Texas Instruments TPS54160EVM-230 User manual

User's GuideSLVU270 – September 2008
TPS54160EVM-230
Contents1 Introduction ................................................................................................................... 21.1 Background .......................................................................................................... 22 Connector Description....................................................................................................... 22.1 Input/Output Connector Descriptions............................................................................. 23 Performance Specifications ................................................................................................ 33.1 Top Converter Specification ....................................................................................... 33.2 Bottom Converter Specification ................................................................................... 44 Test Results .................................................................................................................. 65 Board Layout ................................................................................................................ 115.1 Layout ............................................................................................................... 116 Schematic and Bill of Materials ........................................................................................... 176.1 Schematic .......................................................................................................... 176.2 Bill of Materials .................................................................................................... 18
List of Figures
1 Synchronization to an External Clock .................................................................................... 52 Top Converter Efficiency .................................................................................................... 63 Bottom Converter Efficiency ............................................................................................... 64 Top Converter Transient Response, 0.5A to 1.5A step, Vin=42V ..................................................... 65 Bottom Converter Transient Response, 0.5A to 1.5A step, Vin=48V ................................................. 76 Top Converter Output Voltage Ripple, Vin=42V, Iout=1.5A ............................................................ 77 Bottom Converter Output Voltage Ripple, Vin=60.0V, Iout=1.5A ..................................................... 78 Top Converter Input Voltage Ripple, Vin=42.0V, Iout=1.5A ........................................................... 89 Bottom Converter Input Voltage Ripple, Vin=48.0V, Iout=1.5A ........................................................ 810 Top Converter Start-up relative to Vin, Vin=42V, Iout=1.5A ........................................................... 811 Top Converter UVLO relative to Vin, Iout=1.5A ......................................................................... 912 Bottom Converter Start-up relative to Vin, Vin=60.0V, Iout=1.5A ..................................................... 913 Bottom Converter Start-up relative to EN, Vin=60.0V, Iout=1.5A ..................................................... 914 Bottom Converter Loop Response, Vin=36V, Iout=1.0A .............................................................. 1015 Top Converter Loop Response, Vin=42V, Iout=1.0A .................................................................. 1016 Assembly Layer............................................................................................................. 1217 Top Layer Routing ......................................................................................................... 1318 Layer 2 Routing ............................................................................................................. 1419 Layer 3 Routing ............................................................................................................. 1520 Bottom Layer Routing ...................................................................................................... 1621 TPS54160EVM-230 Schematic .......................................................................................... 17
List of Tables
1 Top Converter Specifications............................................................................................... 42 Bottom Converter Specifications ........................................................................................... 43 TPS54160EVM-230 Bill of Materials – Top Converter ................................................................ 184 TPS54160EVM-230 Bill of Materials – Bottom Converter ............................................................ 18
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1 Introduction
1.1 Background
2 Connector Description
2.1 Input/Output Connector Descriptions
2.1.1 J1 – VIN Top Converter
2.1.2 J2 – GND Top Converter
2.1.3 J3 – VOUT Top Converter
2.1.4 J4 – VOUT Top Converter
2.1.5 J5 – VIN Bottom Converter
Introduction www.ti.com
The TPS54160EVM-230 evaluation module (EVM) helps designers evaluate the operation andperformance of the TPS54160 DC/DC converter. This converter is a wide input voltage (3.5 - 60V),2.5MHz, non-synchronous, externally compensated, step down converter capable of 1.5A of outputcurrent.
The TPS54160EVM-230 provides two independent DC/DC converters based on the TPS54160. Theconverter at the top of the board (top converter) is designed to operate from a nominal 42VDC ±25% inputvoltage source. This input voltage range is typical for input supplies derived from rectified 24VAC sources.The top converter provides a 5.0V output and up to 1.5A of output current. The top converter highlights asmall solution size by using 0402 components with the minimum number of parts needed to provide a fullyfunctional DC/DC converter complete with a programmed enable/disable voltage and soft start features.
The converter at the bottom of the board (bottom converter) is designed to operate from 6.0V to 60V, themaximum recommended input voltage the TPS54160. The bottom converter provides a 3.3V output withup to 1.5A of output current. The bottom converter has additional component footprints that can be usedby the designer to implement a variety of TPS54160 solutions.
This chapter describes the jumpers and connectors on the EVM as well as how to properly connect, setup,and use the TPS54160EVM-230.
This is the positive input supply voltage to the top converter. The leads to the input supply should betwisted and kept as short as possible to minimize EMI transmission. Additional bulk capacitance should beadded between J1 and J2 if the supply leads are greater than six inches. An additional 47 µF or greatercapacitor improves the transient response of the TPS54160 and helps to reduce ringing on the input whenlong supply wires are used.
This is the return connection for the input power supply of the top converter.
