LM2653-ADJEVAL

www.ti.com Table of Contents User’s Guide LM2653 Step-Down Converter Evaluation Module User's Guide Table of Contents 1 Introduction.............................................................................................................................................................................2 2 Evaluation Board Design....................................................................................................................................................... 2 3 Typical PC Board Layout: (2X Size)...................................................................................................................................... 3 4 References.............................................................................................................................................................................. 5 5 Revision History......................................................................................................................................................................5 Trademarks All trademarks are the property of their respective owners. SNVA012C – MAY 1999 – REVISED DECEMBER 2021 Submit Document Feedback LM2653 Step-Down Converter Evaluation Module User's Guide Copyright © 2021 Texas Instruments Incorporated 1 Introduction www.ti.com 1 Introduction The LM2653 switching regulator provides high efficiency power conversion over a 100:1 load range (1.5A to 15 mA). This feature makes the LM2653 an ideal fit in battery-powered applications. Synchronous rectification and 75 mΩ internal switches provide up to 97% efficiency. At light loads, the LM2653 enters a low power hysteretic or “sleep” mode to keep the efficiency high. In many applications, the efficiency still exceeds 80% at 15 mA load. A shutdown pin is available to disable the LM2653 and reduce the supply current to 7 µA. The IC contains patented current sensing circuitry for current mode control. This feature eliminates the external current sensing required by other current-mode DC-DC converters. The IC has a 300kHz fixed frequency internal oscillator. The high oscillator frequency allows the use of extremely small, low profile components. The evaluation board can be obtained by ordering part number LM2653EVAL from your local Texas Instruments sales office, or TI's website at http://www.ti.com. 2 Evaluation Board Design The evaluation board is designed to supply 2.5 V at up to 1.5A. The input voltage range is 4 V to 14 V. Components were selected based on the design procedure in the LM2653 1.5A High Efficiency Synchronous Switching Regulator Data Sheet (SNVS050). The feedback resistors can be adjusted to achieve a different output voltage: VOUT = 1.238 V x [1+ (R1/R2)] (1) Choose 1% resistors between 10 kΩ to 100 kΩ for R1 and R2. PCB layout is critical to reduce noises and ensure specified performance. For layout guidelines, see the LM2653 1.5A High Efficiency Synchronous Switching Regulator Data Sheet (SNVS050). The artwork for the evaluation board is shown at the end of this application report. The schematic for the evaluation board is shown in Figure 2-1, and the parts list is given in Table 2-1. When the undervoltage protection occurs, the output voltage can be pulled below ground as the inductor current is reversed through the synchronous FET. For applications that need to be protected from a negative voltage, a clamping diode D2 is recommended. The PGOOD flag goes low whenever the overvoltage or undervoltage latch protection is enabled. The overvoltage protection will be enabled immediately when the output voltage exceeds 110% of its nominal. While the undervoltage latch protection will wait for a period of time set by the LDELAY capacitor. If the output voltage is still below 80% of its nominal after this waiting period, the latch protection will be enabled. Figure 2-1. LM2653 EVAL Schematic Table 2-1. Parts List (Bill Of Materials) Designation L1 2 Description 22 µH, Coilcraft DO3316P-223 LM2653 Step-Down Converter Evaluation Module User's Guide Copyright © 2021 Texas Instruments Incorporated SNVA012C – MAY 1999 – REVISED DECEMBER 2021 Submit Document Feedback www.ti.com Typical PC Board Layout: (2X Size) Table 2-1. Parts List (Bill Of Materials) (continued) Designation Description CIN (input capacitor) 100 µF, 16 V, Sprague 594D107X0016D2T CIN2 (input capacitor) 0.1 µF ceramic capacitor CB (bootstrap capacitor) 0.1 µF ceramic capacitor CSS (softstart capacitor) 4.7 nF ceramic capacitor COUT (output capacitor) 120 µF, 6.3 V, Sprague 594D127X06R3C2T CC1 (compensation) 2.2 nF ceramic capacitor CC2 (compensation) 100 pF ceramic capacitor RC (compensation) 30 kΩ, 5% resistor D1 1A Schottky diode, Motorola MBRA130LT3 R1 20.0k, 1% resistor R2 19.6k, 1% resistor CDELAY 100 nF ceramic capacitor RP 50K, 5% resistor D2 Open 3 Typical PC Board Layout: (2X Size) Figure 3-1. Component Placement Guide SNVA012C – MAY 1999 – REVISED DECEMBER 2021 Submit Document Feedback LM2653 Step-Down Converter Evaluation Module User's Guide Copyright © 2021 Texas Instruments Incorporated 3 Typical PC Board Layout: (2X Size) www.ti.com Figure 3-2. Component Side PC Board Layout Figure 3-3. Solder Side PC Board Layout 4 LM2653 Step-Down Converter Evaluation Module User's Guide Copyright © 2021 Texas Instruments Incorporated SNVA012C – MAY 1999 – REVISED DECEMBER 2021 Submit Document Feedback www.ti.com References 4 References LM2653 1.5A High Efficiency Synchronous Switching Regulator Data Sheet (SNVS050) 5 Revision History NOTE: Page numbers for previous revisions may differ from page numbers in the current version. Changes from Revision B (April 2013) to Revision C (December 2021) Page • Updated the numbering format for tables, figures, and cross-references throughout the document. ................2 • Updated the user's guide title............................................................................................................................. 2 SNVA012C – MAY 1999 – REVISED DECEMBER 2021 Submit Document Feedback LM2653 Step-Down Converter Evaluation Module User's Guide Copyright © 2021 Texas Instruments Incorporated 5 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. 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