WLEDs test board

AN2809

20/22

Table 5, Table 6 and Table 7 respectively describe the board’s jumper functions, switches

and test-points.

Table 5.

Test board jumper functions

Jumper

Function

Default position

J1

Two-position selector. Used in conjunction with SW1 to simulate

a fault on shorted LEDs on row1. When set to position 1, the D10

LED can be shorted by pressing SW1. When set to position 2,

both D9 and D10 LEDs can be shorted by pressing SW1.

1

J2

Two-position selector. Same function as J1 but related to row6

(D59 and D60 LEDs).

1

J3 to J7

PCB tin-drop jumpers, bottom-sided. Used to parallelize the

desired number of rows.

Open

J8

8-terminal connector. Used to interface the LED7706

demonstration board.

-

J9

PCB tin-drop jumper, bottom-sided. Used to provide the output

voltage of the boost section of LED7706 to the low-current (D1-

D60), top-sided WLEDs array.

Shorted

J10 to J15

Two-pin jumpers, top-sided. Used to access the LED strings to

perform row current monitoring and voltage threshold

measurement.

Shorted

J16 to J39

PCB tin-drop jumper, bottom-sided. Used to reduce the number

of active LEDs of each row by shorting unused diodes.

Open

Table 6.

Test board switch functions

Switch

Function

Default position

SW1

Used in conjunction with J1 to simulate a shorted LED fault

condition. See J1 function.

Open (released)

SW2

Used in conjunction with J2 to simulate a shorted LED fault

condition. See J2 function.

Open (released)

SW3

DIP switch. Used to individually break ROW1 through row6.

Used to simulate open LED fault or unused (floating) rows.

ON

Table 7.

Test board test-point functions

Test point

Function

TP1 to TP10

PCB test points, top-sided. Used to easily access each LED of ROW1 (D1-D10).

TP11 to TP20

PCB test points, top-sided. Used to easily access each LED of ROW6 (D51-D60).

TP21

PCB test point, top-sided. Auxiliary access to the output voltage.