Texas Instruments UCC28742EVM-001 User manual

Using the UCC28742EVM-001 10-W Converter
User's Guide
Literature Number: SLUUBU4B
March 2018–Revised June 2018

WARNING
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General Texas Instruments High Voltage Evaluation (TI HV EVM) User Safety Guidelines
Always follow TI’s setup and application instructions, including use of all interface components within their
recommended electrical rated voltage and power limits. Always use electrical safety precautions to help
ensure your personal safety and those working around you. Contact TI's Product Information Center
http://support/ti./com for further information.
Save all warnings and instructions for future reference.
Failure to follow warnings and instructions may result in personal injury, property damage, or
death due to electrical shock and burn hazards.
The term TI HV EVM refers to an electronic device typically provided as an open framed, unenclosed
printed circuit board assembly. It is intended strictly for use in development laboratory environments,
solely for qualified professional users having training, expertise and knowledge of electrical safety
risks in development and application of high voltage electrical circuits. Any other use and/or
application are strictly prohibited by Texas Instruments. If you are not suitable qualified, you should
immediately stop from further use of the HV EVM.
1. Work Area Safety
1. Keep work area clean and orderly.
2. Qualified observer(s) must be present anytime circuits are energized.
3. Effective barriers and signage must be present in the area where the TI HV EVM and its interface
electronics are energized, indicating operation of accessible high voltages may be present, for the
purpose of protecting inadvertent access.
4. All interface circuits, power supplies, evaluation modules, instruments, meters, scopes and other
related apparatus used in a development environment exceeding 50Vrms/75VDC must be
electrically located within a protected Emergency Power Off EPO protected power strip.
5. Use stable and nonconductive work surface.
6. Use adequately insulated clamps and wires to attach measurement probes and instruments. No
freehand testing whenever possible.
2. Electrical Safety
As a precautionary measure, it is always a good engineering practice to assume that the entire EVM
may have fully accessible and active high voltages.
1. De-energize the TI HV EVM and all its inputs, outputs and electrical loads before performing any
electrical or other diagnostic measurements. Revalidate that TI HV EVM power has been safely
de-energized.
2. With the EVM confirmed de-energized, proceed with required electrical circuit configurations,
wiring, measurement equipment connection, and other application needs, while still assuming the
EVM circuit and measuring instruments are electrically live.
3. After EVM readiness is complete, energize the EVM as intended.
WARNING: WHILE THE EVM IS ENERGIZED, NEVER TOUCH THE EVM OR ITS ELECTRICAL
CIRCUITS AS THEY COULD BE AT HIGH VOLTAGES CAPABLE OF CAUSING ELECTRICAL
SHOCK HAZARD.
3. Personal Safety
1. Wear personal protective equipment (for example, latex gloves or safety glasses with side shields)
or protect EVM in an adequate lucent plastic box with interlocks to protect from accidental touch.
Limitation for safe use:
EVMs are not to be used as all or part of a production unit.

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Using the UCC28742EVM-001 10-W Converter
User's Guide
SLUUBU4B–March 2018–Revised June 2018
Using the UCC28742EVM-001 10-W Converter
1 Description
The UCC28742EVM-001 is a 10-W evaluation module for evaluating an off-line power converter
applications. The EVM meets CoC tier 2 and DoE Level 6 efficiency and standby power requirements. It is
intended for evaluation purposes and is not intended to be an end product. The UCC28742EVM-001
converters 85-VRMS to 265-VRMS input voltage down to 5-VDC, with a 2.1-A current limit.
Figure 1. UCC28742EVM-001

Electrical Performance Specifications www.ti.com
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2 Electrical Performance Specifications
Table 1. UCC28742EVM-001 Electrical Performance Specifications
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
INPUT CHARACTERISTICS
VIN Input voltage (RMS) 85 115/230 265 V
fLINE Line frequency 47 50/60 63 Hz
PSTBY No load input power VIN = 115 V / 230 V RMS, IOUT = 0 A 75 mW
OUTPUT CHARACTERISTICS
VOUT Output voltage VIN = nom, IOUT = nom 4.75 5.25 V
VOUT Output ripple voltage VIN = nom, IOUT = max, 50 mVpp
IOUT Output current VIN = min to max 2 2.05 A
Over Current Shut Down VIN = min to max 2.1 A
Load step 0 A to 0.5 A 4.1 6 V
SYSTEMS CHARACTERISTICS
η4-point average efficiency 25%, 50%, 75% and 100% load, 115-V / 230-V
RMS input 82%
η10% Efficiency 115-V / 230-V RMS input 78
Operating temperature
range VIN = min to max, IOUT = min to max 25 °C

www.ti.com Schematic
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3 Schematic
Figure 2. UCC28742EVM-001 Schematic

