Texas Instruments UCC28610EVM-474, User Manual

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EVM Test Set Up
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5 EVM Test Set Up
Figure 2 shows the equipment set up when measuring the input power consumption during no load. Note
the addition of the 10-
Ω shunt resistor in Figure 3 . During the no-load test, the power analyzer should be
set for long averaging in order to include several cycles of operation and an appropriate current scale
factor for using the external shunt must be used. Figure 3 shows the basic test set up recommended to
evaluate the UCC28610EVM-474 with a load.
WARNING
High voltages that may cause injury exist on this evaluation
module (EVM). Please ensure all safety procedures are followed
when working on this EVM. Never leave a powered EVM
unattended.
5.1 Test Equipment
See Figure 3 and Figure 4 for recommended test set ups.
• AC Input Source: The input source shall be an isolated variable AC source capable of supplying
between 85 V
RMS
and 265 V
RMS
at no less than 30 W and connected as shown in Figure 3 and
Figure 4 . For accurate efficiency calculations, a power meter should be inserted between the neutral
line of the AC source and the Neutral terminal of the EVM. For highest accuracy, connect the voltage
terminals of the power meter directly across the Line and Neutral terminals of the EVM.
• Load: For the output load, a programmable electronic load set to constant current mode and capable
of sinking 0 to 3 A
DC
at 12 V
DC
shall be used. For highest accuracy, V
OUT
can be monitored by
connecting a DC voltmeter, DMM V
1
, directly across the +Vout and – Vout terminals as shown in
Figure 3 and Figure 4 . A DC current meter, DMM A
1
, should be placed in series with the electronic
load for accurate output current measurements.
• Power Meter: The power analyzer shall be capable of measuring low input current, typically less than
10 mA, and a long averaging mode if low power standby mode input power measurements are to be
taken. An example of such an analyzer is the Voltech PM100 Single Phase Power Analyzer. To
measure the intermittent bursts of current and power drawn from the line during no-load operation, an
external 10-
Ω shunt, with a current scale factor of 10 A/V, was used at a high sample rate over an
extended period of time in order to display the averaged results (refer to Figure 3 ).
• Multimeters: Two digital multimeters are used to measure the regulated output voltage (DMM V
1
) and
load current (DMM A
1
).
• Oscilloscope: A digital or analog oscilloscope with a 500-MHz scope probe is recommended.
• Fan: Forced air cooling is not required.
• Recommended Wire Gauge: a minimum of AWG18 wire is recommended. The wire connections
between the AC source and the EVM , and the wire connections between the EVM and the load
should be less than two feet long.
8 UCC28610EVM-474 25-W Universal Off-Line Flyback Converter SLUU383B – November 2009 – Revised May 2011
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