0.1W 1% 0805 Vishay CRCW08051372F R11 Res 4.7 Ω 0.1W 5% 0805 Vishay CRCW08054R7J R12 Res 0 Ω 0.1W 5% 0805 Vishay CRCW08050RJ R13 Res 9.09 kΩ 0.1W 1% 0805 Vishay CRCW08059092F R14 Res 20 kΩ 0.1W 1% 0805 Vishay CRCW08052002F S1 Switch SPST 0.4VA 28 V AC/DC A12AB NKK A12AB S2 Switch SPST 0.4VA 28 V AC/DC A12AB NKK A12AB SNVA055I – JULY 2002 – REVISED JANUARY 2022 Submit Document Feedback LM2642 Evaluation Board Module User's Guide Copyright © 2022 Texas Instruments Incorporated 5 Powering Up www.ti.com Figure 3-2. Top Layer Figure 3-3. Bottom Layer 6 LM2642 Evaluation Board Module User's Guide SNVA055I – JULY 2002 – REVISED JANUARY 2022 Submit Document Feedback Copyright © 2022 Texas Instruments Incorporated www.ti.com Revision History 4 Revision History NOTE: Page numbers for previous revisions may differ from page numbers in the current version. Changes from Revision H (April 2013) to Revision I (January 2022) Page • Updated the numbering format for tables, figures, and cross-references throughout the document. ................2 • Updated the user's guide title............................................................................................................................. 2 SNVA055I – JULY 2002 – REVISED JANUARY 2022 Submit Document Feedback LM2642 Evaluation Board Module User's Guide Copyright © 2022 Texas Instruments Incorporated 7 IMPORTANT NOTICE AND DISCLAIMER TI PROVIDES TECHNICAL AND RELIABILITY DATA (INCLUDING DATA SHEETS), DESIGN RESOURCES (INCLUDING REFERENCE DESIGNS), APPLICATION OR OTHER DESIGN ADVICE, WEB TOOLS, SAFETY INFORMATION, AND OTHER RESOURCES “AS IS” AND WITH ALL FAULTS, AND DISCLAIMS ALL WARRANTIES, EXPRESS AND IMPLIED, INCLUDING WITHOUT LIMITATION ANY IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT OF THIRD PARTY INTELLECTUAL PROPERTY RIGHTS. These resources are intended for skilled developers designing with TI products. You are solely responsible for (1) selecting the appropriate TI products for your application, (2) designing, validating and testing your application, and (3) ensuring your application meets applicable standards, and any other safety, security, regulatory or other requirements. These resources are subject to change without notice. TI grants you permission to use these resources only for development of an application that uses the TI products described in the resource. Other reproduction and display of these resources is prohibited. No license is granted to any other TI intellectual property right or to any third party intellectual property right. TI disclaims responsibility for, and you will fully indemnify TI and its representatives against, any claims, damages, costs, losses, and liabilities arising out of your use of these resources. TI’s products are provided subject to TI’s Terms of Sale or other applicable terms available either on ti.com or provided in conjunction with such TI products. TI’s provision of these resources does not expand or otherwise alter TI’s applicable warranties or warranty disclaimers for TI products. TI objects to and rejects any additional or different terms you may have proposed. IMPORTANT NOTICE Mailing Address: Texas Instruments, Post Office Box 655303, Dallas, Texas 75265 Copyright © 2022, Texas Instruments Incorporated