Texas Instruments LM5122EVM-2PH User Manual

LM5122EVM-2PH Evaluation Module
User's Guide
Literature Number: SNVU205
APRIL 2013
Contents
1 Introduction ........................................................................................................................ 4
2 Features and Electrical Performance ..................................................................................... 4
3 Test Points ......................................................................................................................... 4
3.1 Test Points ............................................................................................................... 4
4 Test Equipment ................................................................................................................... 5
4.2 Electronic Load .......................................................................................................... 5
4.3 Meters ..................................................................................................................... 5
4.4 Oscilloscope .............................................................................................................. 5
5 Test Setup and Procedure .................................................................................................... 5
5.1 Precaution & Wire Gauge .............................................................................................. 5
5.3 Quick Test Procedure ................................................................................................... 6
6 Performance Curves ............................................................................................................ 6
6.1 Efficiency ................................................................................................................. 6
6.2 Load Transient ........................................................................................................... 7
6.4 Light Load Operations .................................................................................................. 8
6.5 Startup .................................................................................................................... 9
6.6 Loop Response .......................................................................................................... 9
7 Schematic ......................................................................................................................... 10
8 Layout .............................................................................................................................. 12
9 Bill of Materials ................................................................................................................. 15
2
Table of Contents SNVU205–APRIL 2013
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1 Connection Diagram........................................................................................................ 5
2 Efficiency..................................................................................................................... 6
3 Load Transient .............................................................................................................. 7
4 Interleaving................................................................................................................... 7
5 Pulse Skip.................................................................................................................... 8
6 Skip Cycle.................................................................................................................... 8
7 Forced PWM................................................................................................................. 8
8 Startup........................................................................................................................ 9
9 Loop Response.............................................................................................................. 9
10 Schematic (Power Block)................................................................................................. 10
11 Schematic (Control Block)................................................................................................ 11
12 Top Silk (Top View) ....................................................................................................... 12
13 Bottom Silk (X-Ray View) ................................................................................................ 12
14 Top Copper (Top View)................................................................................................... 13
15 Mid1 Copper (X-Ray View)............................................................................................... 13
16 Mid2 Copper (X-Ray View)............................................................................................... 14
17 Bottom Copper (X-Ray View)............................................................................................ 14
List of Figures
List of Tables
1 Electrical Performance Specifications.................................................................................... 4
2 Pin Descriptions............................................................................................................. 4
3 Bill of Materials............................................................................................................. 15
SNVU205–APRIL 2013 List of Figures
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3
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LM5122EVM-2PH Evaluation Module
1 Introduction
The LM5122EVM-2PH evaluation module (EVM) provides the design engineer with a fully functional dual phase synchronous boost converter to evaluate the Texas Instruments LM5122 synchronous boost controller device. The EVM provides 28 V output at up to 7 A current from a 9 V to 20 V input. The EVM is designed to start up from a single power supply without any additional bias voltage.
2 Features and Electrical Performance
9 V to 20 V input voltage range
28 V target output voltage
Up to 7 A output current
250 kHz typical switching frequency
Dual phase interleaved operation
Table 1. Electrical Performance Specifications
PARAMETER TEST CONDITIONS MIN TYP MAX UNITS
Input Characteristics
Input Voltage 9 12 20 V Input Current V
Output Characteristics
Output Voltage I Output Current 7 A
System Characteristics
Switching Frequency 250 kHz Full Load Efficiency V
= 12 V, I
SUPPLY
= 7A 27.02 28 28.98 V
LOAD
= 12 V 96%
SUPPLY
V
= 20 V 98%
SUPPLY
= 7A 17 A
LOAD
User's Guide
SNVU205–APRIL 2013
3 Test Points
3.1 Test Points
PIN NAME DESCRIPTIONS
TP7, TP8 Power Ground
TP5, TP9, TP10 Analog Ground
TP6 UVLO J1#1 External Synchronization Pulse Positive Input J1#2 External Synchronization Pulse Negative Input
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LM5122EVM-2PH Evaluation Module SNVU205–APRIL 2013
Table 2. Pin Descriptions
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Oscilloscope
A
COM
Ampere Meter
+-
Power Supply
Electronic Load
+-
V
Voltage Meter
COM
-s +s
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4 Test Equipment
4.1 Power Supply
Power Supply should be capable of 20 V / 25 A, current monitoring and remote sensing.
4.2 Electronic Load
Electronic load should be capable of 32 V / 7 A. Use Constant Current (CC) mode.
4.3 Meters
One current meter is required to measure input current accurately. Maximum current rating of the meter should be carefully considered. Input current can be as high as 25 A at full load current and minimum input voltage. Output voltage is monitored by a voltage meter which should be capable of monitoring up to 32 V.
4.4 Oscilloscope
Oscilloscope and 10x probe with at least 20 MHz bandwidth are required.
5 Test Setup and Procedure
Test Equipment
5.1 Precaution & Wire Gauge
Prolonged operation with low input voltage at full power will cause heating of the MOSFETs. A fan with a minimum of 200LFM should be always provided.
Wire gauge for the input power supply should be 6-8 AWG minimum and no longer than 1 foot each for VIN and GND. Wire gauge for the output electronic load should be 12 AWG minimum and no longer than 1 foot each for VOUT and GND.
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Figure 1. Connection Diagram
5
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80
85
90
95
100
0 2 4 6 8
EFFICIENCY [%]
LOAD CURRENT [A]
C001
FSW = 250 kHz
V
OUT
= 28V
V
SUPPPLY
= 20V
V
SUPPLY
= 9V
V
SUPPLY
= 12V
Performance Curves
5.2 Test Setup
5.2.1 Power Supply
Connect the power supply’s positive terminal (+) to ‘A’ terminal of ampere meter and negative terminal (-) to TP4 GND. Connect the power supply’s positive remote sense terminal to TP2 VIN and negative remote sense terminal to TP4 GND.
5.2.2 Meter
Connect ‘COM’ terminal of ampere meter to TP2 VIN. Double check ‘A’ terminal is connected to the power supply’s positive terminal.
Voltage meter is used to measure output voltage. Connect positive terminal (V) of the voltage meter to TP1 VOUT and negative terminal (COM) of the voltage meter to TP3 GND.
5.2.3 Load
Connect electronic load’s positive terminal (+) to TP1 VOUT and negative terminal (-) to TP3 GND.
5.3 Quick Test Procedure
5.3.1 Startup
Set load current to 0 A and turn the load on
Set power supply current limit to 25 A
Turn on the power supply and increase voltage slowly up to 20 V
Increase load current slowly up to 7 A
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5.3.2 Shutdown
Turn off the load
Decrease the input voltage down to 0 V
Turn on the load and discharge output capacitor
6 Performance Curves
The following curves are presented for reference, the actual field data may differ from these curves. Actual performance data can be affected by measurement techniques, equipment setting and environmental variables.
6.1 Efficiency
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LM5122EVM-2PH Evaluation Module SNVU205–APRIL 2013
Figure 2. Efficiency
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