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User’s Guide
1998 Mixed-Signal Linear Products
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Printed in U.S.A. SLVU001A 07/98
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SLVP089 Synchronous Buck Converter Evaluation Module User’s Guide Literature Number: SLVU001A July 1998 Printed on Recycled Paper
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IMPORTANT NOTICE Texas Instruments and its subsidiaries (TI) reserve the right to make changes to their products or to discontinue any product or service without notice, and advise customers to obtain the latest version of relevant information to verify, before placing orders, that information being relied on is current and complete. All products are sold subject to the terms and conditions of sale supplied at the time of order acknowledgement, including those pertaining to warranty, patent infr
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Related Documentation From Texas Instruments Preface Read This First About This Manual This user’s guide is a reference manual for the SLVP089 Synchronous Buck Converter Evaluation Module used to evaluate the performance of the TL5001 PWM Controller. This document provides information to assist managers and hardware engineers in application development. How to Use This Manual This manual provides the information and instructions necessary to design, construct, operate, and understand the SLVP0
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If You Need Assistance If You Need Assistance . . . If you want to ... Contact Texas Instruments at . . . Visit TI online World Wide Web: http://www.ti.com Request more information World Wide Web: http://www.ti.com/sc/docs/pic/home.htm about Texas Instruments Call the Product Information Mixed Signal Products Center (PIC) hotline: (972) 644–5580 (MSP) (MSP) Send a fax: (972) 480–7800 Write to: Texas Instruments Incorporated Product Information Center, MS 3123 P.O. Box 660246 Dallas, Texas 75266
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Running Title—Attribute Reference Contents 1 Hardware . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1 1.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2 1.2 Schematic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3 1.
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Running Title—Attribute Reference Figures 1–1 Typical Synchronous Buck Converter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2 1–2 Schematic Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4 1–3 Input/Output Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5 1–4 Board Layout . . . . . . . . . . . . .
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Chapter 1 Hardware The SLVP089 Synchronous Buck Converter Evaluation Module (SLVP089) provides a method for evaluating the performance of the TL5001 pulse-width- modulation (PWM) controller. The device contains all of the circuitry necessary to control a switch-mode power supply in a voltage-mode configuration. This manual explains how to construct basic power conversion circuits including the design of the control chip functions and the basic loop. This chapter in- cludes the following topics
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Introduction 1.1 Introduction Synchronous buck converters provide the smaller size and higher efficiency required by electronic equipment, particularly portable battery-operated equipment. The synchronous buck converter reduces power losses associated with a standard buck converter by substituting a power MOSFET for the commutating diode. This reduces the typical 0.5-V to 1-V diode drop to 0.3 V or less and increases system efficiency by up to 10 percent. Continuous-current mode is desirable and
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Schematic µ µ µ µ Ω Ω Ω Ω µ Ω µ µ µ Ω Ω µ µ Ω Ω Ω µ µ µ Ω Ω Ω µ Hardware 1-3 1.2 Schematic Figure 1–2. Schematic Diagram J1 5.5 V to 12 V 1 V I 2 V I + + 3 C10 C5 C11 GND R5 4 100 F 100 F 0.47 F 10 k GND Q1 IRF7406 PMOS C14 0.1 F L1 H 27 J2 R6 R10 C15 C7 C13 C12 1 15 1 k U2 1.0 F 3.3 V 100 F 10 F 100 F + + 2 TPS2812 3.3 V 3 1 6 RTN 4 R7 CR3 RTN C9 0.22 F BAS16ZX V V 3.3 DD CC 2 CR1 8 REG R8 V CC 121 k R12 10 k 6 30BQ015 2 7 DTC 1IN C6 1OUT U1 Q2 1000 pF TL5001 C2 IRF7201 3 R11 30
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Input/Output Connections 1.3 Input/Output Connections Figure 1–3 shows the input/output connections to the SLVP089. Figure 1–3. Input/Output Connections Power Supply – + C5 Q1 Q2 C11 R5 L1 C10 R7 U2 R13 C6 CR1 J1 R12 C14 J2 1 CR3 R6 1 R10 JMP1 C13 C12 C8 R11 CR2 C15 R4 R3 SLVP089 R9 TEXAS INSTRUMENTS U1 EVAL BOARD R8 C4 TL5001 REV2 C3 C9 +3.3V, 3 AMP R2 C1 SYNC. RECT BUCK R1 C2 – LOAD + Notes: 1) Source power should be able to supply a minimum of 2.5 A at 5.5-V input and/or 1.1-A at 12-V input.
