5.2

Recommended Test Setup

TP3

Buckbiasvoltagemonitor

TP4&TP5

PFCoutputvoltage

TP1&TP2

Loopinjectionpoint

CL2

CurrentProbe:

Buckinductor

ripplecurrent

monitor

J3

ShortpinstoEnable

OnBoardDimming

+

L

N

V2

CL1

CurrentProbe:

PFCinductor

ripplecurrent

monitor

1000uF

250V

A1

V1

J4

Pin1:BuckShutdown

Pin2:GND

Pin3ExternalPWMdimminginput

J2

Pin1:PFCShutdown

Pin2:GND

IEC320

-C13

Plug

90-265

VRMS

ACSource

Constant

Voltage

Load

+

-

5.3

List of Test Points

www.ti.com

Test Setup

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.

Table 2. Test Point Functions

TEST POINTS

NAME

DESCRIPTION

TP1

Loop injection point

TP2

Loop injection point, PFC output

TP3

VCC_BK

Buck bias voltage output

TP4

PFC+

PFC output voltage

TP5

PFC-

PFC output voltage ground

TP6

VCC_BK

Buck bias voltage input

TP7

GND

Buck bias voltage ground

TP8

GND

Ground connection

TP9

EN

Buck enable

TP10

GND

Buck input voltage ground

TP11

BK_IN

Buck input voltage

J2-1

PFC shutdown

Apply 3.3 V to this pin to shutdown PFC stage

J2-2

GND

J4-1

BK_Shutdown

Apply 3.3 V to this pin to shutdown buck stage

J4-2

GND

J4-3

PWM Dim

Input for external PWM dimming

Short the two pins on J3 to enable on board PWM diming. R26

J3

On board dim

varies dimming duty cycle

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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