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SLVP089 Synchronous Buck

Converter Evaluation Module

1998

Mixed-Signal Linear Products

User’s Guide

Содержание SLVP089

Страница 1: ...SLVP089 Synchronous Buck Converter Evaluation Module 1998 Mixed Signal Linear Products User s Guide...

Страница 2: ...Printed in U S A 07 98 SLVU001A...

Страница 3: ...SLVP089 Synchronous Buck Converter Evaluation Module User s Guide Printed on Recycled Paper Literature Number SLVU001A July 1998...

Страница 4: ...ONDUCTOR PRODUCTS MAY INVOLVE POTENTIAL RISKS OF DEATH PERSONAL INJURY OR SEVERE PROPERTY OR ENVIRONMENTAL DAMAGE CRITICAL APPLICATIONS TI SEMICONDUCTOR PRODUCTS ARE NOT DESIGNED AUTHORIZED OR WARRANT...

Страница 5: ...hardware requirements Chapter 2 describes design considerations and procedures and Appendix A contains the data sheet for the TL5001 PWM Controller Related Documentation From Texas Instruments The fol...

Страница 6: ...ite to Texas Instruments Incorporated MSP Marketing Documentation Correction MS 8710 P O Box 660199 Dallas Texas 75266 0199 Notes 1 The literature number for the book is required see the lower right c...

Страница 7: ...oard Layout 1 6 1 5 Bill of Materials 1 7 1 6 Test Results 1 8 2 Design Procedure 2 1 2 1 Introduction 2 2 2 2 Operating Specifications 2 3 2 3 Design Procedures 2 4 2 3 1 Duty Cycle Estimate 2 4 2 3...

Страница 8: ...ower Switch Turn On and Delay from Q2 Off 1 9 1 7 Power Switch Turn Off and Delay to Q2 On 1 9 1 8 Inductor and Output Ripple 1 10 2 1 Power Stage Bode Plot 2 7 2 2 Compensation Network 2 7 2 3 Bode P...

Страница 9: ...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...

Страница 10: ...Figure 1 1 shows a typical synchronous buck converter Figure 1 1 Typical Synchronous Buck Converter Controller FB R1 R2 Q1 Q2 R3 R4 CR1 C2 C1 VO VI L1 Transistor Q1 is the power switch and Q2 is the...

Страница 11: ...NMOS Q2 U2 TPS2812 C14 0 1 F CR3 BAS16ZX C11 0 47 F C5 100 F C10 100 F 2 3 4 1 J1 I V GND 2 3 4 1 J2 5 5 V to 12 V Q1 IRF7406 PMOS C4 0 022 F R3 R4 CR1 30BQ015 R7 C6 1000 pF L1 27 H C12 100 F C7 100...

Страница 12: ...5 R7 R13 C6 C11 C10 L1 J1 J2 R12 CR3 CR2 R11 C14 R6 R10 JMP1 C12 C8 C13 TEXAS INSTRUMENTS C15 R4 R3 C4 C3 R1 R9 R8 C9 C1 SLVP089 EVAL BOARD REV2 R2 C2 U1 LOAD Power Supply CR1 1 1 Notes 1 Source power...

Страница 13: ...s the SLVP089 board layout Figure 1 4 Board Layout C5 Q1 Q2 TL5001 3 3V 3 AMP SYNC RECT BUCK U2 R5 R7 R13 C6 C11 C10 L1 J1 J2 R12 CR3 CR2 R11 C14 R6 R10 JMP1 C12 C8 C13 TEXAS INSTRUMENTS C15 R4 R3 C4...

Страница 14: ...Capacitor Cer 1000 pF 5 NPO 0805 1 C9 Standard Capacitor Cer 0 22 mF 10 X7R 1210 1 CR1 30BQ015 IR Rectifier Schottky 3 A 15 V 2 CR2 CR3 BAS16ZXCT Zetex Diode Signal SOT 23 2 J1 J2 Standard Connector...

Страница 15: ...8 3 325 3 321 0 18 11 V Vo V 3 331 3 330 3 328 3 325 3 321 0 18 12 V Vo V 3 331 3 330 3 329 3 325 3 321 0 18 Line Reg 0 03 0 06 0 03 0 03 0 03 Note The calculation for load regulation only accounts fo...

Страница 16: ...6 Power Switch Turn On and Delay from Q2 Off VCC 12 V IO 1 5 A Q1 DRAIN 5 V DIV Q2 GATE 5 V DIV 20 ns Div 1 2 Figure 1 7 Power Switch Turn Off and Delay to Q2 On VCC 12 V IO 1 5 A Q1 Drain 5 V Div Q2...

Страница 17: ...Test Results 1 9 Hardware Figure 1 8 Inductor and Output Ripple VCC 12 V IO 1 5 A Inductor Ripple 1 A Div Output Ripple 20 mV Div 2 s Div 1 DC 2 AC...

Страница 18: ...1 10...

Страница 19: ...ny 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...

Страница 20: ...p 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 ha...

Страница 21: ...ts the operating specifications for the SLVP089 Table 2 1 Operating Specifications Specification Min Typ Max Units Input Voltage Range 5 5 12 V Output Voltage Range 3 10 3 30 3 50 V Output Current Ran...

Страница 22: ...uous mode operation down to 15 percent of the rated out put load DIO 2 0 15 IO 2 0 15 3 0 9 A The inductor value is L VI VSAT VO D t DIO 12 0 15 3 3 0 29 10 10 6 0 9 27 6 mH Assuming that all of the i...

Страница 23: ...tifier serves as a backup device for the synchronous switch and conducts during the time interval when both devices are off The 30BQ015 is a 3 A 15 V rectifier in an SMC power surface mount package If...

Страница 24: ...ould have a time constant that is greater than the soft start time constant This time constant is chosen to be 75 ms C mF 12 46 tSCP 12 46 0 075 s 0 93 mF 2 3 7 Loop Compensation Loop compensation is...

Страница 25: ...on is enough to calculate the required compensation values Figure 2 1 shows the power stage gain and phase plots Figure 2 1 Power Stage Bode Plot 10 0 20 30 Gain Solid 20 40 Frequency FREQUENCY RESPON...

Страница 26: ...ain of at least 42 dB With a desired crossover fre quency of 20 kHz and a desired slope of 20 dB per decade choose an integra tor frequency of 2 kHz This gives a gain of 46 dB at 10 Hz which is suffic...

Страница 27: ...0 30 10 10 30 50 90 Phase Degrees Dashed 10 102 103 104 105 5 70 Note from the output response shown in Figure 2 4 that the minimum phase margin is 40 degrees and the bandwidth is 18 kHz under nominal...

Страница 28: ...2 10...