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Test Setup
5.2
Recommended Test Setup
90 - 265
VRMS
AC Source
L
N
CL1
Current Probe:
PFC inductor
ripple current
monitor
TP1 & TP2
Loop injection point
TP4 & TP5
PFC output voltage
CL2
Current Probe:
Buck inductor
ripple current
monitor
Constant
Voltage
Load
+
-
1000uF
250V
V2
A1
IEC320
-C13
Plug
+
V1
J2
Pin 1: PFC Shutdown
Pin 2: GND
TP3
Buck bias voltage monitor
J3
Short pins to Enable
On Board Dimming
J4
Pin 1: Buck Shutdown
Pin 2: GND
Pin 3 External PWM dimming input
Figure 3. UCC28810EVM-002 Recommended Test Set Up
Note:
The 1000-µF/250-V capacitor on the output is not required if the load is a string of HB-LED’s.
5.3
List of Test Points
Table 2. Test Point Functions
TEST POINTS
TP1
TP2
TP3
TP4
TP5
TP6
TP7
TP8
TP9
TP10
TP11
J2-1
J2-2
J4-1
J4-2
J4-3
J3
VCC_BK
PFC+
PFC-
VCC_BK
GND
GND
EN
GND
BK_IN
PFC shutdown
GND
BK_Shutdown
GND
PWM Dim
On board dim
Input for external PWM dimming
Short the two pins on J3 to enable on board PWM diming. R26
varies dimming duty cycle
Apply 3.3 V to this pin to shutdown buck stage
NAME
Loop injection point
Loop injection point, PFC output
Buck bias voltage output
PFC output voltage
PFC output voltage ground
Buck bias voltage input
Buck bias voltage ground
Ground connection
Buck enable
Buck input voltage ground
Buck input voltage
Apply 3.3 V to this pin to shutdown PFC stage
DESCRIPTION
SLUU355A – March 2009 – Revised June 2009
A 0.9-A Constant Current Supply with PFC for 100-W LED Lighting Applications
7
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