Ver1.0

13

LD1022

16 Channel Constant Current LED Driver

Current Adjust Mode

During current adjust mode, the system controller should send 16bit of data including the 8-bit current

adjust code (bit0 to bit7) to the SDI pin. Once LE holds high for 16 CLK cycles, sampling at every rising

edge of CLK, BCT5028 will re-direct the contents stored in the Shift Register to a 16-bit Configuration

Latch CR [15:0] rather than the 16-bit Output Latch in a Normal mode. Pin OE always enables the

output port no matter BCT5028 enters a Current Adjust mode or not.

1. Configuration Register (CR [15:0])

Current adjust code

bit0

bit1

bit2

bit3

bit4

bit5

bit6

bit7

bit8

bit9

bit10

bit11

bit12

bit13

bit14

bit15

255

1

1

1

1

1

1

1

1

254

0

1

1

1

1

1

1

1

253

1

0

1

1

1

1

1

1

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

1

1

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

bit setting

bit0

bit1

bit2

bit3

bit4

bit5

bit6

bit7

2. Current Gain Table

Default setting: FFh

Iout = [Bit_setting + 72] / [18*Rext]

Where Rext: External Resistor

Bit setting: Current Value

For Example:

Example 1:

If R-ext =360 ohm;

CR<7:0>=00H will provide 11.11mA

CR<7:0>=FFH will provide 50.46mA

Example 2:

If R-ext =1000 ohm;

CR<7:0>=00H will provide 4.00mA

CR<7:0>=FFH will provide 18.17mA