This is the positive connection from the output of the top converter. Connect this pin to the positive input ofthe load.
This is the return connection for the output of the top converter.
This is the positive input supply voltage to the bottom converter. The leads to the input supply should betwisted and kept as short as possible to minimize EMI transmission. Additional bulk capacitance should beadded between J5 and J6 if the supply leads are greater than six inches. An additional 47 µF or greatercapacitor improves the transient response of the TPS54160 and helps to reduce ringing on the input whenlong supply wires are used.
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2.1.6 J6 – GND Bottom Converter
2.1.7 J7 – ENABLE Bottom Converter
2.1.8 J8 – TRACK Bottom Converter
2.1.9 J9 – CLK Bottom Converter
2.1.10 J10 – VOUT Bottom Converter
2.1.11 J11 – GND
2.1.12 J12 – PG Top Converter
2.1.13 J13 – PG Bottom Converter
3 Performance Specifications
3.1 Top Converter Specification
www.ti.com Performance Specifications
This is the return connection for the input power supply of the bottom converter.
Pin 1 of this connector is tied to the EN pin of the bottom converter. Pin 2 of this connector is tied to theground plane of the bottom converter. Shorting pin 1 to 2 will disable the converter. Leaving pin 1 and 2open enables the bottom converter.
Pin 1 of this connector is tied to the SS pin of the bottom converter. Pin 2 of this connector is tied to theground plane of the bottom converter. Shorting pin 1 to 2 will disable the converter. Leaving pin 1 and 2open enables the bottom converter.
Pin 1 of this connector is tied to the RT/CLK pin of the bottom converter. Pin 2 of this connector is tied tothe ground plane of the bottom converter.
This is the positive connection from the output of the bottom converter. Connect this pin to the positiveinput of the load.
This is the return connection for the output of the bottom converter.
Pin 1 of this connector is tied to the PWRGD output pin of the top converter. Pin 2 of this connector is tiedto the ground plane of the top converter. R4 is pull up resistor for the PG pin and is connected to theoutput voltage. The maximum voltage of the PWRGD pin is 6V. If the output voltage of the converter is setto any value higher than 6.0V, then R4 must be removed from the board to avoid damaging theTPS54160.
Pin 1 of this connector is tied to the PWRGD pin of the bottom converter. Pin 2 of this connector is tied tothe ground plane of the bottom converter. R12 is pull up resistor for the PG pin and is connected to theoutput voltage. The maximum voltage of the PWRGD pin is 6V. If the output voltage of the converter is setto any value higher than 6.0V, then R12 must be removed from the board to avoid damaging theTPS54160.
Table 1 provides a summary of the top converters specifications. The top converter is designed and testedfor VIN = 31.5V to 52.5V. Operation at other input voltages is possible but some performancespecifications will vary compared to those shown in Table 2 . The ambient temperature is 25 °C for allmeasurements, unless otherwise noted.
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3.1.1 Modifications of the Top Converter
3.2 Bottom Converter Specification
Performance Specifications www.ti.com
Table 1. Top Converter Specifications
SPECIFICATION TEST CONDITIONS MIN TYP MAX UNIT
VIN input voltage range 31.5 42 52.5 VOutput voltage 5.0 VOutput current range 0 1.5 A1 %/VLoad regulation Vin = 42 V 0.13 %/AVoltage change 225 mVLoad transient response
Recovery time 1.0 msLoop bandwidth 29.8 kHzPhase margin 43 °Output voltage ripple Vin = 42 V, Iout = 1.5 V 10 mVppOperating frequency 750 kHzMaximum efficiency Vin = 42 V, Iout = 800 mA 81.5%Converter enable voltage Vin rising, Io = 1 A 25.8 VConverter disable voltage Vin falling, Io = 1 A 25.5 VOutput rise time 32 ms
The top converter is meant to show a small solution size so most of the parts have been selected for theirsmall size. This makes modifications to the top converter difficult since many components are 0402 size.Additionally, to reduce size, there are no additional connectors or jumpers to connect control signals toexternal circuits. The bottom converter was designed to be more adjustable and accommodate off boardsignals and parts that are easier to solder. The bottom converter should be used to evaluate circuitmodifications.
Table 1 provides a summary of the top converters specifications. The bottom converter is designed andtested for VIN = 6.0V to 60V. Operation at other input voltages is possible, but some performancespecifications will vary compared to those shown in Table 2 . The ambient temperature is 25 °C for allmeasurements, unless otherwise noted.
