First LED power-on

AN4374

8/25

DocID025366 Rev 2

Figure 7. Digital key summary chart-write switch

Figure 8. Switch register, example 1

The result of above seventeen 16-bit words is the LED power-on at ILED = 3 mA and 100%

duty cycle.

CLK

LE

LE

LE

LE

LE

LE

LE

LE

LE

W

Write Switch

Data Latch

Global Latch

Write CR

Read CR

Start Open Error Detection

Start Short Error Detection

Start Combined Detection

End Error Detection

LE

Thermal Error Reading

AM16856v1

Clk

SDI

LE

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

first bit

last bit

Output switches: all output ON

(Output switch reg.= 0xFFFF)

Data signal is always high for 16 clock rising edges, LE is high for 1 clock rising edge

AM16857v1