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List of Test Points
7 List of Test Points
Table 2. Test Point Description
TEST POINTS NAME DESCRIPTION
TP1 VIN - Input return
TP2 VIN + Input supply
TP3, TP12 N/A Current loop injection point (20-mV injection max)
TP4 LED1 + LED string 1 supply
TP5 LED1 - LED string 1 return
TP6 LED2 + LED string 2 supply
TP7 LED2 - LED string 2 return
TP8 LED3 + LED string 3 supply
TP9 LED3 - LED string 3 return
TP10 LED4 + LED string 4 supply
TP11 LED4 - LED string 4 return
TP13 BIAS Positive input for 12-V bias supply
TP14 DIM PWM Dimming Input
TP15 BLON Back light on control (remove jp9 before using)
TP16 ICOMP Compensation output
TP17 GND Logic ground
TP18 N/A Current sense offset
8 Power On/Off Procedure
WARNING
Failure to follow the Power On/Off Procedure may result in
unexpected operation and/or irreversible damage to the EVM
and/or individual.
1. It is important to follow the power up and power down procedure to ensure the EVM does not get
damaged
2. This EVM was designed to show the performance of the UCC25710 in a four-string LED driver
application using an LLC resonant converter and does not include all the circuitry required for this
application.
(a) Generally this power converter would be preceded by an EMI filter and a PFC pre-regulator. The
complete system would also included input Under Voltage Lockout (UVLO) circuitry; which this
EVM does not.
3. Connect all bias supplies, loads and test equipment before applying power. Please look at Figure 3
and Figure 4 for examples of test setups that could be used.
4. The EVM was not designed to startup from 0-V input voltage. Please make sure the input voltage is
in-between 370 V and 410 V before applying the bias voltage.
5. Apply 370-V to 410-V DC to the input of the power converter with the 500-V DC source.
6. Set the 0-V to 20-V power supply to 12 V, (This powers the UCC25710 LLC controller).
7. When powering down the unit set the 0-V to 20-V DC supply to 0 V before powering down the 500-V
DC Supply.
8. Set the 500-V DC Supply to 0 V.
9. For safety before handling the EVM make sure there are not voltages present on the EVM greater than
50 V, (Observe Volt Meter 1 and Volt Meter 2).
9
SLUU487A–March 2011–Revised March 2011 98-W Resonant LLC, 4-String LED Driver
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