Texas Instruments TPS53129EVM-621 User manual

User's Guide
SLVU432–February 2011
TPS53129EVM-621 Evaluation Module
The TPS53129EVM-621 Evaluation Module presents an easy-to-use reference design for a common
dual-output power supply using the TPS53129 controller in cost-sensitive applications.
Contents
1 Introduction .................................................................................................................. 2
2 Electrical Performance Specifications .................................................................................... 2
3 Schematics ................................................................................................................... 3
4 Connector and Test Point Descriptions .................................................................................. 4
5 Test Setup ................................................................................................................... 5
6 Test Procedure .............................................................................................................. 7
7 Performance Data and Typical Characteristic Curves ................................................................. 8
8 EVM Assembly Drawings and Layout .................................................................................. 12
9 Bill of Materials ............................................................................................................. 16
List of Figures
1 TPS53129EVM-621 Schematic........................................................................................... 3
2 Tip and Barrel Measurement for Output Voltage Ripple............................................................... 5
3 TPS53129EVM-621 Recommended Test Setup ....................................................................... 7
4 Efficiency vs Load .......................................................................................................... 9
5 Efficiency vs Load .......................................................................................................... 9
6 Output Voltage vs Load .................................................................................................. 10
7 Output Voltage vs Load .................................................................................................. 10
8 Output Voltage Ripple .................................................................................................... 11
9 Output Voltage Ripple .................................................................................................... 11
10 Switching Waveform ...................................................................................................... 12
11 Switching Waveform ...................................................................................................... 12
12 Top Assembly.............................................................................................................. 13
13 Bottom Assembly.......................................................................................................... 13
14 Top Layer................................................................................................................... 14
15 Bottom Layer............................................................................................................... 14
16 Internal Layer 1............................................................................................................ 15
17 Internal Layer 2............................................................................................................ 15
List of Tables
1 TPS53129EVM-621 Electrical and Performance Specifications...................................................... 2
2 TPS53129EVM-621 Test Points Description............................................................................ 4
3 TPS53129EVM-621 Bill of Materials.................................................................................... 16
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Introduction www.ti.com
1 Introduction
1.1 Description
The TPS53129EVM-621 evaluation board provides the user with a convenient way to evaluate the
TPS53129 Dual D-CAP2™ Mode Control Step-Down Controller in a realistic cost-sensitive application.
Providing both a low core-type 1.05-V and I/O type 1.8-V output at up to 4 A from a loosely regulated 12-V
(8-V to 22-V) source, the TPS53129EVM-621 includes switches and test points to assist users in
evaluating the performance of the TPS53129 controller in their application.
1.2 Application
• Digital television
• Set-top box
• DSL and cable modems
• Cost-sensitive digital consumer products
1.3 Features
• 8-V to 22-V input
• 1.05-V and 1.8-V output
• Up to 4 A per channel output
• 700-kHz pseudo-fixed frequency D-CAP2™ mode control
• Independent enable switches for power-on/power-off testing
2 Electrical Performance Specifications
Table 1. TPS53129EVM-621 Electrical and Performance Specifications
Parameter Notes and Conditions MIN TYP MAX UNIT
INPUT CHARACTERISTICS
VIN Input Voltage 8 12 22 V
IIN Input Current VIN = 12 V, IOUT1 = 4 A, IOUT2 = 4 A – 1.2 1.5 A
No-Load Input Current VIN = 12 V, IOUT = 0 A – 20 – mA
VIN_UVLO Input UVLO IOUT = 4 A 4.0 4.2 4.5 V
OUTPUT CHARACTERISTICS
VOUT1 Output Voltage 1 VIN = 12 V, IOUT1 = 2 A – 1.05 – V
Line Regulation VIN = 8 V to 22 V – – 1%
Load Regulation IOUT1 = 0 A to 4 A – – 1%
VOUT1_rip Output Voltage Ripple VIN = 12 V, IOUT2 = 4 A – - 30 mVpp
IOUT1 Output Current 1 VIN = 8 V to 22 V 0 4 A
VOUT2 Output Voltage 2 VIN = 12 V, IOUT2 = 2 A – 1.80 – V
Line Regulation VIN = 8 V to 22 V – – 1%
Load Regulation IOUT2 = 0 A to 4 A – – 1%
VOUT2_rip Output Voltage Ripple VIN = 12 V, IOUT2 = 4 A – – 30 mVpp
IOUT2 Output Current 2 VIN = 8 V to 22 V 0 4 A
SYSTEMS CHARACTERISTICS
FSW Switching Frequency 350 700 800 kHz
ηpk1 Peak Efficiency of Output 1 VIN = 12 V – 85% –
η1 Full-Load Efficiency of Output 1 VIN = 12 V, IOUT1 = 4 A – 84% –
ηpk2 Peak Efficiency of Output 2 VIN = 12 V – 89% –
η2 Full-Load Efficiency of Output 2 VIN = 12 V, IOUT2 = 4 A – 88% –
D-CAP2 is a trademark of Texas Instruments.
