Texas Instruments TPS54973EVM-017 User Manual Download Page 9

1-1

Introduction

 

This chapter contains background information for the TPS54973 as well as
support documentation for the TPS54973EVM-017 evaluation module
(HPA0017). The TPS54973EVM-017 performance specifications are given,
as well as modifications.

Topic

Page

1.1

Background

1-2

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1.2

Performance Specification Summary

1-3

. . . . . . . . . . . . . . . . . . . . . . . . . . . 

1.3

Modifications

1-4

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Chapter 1

Summary of Contents for TPS54973EVM-017

Page 1: ...E September 2003 PMP Systems Power User s Guide SLVU091...

Page 2: ...itute a license from TI to use such products or services or a warranty or endorsement thereof Use of such information may require a license from a third party under the patents or other intellectual p...

Page 3: ...handling or use of the goods Please be aware that the products received may not be regulatory compliant or agency certified FCC UL CE etc Due to the open construction of the product it is the user s r...

Page 4: ...ere is uncertainty as to the load specification please contact a TI field representative During normal operation some circuit components may have case temperatures greater than 55 C The EVM is designe...

Page 5: ...hapter 4 Schematic and Bill of Materials FCC Warning This equipment is intended for use in a laboratory test environment only It gen erates uses and can radiate radio frequency energy and has not been...

Page 6: ...iv...

Page 7: ...erations 1 5 1 3 5 Input Capacitor 1 6 2 Test Setup and Results 2 1 2 1 Input Output Connections 2 2 2 2 Efficiency 2 4 2 3 Power Dissipation 2 5 2 4 Output Voltage Regulation 2 6 2 5 Load Transients...

Page 8: ...eform TPS54973 With No Precharge 2 10 2 12 Measured Start Up Waveform Two Diode Precharge 2 11 2 13 Measured Start Up Waveform Three Diode Precharge 2 11 2 14 Measured Start Up Waveform Four Diode Pre...

Page 9: ...4973 as well as support documentation for the TPS54973EVM 017 evaluation module HPA0017 The TPS54973EVM 017 performance specifications are given as well as modifications Topic Page 1 1 Background 1 2...

Page 10: ...ncorporated inside the TPS54973 package This eliminates the need for external MOSFETs and their associated drivers The low drain to source on resistance of the MOSFETs provides the TPS54973 high effic...

Page 11: ...seful operating range of the TPS54973 device Table 1 2 TPS54973EVM 017 Performance Specification Summary Parameters Test Conditions Min Typ Max Units Input voltage range 3 0 3 3 4 0 V Output voltage s...

Page 12: ...1 R2 10 kW 0 891 V V O 0 891 V Table 1 3 Output Voltage Programming Output Voltage V R2 Value kW 0 9 1000 1 2 28 7 1 5 14 7 1 8 9 76 2 5 5 49 The minimum output voltage is limited by the minimum cont...

Page 13: ...e output for a wide variety of output filter component values it is always a good idea to verify any changes to the output filter or compensation network 1 3 4 Precharge Considerations The primary int...

Page 14: ...e to a level higher than the preset output voltage If this condition occurs during startup the TPS54973 device does not begin switching If a voltage transient on the precharge voltage source causes th...

Page 15: ...3EVM 017 and covers efficiency output voltage regulation load transients loop response output ripple input ripple and startup Topic Page 2 1 Input Output Connections 2 2 2 2 Efficiency 2 4 2 3 Power D...

Page 16: ...probe to monitor the output voltage The TPS54973 is intended to be used as a point of load regulator In typical applications it is usually located close to the input voltage source When using the TPS...

Page 17: ...onnections 2 3 Test Setup and Results Figure 2 1 Connection Diagram Load 0 9A CH1 Oscilloscope 3 4V 8 A Voltmeter 3 4 V 8 A Optional Input Capacitor Optional Precharge Connection Voltmeter POWER SUPPL...