AC Line
AC Neutral
VOUT +
VOUT -
Isolated
Variable AC
Source
1 ohm
Precision Shunt
Current
Measurement
Voltage
Measurement
Power Analyzer
Load
UCC28742EVM-001
TP1
TP2
TP3
TP4
Volt Meter
Oscilloscope
100nF
Scope
Probe
Test Setup www.ti.com
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4 Test Setup
4.1 Test Setup Requirements
Safety: This evaluation module is not encapsulated and there are voltages that are much greater than 50
VDC.
WARNING
If you are not trained in the proper safety of handling and testing
power electronics please do not test this evaluation module.
Voltage Source: Isolated AC source or variable AC transformer capable of 265 VAC cable of handling 10
W
Voltmeter: Digital voltage meter
Power Analyzer: Capable of measuring 1 mW to 10 W of input power and capable of handling 265-V
RMS input voltage. Some power analyzers may require a precision shunt resistor for measuring input
current to measure input power of 5 W or less. Please read the power analyzer’s user manual for proper
setup.
Oscilloscope:
• 4 Channel 100 MHz.
• Probes capable of handling 600 V.
Output Load: Resistive or electronic load capable handling 15 W at 5 V.
Recommended Wire Gauge: Insulated 22 AWG.
4.2 Test Setup Diagram
Figure 3. UCC28742EVM-001 Test Setup Diagram

Output Power
Efficiency (%)
10% 20% 30% 40% 50% 60% 70% 80% 90% 100%
60%
65%
70%
75%
80%
85%
D001D001
115 V RMS
230 V RMS
www.ti.com Test Points
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5 Test Points
Table 2. Test Point Functions
TEST POINTS NAME DESCRIPTION
TP1 L AC line voltage input
TP2 N AC neutral input
TP3 VOUT + Output supply
TP4 VOUT – Output return
6 Performance Data and Typical Characteristic Curves
6.1 Efficiency
Table 3. Efficiency Test Data
VIN RMS VOUT IOUT PIN EFFICIENCY
115 V 5.018 V 0.000 A 0.055 W N/A
115 V 5.017 V 0.201 A 1.268 W 79.5%
115 V 5.015 V 0.501 A 3.072 W 81.8%
115 V 5.014 V 1.002 A 6.124 W 82.0%
115 V 5.013 V 1.500 A 9.183 W 81.9%
115 V 5.011 V 2.004 A 12.244 W 82.0%
230 V 5.019 V 0.000 A 0.072 W N/A
230 V 5.017 V 0.201 A 1.317 W 76.6%
230 V 5.015 V 0.501 A 3.086 W 81.4%
230 V 5.015 V 1.002 A 6.097 W 82.4%
230 V 5.013 V 1.500 A 9.121 W 82.5%
230 V 5.011 V 2.004 A 12.157 W 82.6%
Figure 4. Efficiency

VIN = 230V RMS
RLOAD = 2.5 Ohm
VIN = 230V RMS
RLOAD = Unloaded
VIN = 115V RMS
RLOAD = Unloaded
VIN = 115V RMS
RLOAD = 2.5 Ohm
VIN
VOUT
VAUX
VCS
VIN = 85V RMS
RLOAD = Unloaded
VIN = 85V RMS
RLOAD = 2.5 ohm
Performance Data and Typical Characteristic Curves www.ti.com
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6.2 Startup
CH1 = Aux (D4 Anode), CH2 = VOUT, CH3 = VRCS (R16) , CH4 = VIN (C1)
Figure 5. Figure 6.
Figure 7. Figure 8.
Figure 9. Figure 10.

VIN = 230V RMS
VIN = 265V RMS
VIN = 115V RMS
IOUT
VOUT
VAUX
VCS
VIN = 85V RMS
VIN = 265V RMS
RLOAD = Unloaded
VIN = 265V RMS
RLOAD = 2.5 Ohm
www.ti.com Performance Data and Typical Characteristic Curves
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Figure 11. Figure 12.
6.3 Load Transients
CH1 = Aux (D4 Anode), CH2 = VOUT, CH3 = VRCS (R16), CH4 = IOUT
Load = 0.100A to 2 A, 50 Hz, 50% Duty Cycle
Figure 13. Figure 14.
Figure 15. Figure 16.

VIN = 265V RMS
VQ1d, 100 X Probe
VAUX
VCS
VIN = 85V RMS
VOUT
VAUX
VCS
VIN = 265V RMS
Performance Data and Typical Characteristic Curves www.ti.com
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6.4 Output Ripple Voltage at Full Load
Figure 17. IOUT = 2A Figure 18. IOUT = 2 A
6.5 Q1 Drain Voltage Evaluation
Figure 19. IOUT = 2A