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+
+
+
www.ti.com Schematics
3 Schematics
NOTE: For Reference Only, See Table 3 for Specific Values.
Figure 1. TPS53129EVM-621 Schematic
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Connector and Test Point Descriptions www.ti.com
4 Connector and Test Point Descriptions
4.1 Enable Switches – SW1 and SW2
TPS53129EVM-621 includes independent enable switches for each of the two outputs. When the switch is
in the DIS position, the channel is disabled and discharged per the TPS53129’s internal discharge
characteristics.
To enable VOUT1, place SW1 in the EN position. To enable VOUT2, place SW2 in the EN position.
4.2 Switching Frequency Select Switch – SW3
TPS53129EVM-621 does not populate SW3. When using TPS53129EVM-621 to evaluate the TPS53126
controller in the TSSOP package, SW3 can be populated to allow selection of the TPS53126 switching
frequency between 350 kHz and 700 kHz.
4.3 Test Point Descriptions
Table 2 lists the test points, their labels, uses, and where additional information is located.
Table 2. TPS53129EVM-621 Test Points Description
Test Point Label Use Section
TP1 SS1 Monitor Channel-1 Soft-Start Voltage Section 4.3.4
TP2 SS2 Monitor Channel-2 Soft-Start Voltage Section 4.3.4
TP3 GND Ground for Input Voltage Section 4.3.1
TP4 GND Ground for Channel-1 Output Voltage Section 4.3.2
TP5 SW1 Monitor Switching Node for Channel 1 Section 4.3.5
TP6 GND Ground for Channel-2 Output Voltage Section 4.3.3
TP7 VOUT2 Monitor Output Voltage for Channel 2 Section 4.3.3
TP8 VOUT1 Monitor Output Voltage for Channel 1 Section 4.3.2
TP9 VIN Monitor Input Voltage Section 4.3.1
TP10 VREG5 Monitor Output of VREG5 Regulator Section 4.3.6
TP11 SW2 Monitor Switching Node for Channel 2 Section 4.3.5
4.3.1 Input Voltage Monitoring – TP3 and TP9
TPS53129EVM-621 provides two test points for measuring the voltage applied to the module. This allows
the user to measure the actual module voltage without losses from input cables and connectors. Measure
all input voltage between TP9 and TP3. To use TP9 and TP3, connect a voltmeter positive terminal to TP9
and negative terminal to TP3.
4.3.2 Channel-1 Output Voltage Monitoring – TP4 and TP8
TPS53129EVM-621 provides two test points for measuring the voltage generated at the VOUT1 output by
the module. This allows the user to measure the actual output voltage without losses from output cables
and connectors. Measure all dc output voltage measurements between TP8 and TP4. To use TP8 and
TP4, connect a voltmeter positive terminal to TP8 and negative terminal to TP4.
For output ripple measurements, TP8 and TP4 allow a user to limit the ground loop area by using the tip
and barrel measurement technique shown in Figure 2.
