DS3881 Datasheet, PDF (19/28 Pages) Maxim Integrated Products – Single-Channel Automotive CCFL Controller

Single-Channel Automotive CCFL Controller
Table 4a. Soft-Start Protocol Registers (SSPx) [Shadowed-EEPROM, F0h, F1h, F2h, F3h]
SSP#
SSP1
SSP2
SSP3
SSP4
ADDR
F0h
F1h
F2h
F3h
FACTORY
DEFAULT
21h
43h
65h
77h
MSB
7
LST1
RSVD
RSVD
RSVD
6
5
4
Lamp Cycles 3 and 4
Lamp Cycles 7 and 8
Lamp Cycles 11 and 12
Lamp Cycles 15 and 16
3
LST0
RSVD
RSVD
RSVD
LSB
2
1
0
Lamp Cycles 1 and 2
Lamp Cycles 5 and 6
Lamp Cycles 9 and 10
Lamp Cycles 13 and 14
Table 4b. MOSFET Duty Cycle (MDC)Codes for Soft-Start Settings
BIT R/W NAME
FUNCTION
0 R/W
MDC0
1 R/W
MDC1
2 R/W
MDC2
3 R/W LST0 / RSVD
MDC0/1/2/3: These bits determine a MOSFET duty cycle that repeats twice in the
16 lamp cycle soft-start.
MDC CODE
0h
1h
2h
3h
MOSFET DUTY CYCLE
Fixed at 0%
Fixed at 3%
Fixed at 6%
Fixed at 9%
MDC CODE
4h
5h
6h
7h
MOSFET DUTY CYCLE
Fixed at 13%
Fixed at 16%
Fixed at 19%
Most Recent Value
4 R/W
MDC0
5 R/W
MDC1
6 R/W
MDC2
7 R/W LST1 / RSVD
LST1
0
0
1
1
LST0/1: These bits select strike and lamp out timeout. LST0 and LST1
control fault behavior for all lamps.
LST0
STRIKE AND LAMP OUT TIMEOUT
(LAMP FREQUENCY CYCLES)
EXAMPLE TIMEOUT IF
LAMP FREQUENCY IS 50kHz
0
32,768
1
65,536
0
98,304
1
131,072
0.66 seconds
1.31 seconds
1.97 seconds
2.62 seconds
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