Page 18: ...ature of 25 C The efficiency is lower at higher ambient temperatures due to temperature variation in the drain to source resistance of the MOSFETs Efficiency is slightly lower at 700 kHz than at lower...

Page 19: ...and a 9 A load the junction temperature is approximately 60 C while the case temperature is approximately 55 C The total circuit losses at 25 C are shown in Figure 2 3 Power dissipaton is shown for a...

Page 20: ...s are shown for an ambient temperature of 25 C Figure 2 4 Load Regulation OUTPUT VOLTAGE vs OUTPUT CURRENT IO Output Current A Output Voltage Change V O 0 5 0 4 0 3 0 2 0 1 0 0 1 0 2 0 3 0 4 0 5 0 1 2...

Page 21: ...oad Transient Response TPS54973 VO ac 50 mV div IO 2 A div t Time 200 s div 2 6 Loop Characteristics The TPS54973EVM 017 loop response characteristics are shown in Figure 2 7 and Figure 2 8 Gain and p...

Page 22: ...in Gain dB f Frequency Hz MEASURED LOOP RESPONSE Phase deg 2 7 Output Voltage Ripple The TPS54973EVM 017 output voltage ripple is shown in Figure 2 9 The input voltage is 3 3 V for the TPS54973 Output...

Page 23: ...Ripple The TPS54973EVM 017 output voltage ripple is shown in Figure 2 10 The input voltage is 3 3 V for the TPS54973 Output current for each device is the rated full load of 9 A Figure 2 10 Input Volt...

Page 24: ...up with the slow start ramp rate At this point the voltage on the VSENSE pin matches the internal reference and the output continues to ramp up to the final set point value of 1 8 V at the slow start...

Page 25: ...up and Results Figure 2 12 Measured Start Up Waveform Two Diode Precharge VI 500 mV div t Time 5 ms div VO 500 mV div Figure 2 13 Measured Start Up Waveform Three Diode Precharge VI 500 mV div t Time...

Page 26: ...s in the previous example when the internal reference exceeds the voltage fed back to the VSENSE pin the output begins to ramp up to its final preset value at the slow start rate It is important to no...

Page 27: ...3 1 Board Layout This chapter provides a description of the TPS54973EVM 017 board layout and layer illustrations Topic Page 3 1 Layout 3 2 Chapter 3...

Page 28: ...h ground The bottom layer contains ground and VO copper areas some signal routing and pads for two optional D3 or D4 case size electrolytic capacitors The top and bottom ground traces are connected wi...

Page 29: ...Layout 3 3 Board Layout Figure 3 2 Internal Layer 2 Figure 3 3 Internal Layer 3...

Page 30: ...Layout 3 4 Figure 3 4 Bottom Side Layout Figure 3 5 Top Side Assembly...

Page 31: ...Layout 3 5 Board Layout Figure 3 6 Bottom Layer Assembly...

Page 32: ...4 1 Schematic and Bill of Materials The TPS54973EVM 017 schematic and bill of materials are presented in this chapter Topic Page 4 1 Schematic 4 2 4 2 Bill of Materials 4 3 Chapter 4...

Page 33: ...9 8 7 6 5 19 18 17 16 15 R4 0 047 F TP9 C5 C4 1 F R6 71 5 k 10 k TP4 R3 R1 10 k 4 02 k C6 3300 pF C8 1200 pF R5 383 C7 120 pF R2 9 76 k TP10 R7 0 TP2 VOUT TP5 J1 VOUT GND 2 1 TP1 C14 0 1 F C13 22 F C...

Page 34: ...N 3 Shunt 100 mil black 0 100 3M 929950 00 1 L1 Inductor 0 65 H 12 A 0 340 0 250 Pulse PA0277 1 L2 Open 0 51 0 51 2 R1 R6 Resistor chip 10 0 k 1 16 W 1 603 Std Std 1 R2 Resistor chip 9 76 k 1 16 W 1 6...

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