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TP4TP8
Metal Ground Barrel
Probe Tip
www.ti.com Test Setup
Figure 2. Tip and Barrel Measurement for Output Voltage Ripple
4.3.3 Channel-2 Output Voltage Monitoring – TP6 and TP7
TPS53129EVM-621 provides two test points for measuring the voltage generated at the VOUT2 output by
the module. This allows the user to measure the actual output voltage without losses from output cables
and connectors. Measure all dc output voltage between TP7 and TP6. To use TP7 and TP6, connect a
voltmeter positive terminal to TP7 and negative terminal to TP6.
For output ripple measurements, TP7 and TP6 allow a user to limit the ground loop area by using the tip
and barrel measurement technique shown in Figure 2.
4.3.4 Soft-Start Voltage Monitoring – TP1, TP2, and TP3
TPS53129EVM-621 provides two test points for measuring the soft-start ramp voltages. TP1 monitors the
soft-start ramp of Channel 1. TP2 monitors the soft-start ramp of Channel 2. To use TP1 or TP2, connect
an oscilloscope probe between TP1 or TP2 and TP3.
4.3.5 Switching Node Monitoring – TP3, TP5, and TP11
TPS53129EVM-621 provides two test points for measuring the switching node waveform voltages. TP5
monitors the switching node of Channel 1. TP2 monitors the switching node of Channel 2. To use TP5 or
TP11, connect an oscilloscope probe between TP5 or TP11 and TP3.
4.3.6 5-V Regulator Output Monitoring – TP3 and TP10
TPS53129EVM-621 provides a test point for measuring the output of the internal 5-V regulator. TP10
monitors the output voltage of the internal 5-V regulator. To use TP10, connect a voltmeter positive
terminal to TP10 and negative terminal to TP3.
5 Test Setup
5.1 Equipment
5.1.1 Voltage Source
Use an input voltage source (VIN) of 0-V to 25-V variable dc source capable of supplying 2 Adc minimum.
5.1.2 Meters
A1: 0-Adc to 5-Adc, ammeter
V1: VIN, 0-V to 25-V voltmeter
V2: VOUT1, 0-V to 2-V voltmeter
V3: VOUT2, 0-V to 2-V voltmeter
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Test Setup www.ti.com
5.1.3 Loads
LOAD1: One output load is an electronic load set for constant-current mode capable of 0 Adc to 4 Adc at
1.05 Vdc.
LOAD2: The other output load is an electronic load set for constant-current mode capable of 0 Adc to 4
Adc at 1.8 Vdc.
5.1.4 Oscilloscope and Probe
The oscilloscope, analog or digital, must be set for ac-coupled measurement with 20-MHz bandwidth
limiting. Use 20-mV/division vertical resolution, 1-µs/division horizontal resolution for output ripple voltage
test.
Oscilloscope probes with exposed conductive ground barrels are recommended.
5.1.5 Recommended Wire Gauge
VIN to J3 – The connection between the source voltage VIN and J1 of TPS53129EVM-621 can carry as
much as 2 Adc. The minimum recommended wire size is AWG 16 with the total length of wire less than 2
feet (1-foot input, 1-foot return).
J1 to LOAD1 and J2 to LOAD2 – The connection between J1 and LOAD1, and J2 and LOAD2 of
TPS53129EVM-621 can carry as much as 4 Adc each. The minimum recommended wire size is AWG 14
with the total length of wire less than 2 feet (1-foot input, 1-foot return).
5.1.6 Other Test Equipment
FAN – The TPS53129EVM-621 evaluation module includes components that can become hot to the
touch. Because this EVM is not enclosed to allow probing of circuit nodes, a small fan capable of 200-400
lfm is recommended to reduce component temperatures when operating.
5.2 Recommended Setup
Figure 3 shows the recommended test setup to evaluate the TPS53129EVM-621. Working at an ESD
workstation, ensure that any wrist straps, bootstraps, or mats are connected referencing the user to earth
ground before power is applied to the EVM. An electrostatic smock and safety glasses also are
recommended.