Table 2. Bottom Converter Specifications
SPECIFICATION TEST CONDITIONS MIN TYP MAX UNIT
VIN input voltage range 6 60 VOutput voltage 3.3 VOutput current range 0 1.5 ALine regulation Iout = 1.5 A, Vin = 6 V to 60 V 0.1 %/VLoad regulation 0.11 %/AVoltage change 120 mVLoad transient response
Recovery time 2.0 msLoop bandwidth 18.5 kHzPhase margin 72 °Output voltage ripple 40 mVppOperating frequency 415 kHzMaximum efficiency Vin = 5 V, Iout = 200 mA 94.60%Output rise time 32 ms
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3.2.1 Modifications of the Bottom Converter
3.2.2 Output Voltage Set Point
Vout
R14 = R15 1
0.8
æ ö
´ -
ç ÷
è ø
(1)
3.2.3 External Clock Synchronization
TPS54160
Rt/Clk
C18
10pF
R11
Rt
R16
49.9 Ω
R17
0 Ω
J9
1
2
TPS54160EVM
3.2.4 Programmable Under Voltage Lock Out and Enable
www.ti.com Performance Specifications
The bottom converter provides several features that allow custom TPS54160 designs to be evaluated.Many of the control signals are routed to external connectors for easy access. Additionally, the board uses0603 or larger components and multiple component footprints to ease soldering and assembly of customdesigns.
To change the output voltage of the EVM, it is necessary to change the value of resistor R14. The value ofR14 can be calculated using Equation 1 . The converter should be re-compensated if the output voltage isaltered from the factory default
The PWRGD pin of the TPS54160 is pulled up to the output voltage by R4 on the top converter and R12on the bottom converter. The absolute maximum voltage rating of the PWRGD pin is 6.0V. If the outputvoltage of either converter is modified to be above 6.0V, then the corresponding pull up resistor should beremoved so that the absolute maximum rating of the IC is not exceeded.
The EVM supports connection of an external oscillator for the TPS54160 to synchronize too. A zero ohmresistor should be installed for R17 and a 10pF capacitor installed for C18. Figure 1 shows theconnections and components to synchronize to an external clock source.
Figure 1. Synchronization to an External Clock
The Under Voltage Lock-out (UVLO) and Enable voltages of the TPS54160 have programmable values asshown in the datasheet. The UVLO and Enable levels are programmed using R8 and R9 on the EVM. Seethe TPS54160 data sheet for how to select the value of these resistors. Capacitor C19 can be installed toadd a delay or noise filtering on the EN pin.
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4 Test Results
0.6
0.65
0.7
0.75
0.8
0.85
0.9
0.95
1
0500 1000 1500
I - Output Current - mA
O
Efficiency - %
42 V
0.5
0.55
0.6
0.65
0.7
0.75
0.8
0.85
0.9
0.95
1
0 200 400 600 800 1000 1200 1400
60 V
48 V
36 V
24 V
12 V
5 V
Efficiency - %
I - Output Current - mA
O
Vout
Load Current
50 mV/div
500 mA/div
Test Results www.ti.com
This chapter provides typical performance waveforms for the TPS54160EVM-279 board.
Figure 2. Top Converter Efficiency
Figure 3. Bottom Converter Efficiency
Figure 4. Top Converter Transient Response, 0.5A to 1.5A step, Vin=42V
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Vout
Load Current
50 mV/div
500 mA/div
Vout
Inductor Ripple Current
10 mV/div
100 mA/div
IL
Vout
20 mV/div
200 mA/div
www.ti.com Test Results
Figure 5. Bottom Converter Transient Response, 0.5A to 1.5A step, Vin=48V
Figure 6. Top Converter Output Voltage Ripple, Vin=42V, Iout=1.5A
Figure 7. Bottom Converter Output Voltage Ripple, Vin=60.0V, Iout=1.5A
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Vin
PH
100 mV/div
20 V/div
Vin
PH
100 mV/div
20 V/div
Vin
Vout
20 V/div
2 V/div
Test Results www.ti.com
Figure 8. Top Converter Input Voltage Ripple, Vin=42.0V, Iout=1.5A
Figure 9. Bottom Converter Input Voltage Ripple, Vin=48.0V, Iout=1.5A
Figure 10. Top Converter Start-up relative to Vin, Vin=42V, Iout=1.5A
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Vin
Vout
20 V/div
2 V/div
Vin
Vout
20 V/div
1 V/div
EN
Vout
2 mV/div
1 V/div
www.ti.com Test Results
Figure 11. Top Converter UVLO relative to Vin, Iout=1.5A
Figure 12. Bottom Converter Start-up relative to Vin, Vin=60.0V, Iout=1.5A
Figure 13. Bottom Converter Start-up relative to EN, Vin=60.0V, Iout=1.5A
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60
-60
100 100 k
f - Frequency - Hz
Gain
180
-180
Phase
60
-60
Gain
180
Phase
-180
Test Results www.ti.com
Figure 14. Bottom Converter Loop Response, Vin=36V, Iout=1.0A
Figure 15. Top Converter Loop Response, Vin=42V, Iout=1.0A
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