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Board Layout 1.4 Board Layout Figure 1–4 shows the SLVP089 board layout. Figure 1–4. Board Layout C5 Q1 Q2 R5 L1 C11 C10 R7 U2 R13 C6 CR1 J1 R12 C14 J2 1 CR3 1 R6 R10 JMP1 C13 C12 C8 R11CR2 C15 R4 R3 R9 TEXAS INSTRUMENTS U1 SLVP089 C4 R8 EVAL BOARD C3 TL5001 C9 REV2 +3.3V, 3 AMP R2 C1 SYNC. RECT BUCK C2 R1 Hardware 1-5
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Bill of Materials 1.5 Bill of Materials Table 1–1 lists materials required for the SLVP089. Table 1–1.Bill of Materials Qty Reference Part Number Mfr Description 1 C1 ECS-T1CY105R Panasonic Capacitor, Tant, 1 F, 20%, A Case 1 C11 Standard Capacitor, Cer, 0.47 F, 10%, X7R, 1210 1 C13 C3225Y5V1C106Z TDK Capacitor, Cer, 10 F, 10 V, Y5V,3225 1 C14 Standard Capacitor, Cer, 0.1 F, 10%, X7R, 1206 1 C2 Standard Capacitor, Cer, 0.033 F, 10%, X7R, 1206 1 C3 Standard Capacitor, Cer, 0.0022 F, 1
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Test Results 1.6 Test Results Tables 1–2 and 1–3, along with Figures 1–5 through 1–8, show the test results for the SLVP089. Table 1–2.Line/Load Regulation, 3.3-V (Total Variation) Line/Load 0.3 A 0.9 A 1.5 A 3.0 A 5.0 A Load Reg. 5.5 V Vo(V) 3.330 3.329 3.328 3.324 3.320 0.18% 6.0 V Vo(V) 3.330 3.329 3.328 3.324 3.320 0.18% 7.0 V Vo(V) 3.330 3.328 3.328 3.325 3.321 0.15% 8.0 V Vo(V) 3.330 3.329 3.328 3.325 3.321 0.15% 9.0 V Vo(V) 3.331 3.330 3.328 3.325 3.321 0.18% 10 V Vo(V
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Test Results Figure 1–6. Power Switch Turn-On and Delay from Q2 Off V = 12 V CC I = 1.5 A O Q1 DRAIN 5 V/DIV 1 Q2 GATE 5 V/DIV 2 20 ns/Div Figure 1–7. Power Switch Turn-Off and Delay to Q2 On V = 12 V CC I = 1.5 A O Q1 Drain 5 V/Div 1 Q2 Gate 5 V/Div 2 20 ns/Div 1-8
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Test Results Figure 1–8. Inductor and Output Ripple V = 12 V CC Inductor I = 1.5 A O Ripple 1 A/Div 1–DC Output Ripple 20 mV/Div 2–AC 2 µ s/Div Hardware 1-9
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1-10
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Chapter 2 Design Procedure There are many possible ways to proceed when designing power supplies. This chapter shows the procedure used in the design of the SLVP089. The chapter includes the following topics: Topic Page 2.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2 2.2 Operating Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3 2.3 Design Procedures . . . . . . . . . . . . . . . . . . . .
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Introduction 2.1 Introduction The SLVP089 is a dc-dc synchronous buck converter module that provides a 3.3-V output at up to 3 A with an input voltage range of 5.5 V to 12 V. The PWM controller is a TL5001 operating at a nominal frequency of 100 kHz. The TL5001 is configured for a maximum duty cycle of 100 percent and has short- circuit protection built in. The synchronous power stage consists of a PMOS switch and an NMOS synchronous rectifier. 2-2