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LOAD1
1.05V @
4A V2
+
-
LOAD2
1.8V @
4A V3
-
+
-
+
-
+
A1
-
+
V
VIN
V1
+-
FAN
www.ti.com Test Procedure
Figure 3. TPS53129EVM-621 Recommended Test Setup
6 Test Procedure
6.1 Start-Up Procedure
1. Prior to connecting the dc input source VIN, it is advisable to limit the source current from VIN to 2 Adc
maximum. Ensure that VIN is initially set to 0 V.
2. Ensure that LOAD1 and LOAD2 are set to constant-current mode to sink 0 A before VIN is applied.
3. Verify that SW1 and SW2 are in the desired position.
4. Place a fan as shown in Figure 3 and turn on, making sure that air is flowing across the EVM.
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Performance Data and Typical Characteristic Curves www.ti.com
5. Increase VIN from 0 Vdc to 12 Vdc.
6.2 Line/Load Regulation and Efficiency Measurement Procedure
1. Set up the TPS53129EVM-621 per Section 5.2.
2. Start up the TPS53129EVM-621 per Section 6.1.
3. Adjust VIN to desired value between 8 Vdc and 22 Vdc.
4. Adjust LOAD1/LOAD2 to desired load between 0 Adc and 4 Adc.
5. Read input voltage, output voltage, and input current from V1, V2/V3, and A1, respectively.
6. Shut down the TPS53129EVM-621 per Section 6.4.
6.3 Output Ripple Voltage Measurement Procedure
1. Set up the TPS53129EVM-621 per Section 5.2.
2. Start up the TPS53129EVM-621 per Section 6.1.
3. Adjust VIN to desired value between 8 Vdc and 22 Vdc.
4. Adjust LOAD1/LOAD2 to desired load between 0 Adc and 4 Adc.
5. Connect the oscilloscope probe to TP8 and TP4 for VOUT1, or TP7 and TP6 for VOUT2 as shown in
Figure 2.
6. Measure output ripple.
7. Shut down the TPS53129EVM-621 per Section 6.4.
6.4 Shutdown Procedure
1. Set SW1 to DIS.
2. Set SW2 to DIS.
3. Decrease LOAD1 to 0 A, and shut down LOAD1.
4. Decrease LOAD2 to 0 A, and shut down LOAD2.
5. Decrease VIN to 0 V, and shut down VIN.
6. Shut down the fan.
7 Performance Data and Typical Characteristic Curves
Figure 4 through Figure 11 present typical performance curves for the TPS53129EVM-621. Because
actual performance data can be affected by measurement techniques and environmental variables, these
curves are presented for reference and may differ from actual field measurements.
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012345
I - Load Current - A
LOAD
V = 8 V
I
50
55
60
65
70
75
80
85
90
h- Efficiency - %
V = 12 V
I
V = 22 V
I
V = 8 V-22 V,
V = 1.05 V,
I = 0 A-4 A
I
OUT1
OUT1
50
55
60
65
70
75
80
85
90
95
h- Efficiency - %
0 1 2 3 4 5
I - Load Current - A
LOAD
V = 8 V
I
V = 12 V
I
V = 22 V
I
V = 8 V-22 V,
V = 1.8 V,
I = 0 A-4 A
I
OUT2
OUT1
www.ti.com Performance Data and Typical Characteristic Curves
7.1 Efficiency
Figure 4. Efficiency vs Load
Figure 5. Efficiency vs Load
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012345
I - Load Current - A
LOAD
V = 8 V
I
V = 12 V
I
V = 22 V
I
V = 8 V-22 V,
V = 1.05 V,
I = 0 A-4 A
I
OUT1
OUT1
1.044
1.046
1.048
1.05
1.052
1.054
1.056
1.058
1.06
V - Output Voltage - V
O
1.795
1.8
1.805
1.81
1.815
1.82
1.825
1.83
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5
V - Output Voltage - V
O
I - Load Current - A
LOAD
V = 8 V
I
V = 12 V
I
V = 22 V
I
V = 8 V-22 V,
V = 1.8 V,
I = 0 A-4 A
I
OUT2
OUT2
Performance Data and Typical Characteristic Curves www.ti.com
7.2 Line and Load Regulation
Figure 6. Output Voltage vs Load
Figure 7. Output Voltage vs Load
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