Test Setup
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5
Test Setup
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. The use of isolated test equipment is highly
recommended.
5.1
Test Equipment
See
for recommended test set up.
5.1.1
Voltage Source:
•
Source 1:
Isolated AC voltage source or VARIAC, capable of 90 VRMS to 264 VRMS at 150 W.
•
Source 2:
A 3.3-V DC source capable of 100 mA.
Multimeters
Three digital multimeters are recommend, one for current measurement, A1, and two for voltage
measurements, V1 and V2.
5.1.2
5.1.3
Output Load
It is recommended that actual high brightness LED’s (HB-LED’s) are used for the load. They should be
rated at 0.9 A. The HB-LED’s should be connected in series. Their voltage drop should be between 55
VDC and 110 VDC. Alternatively a constant voltage electronic load could be used. If using a constant
voltage electronic load a 1000-µF/250 VDC capacitor is required at the input to the electronic load. The
1000
µF
capacitor should not be used if using HB-LED’s as the load.
5.1.4
Oscilloscope
A digital or analog oscilloscope with current probe is required to view the AC current in the PFC inductor
or buck inductor.
5.1.5
Signal Generator
A signal generator that can produce a square wave pulse train at between 200 Hz and 1 kHz is required
to do external PWM dimming.
5.1.6
Fan
Forced air cooling is not required
5.1.7
Recommended Wire Gauge
A minimum of 18 AWG wire is recommended. Also the wire connections between the AC source and the
EVM, and the EVM and load should be less than two feet long. The AC input connector accepts a
standard IEC320-C13 connector with ground pin.
6
A 0.9-A Constant Current Supply with PFC for 100-W LED Lighting Applications
SLUU355A – March 2009 – Revised June 2009
TI [ TEXAS INSTRUMENTS ]
