DocID025366 Rev 2

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AN4374

First LED power-on

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At the end of the above sequence a 16-bit word with global latch must be sent, see Figure 6.

Figure 6. Brightness register: last BRT word example

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The output switch enable has to be sent. 16 bits with SDI=1 on switch register have to

be sent to have all 16 outputs ON (see Table 2 and Figure 7 and Figure 8).

Table 2. Digital key summary-write switch

Number

#CLK rising edge when the LE is 1

Command description

11-2

Write switch (to turn on/off output

channels)

2

3-4

Brightness data latch

3

5-6

Brightness global latch

4

7

Write configuration register

5

8

Read configuration register

6

9

Start open error detection mode

7

10

Start short error detection mode

8

11

Start combined error detection mode

9

12

End error detection mode

10

13

Thermal error reading

11

14

Reserved

12

15

Reserved

Clk

SDI

LE

15 14 13 12 11 10 09 08 07 06 05 04 03 02 01 00

first bit

last bit

(BRT reg. output 0 = 0xFFFF)

Global Latch

Key

AM16855v1