Texas Instruments TPS54373EVM-237 User Manual Download Page 30

Layout

3-2

3.1

Layout

The board layout for the TPS54373EVM-237 is shown in Figure 3–1 through
Figure 3–3. The top-side layer of the TPS54373EVM-237 is laid out in a
manner typical of a user application. The bottom layer of the
TPS54373EVM-237 is designed to accommodate optional alternate output
filter capacitors. The top and bottom layers are 1.5 oz. copper.

The top layer contains the main power traces for V

I

, V

O

, and V

(phase)

. Also on

the top layer are connections for the remaining pins of the TPS54373 and a
large area filled with ground. The bottom layer contains ground and V

O

 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 with
multiple vias placed around the board including ten directly under the
TPS54373 device to provide a thermal path from the PowerPAD

 land to

ground.

The input decoupling capacitors (C9 and C10), bias decoupling capacitor
(C4), and bootstrap capacitor (C3) are all located as close to the IC as
possible. In addition, the compensation components are kept close to the IC.
The compensation circuit ties to the output voltage at the point of regulation,
adjacent to the high frequency bypass output capacitor.

Figure 3–1. Top-Side Layout

Summary of Contents for TPS54373EVM-237

Page 1: ...June 2003 PMP Systems Power User s Guide SLVU088...

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: ...ting any load to the EVM output If there is uncertainty as to the load specification please contact a TI field representative During normal operation some circuit components may have case temperatures...

Page 5: ...Results Chapter 3 Board Layout Chapter 4 Schematic and Bill of MAterials Information About Cautions and Warnings This book may contain cautions and warnings This is an example of a caution statement A...

Page 6: ...Information About Cautions and Warnings vi Trademarks SWIFT is a trademark of Texas Instruments PowerPAD is a trademark of Texas Instruments...

Page 7: ...1 Input Output Connections 2 2 2 2 Efficiency 2 3 2 3 Power Dissipation 2 4 2 4 Output Voltage Regulation 2 5 2 5 Load Transients 2 6 2 6 Loop Characteristics 2 7 2 7 Output Voltage Ripple 2 8 2 8 Inp...

Page 8: ...2 9 2 11 Measured Start Up Waveform TPS54373 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 St...

Page 9: ...port documentation for the TPS54373EVM 237 evaluation module SLVP237 The TPS54373EVM 237 performance specifications are given with the schematic and bill of material for the TPS54373EVM 237 Topic Page...

Page 10: ...f the TPS54373 are incorporated inside the TPS54373 package This eliminates the need for external MOSFETs and their associated drivers The low drain to source on resistance of the MOSFETs gives the TP...

Page 11: ...operating range of the TPS54373 device Table 1 2 TPS54373EVM 237 Performance Specification Summary Specification Test Conditions Min Typ Max Units Input voltage range 3 0 3 3 or 5 0 6 V Output voltage...

Page 12: ...W 0 891 V V O 0 891 V Table 1 3 Output Voltage Programming Output Voltage V R2 Value k 0 9 1000 1 2 28 7 1 5 14 7 1 8 9 76 2 5 5 49 3 3 3 74 The minimum output voltage is limited by the minimum contro...

Page 13: ...primary intended usage for the TPS54373 device family is in applications requiring a precharge condition on the output These types of applications include power supplies for DSPs and microprocessors...

Page 14: ...oes not begin switching If a voltage transient on the precharge voltage source causes the series diodes to conduct current may be sunk through the low side FET in the device possibly damaging the devi...

Page 15: ...the TPS54373EVM 237 and covers efficiency output voltage regulation load transients loop response output ripple input ripple and start up Topic Page 2 1 Input Output Connections 2 2 2 2 Efficiency 2 3...

Page 16: ...or In typical applications it is usually located close to the input voltage source When using the TPS54373EVM 237 with an external power supply as the source for VI an additional bulk capacitor may be...

Page 17: ...emperature of 25 C The efficiency is lower at higher ambient temperatures due to temperature variation in the drain to source resistance of the MOSFETs The efficiency is slightly lower at 700 kHz than...

Page 18: ...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 dissipation is shown for input voltages of 3...

Page 19: ...5 Measurements are given for an ambient temperature of 25 C Figure 2 4 Load Regulation 0 5 0 4 0 3 0 2 0 1 0 0 1 0 2 0 3 0 4 0 5 0 0 5 1 1 5 2 2 5 3 3 5 Output Voltage Change OUTPUT VOLTAGE vs OUTPUT...

Page 20: ...ad transients is shown in Figure 2 6 The current step is from 25 to 75 of maximum rated load Total peak to peak voltage variation is as shown including ripple and noise on the output Figure 2 6 Load T...

Page 21: ...ge Figure 2 7 Measured Loop Response TPS54373 VI 3 V 60 50 40 30 20 10 0 10 20 30 40 50 60 100 1 k 10 k 100 k 1 M 180 150 120 90 60 30 0 30 60 90 120 150 180 Gain Phase Gain dB f Frequency Hz MEASURED...

Page 22: ...oltage ripple is shown in Figure 2 9 The input voltage is 3 3 V for the TPS54373 Output current is the rated full load of 3 A Voltage is measured directly across output capacitors Figure 2 9 Measured...

Page 23: ...Ripple The TPS54373EVM 237 output voltage ripple is shown in Figure 2 10 The input voltage is 3 3 V for the TPS54373 Output current for each device is rated full load of 3 A Figure 2 10 Input Voltage...

Page 24: ...hes 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 st...

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

Page 26: ...rop across the diodes and the final precharge voltage As 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 pr...

Page 27: ...Start Up 2 13 Test Setup and Results Figure 2 15 Measured Start Up Waveform Four Diode Precharge and No Load VI 500 mV div Time Scale 5 ms div VO 500 mV div...

Page 28: ...2 14...

Page 29: ...3 1 Board Layout Board Layout This chapter provides a description of the TPS54373EVM 237 board layout and layer illustrations Topic Page 3 1 Layout 3 2 Chapter 3...

Page 30: ...with 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...

Page 31: ...Layout 3 3 Board Layout Figure 3 2 Bottom Side Layout looking from top side Figure 3 3 Top Side Assembly...

Page 32: ...3 4...

Page 33: ...ematic and Bill of Materials Schematic and Bill of Materials The TPS54373EVM 237 schematic and bill of materials are presented in this chapter Topic Page 4 1 Schematic 4 2 4 2 Bill of Materials 4 3 Ch...

Page 34: ...PwrPad TPS54373PWP U1 J1 2 1 Vin GND C1 C10 10 F TP2 TP3 TP1 R3 6 34 k C6 1500 pF C7 82 pF TP10 C3 0 047 F R6 10 k R5 590 R1 10 k R2 9 76 k C8 820 pF TP8 R7 0 TP4 C15 C16 R8 2 4 L1 1 H C14 3300 pF C2...

Page 35: ...pin 100 mil spacing 36 pin strip 0 100 x 2 Sullins PTC36SAAN 3 Shunt 100 mil black 0 100 3M 929950 00 1 L1 Inductor SMT 1 0 H 8 5 A 10 m 0 270 sq Vishay IHLP 2525CZ 01 1 R1 R6 Resistor chip 10 0 k 1 1...

Page 36: ...4 4...

Reviews: