LP39542 Datasheet, PDF (14/58 Pages) National Semiconductor (TI) – Advanced Lighting Management Unit

Command Based Pattern Generator
for Color LEDs
The LP39542 has an unique stand-alone command based
pattern generator with 8 user controllable 16-bit commands.
Since registers are 8-bit long one command requires 2 write
cycles. Each command has intensity level for each LED, com-
mand execution time (CET) and transition time (TT) as seen
in the following figures.
30008519
COMMAND REGISTER WITH 8 COMMANDS
COMMAND 1 ADDRESS 50H R2
R1
R0
G2
G1
G0 CET3 CET2
ADDRESS 51H CET1 CET0 B2
B1
B0
TT2 TT1 TT0
COMMAND 2 ADDRESS 52H R2
R1
R0
G2
G1
G0 CET3 CET2
ADDRESS 53H CET1 CET0 B2
B1
B0
TT2 TT1 TT0
COMMAND 3 ADDRESS 54H R2
R1
R0
G2
G1
G0 CET3 CET2
ADDRESS 55H CET1 CET0 B2
B1
B0
TT2 TT1 TT0
COMMAND 4 ADDRESS 56H R2
R1
R0
G2
G1
G0 CET3 CET2
ADDRESS 57H CET1 CET0 B2
B1
B0
TT2 TT1 TT0
COMMAND 5 ADDRESS 58H R2
R1
R0
G2
G1
G0 CET3 CET2
ADDRESS 59H CET1 CET0 B2
B1
B0
TT2 TT1 TT0
COMMAND 6 ADDRESS 5AH R2
R1
R0
G2
G1
G0 CET3 CET2
ADDRESS 5BH CET1 CET0 B2
B1
B0
TT2 TT1 TT0
COMMAND 7 ADDRESS 5CH R2
R1
R0
G2
G1
G0 CET3 CET2
ADDRESS 5DH CET1 CET0 B2
B1
B0
TT2 TT1 TT0
COMMAND 8 ADDRESS 5EH R2
R1
R0
G2
G1
G0 CET3 CET2
ADDRESS 5FH CET1 CET0 B2
B1
B0
TT2 TT1 TT0
COLOR INTENSITY CONTROL
Each color has 3-bit intensity level. Level control is logarith-
mic, 2 curves are selectable. The LOG bit in register 11H
defines the curve used as seen in the following table.
R[2:0], G[2:0],
B[2:0]
CURRENT
[% × I_MAX(COLOR)]
LOG=0
LOG=1
000
0
0
001
7
1
010
14
2
011
21
4
100
32
10
101
46
21
110
71
46
111
100
100
30008520
www.national.com
14