DS3882
Dual-Channel Automotive CCFL Controller
20 ____________________________________________________________________
Table 3. Status Register 2 (SR2) [SRAM, E1h]
BIT R/W
POWER-UP
DEFAULT
NAME FUNCTION
0 R 0 FAULT_RT
Fault Condition—Real Time. A real-time bit that indicates the current operating status
of channel 2.
0 = Normal condition
1 = Fault condition
1 R 0 FAULT_L
Fault Condition—Latched. A latched bit that is set when the channel enters a fault
condition. This bit is cleared when read regardless of the current state of fault.
2 R 0 STO_L
Lamp Strike Time Out—Latched. A latched bit that is set when the lamp fails to strike.
This bit is cleared when read.
3 R 0 OV_L
Overvoltage—Latched. A latched bit that is set when a lamp overvoltage is present
for at least 64 lamp cycles. This bit is cleared when read.
4 R 0 LOUT_L
Lamp Out—Latched. A latched bit that is set when a lamp out is detected. This bit is
cleared when read.
5 R 0 LOC_L
Lamp Overcurrent—Latched. A latched bit that is set when a lamp overcurrent is
detected. This bit is cleared when read.
6 R 0 RSVD Reserved. Could be either 0 or 1 when read.
7 R 0 RSVD Reserved. Could be either 0 or 1 when read.
Note 1: Writing to this register has no effect on it.
Note 2: See Figure 8 for more details on how the status bits are set.
Note 3: SR2 is cleared when any of the following occurs:
• V
CC
drops below the UVLO threshold
• the SVML or SVMH thresholds are crossed
• the PDN hardware pin goes high
• the PDNE software bit is written to a logic 1
• the channel is disabled by the CH2D control bit
Table 4. Brightness Lamp Current Register (BLC) [SRAM, E3h]
BIT R/W
FACTORY
DEFAULT
NAME FUNCTION
0 R/W 0 LC0
1 R/W 0 LC1
2 R/W 0 LC2
3 R/W 0 LC3
4 R/W 0 LC4
These five control bits determine the target value for the lamp current. 11111b is
35% of the nominal level and 00000b is 100% of the nominal level. These control
bits are used for fine adjustment of the lamp brightness.
5 R/W 0 CH1D
Channel 1 Disable
0 = Channel 1 enabled
1 = Channel 1 disabled
6 R/W 0 CH2D
Channel 2 Disable. Useful for dimming in two lamp applications.
0 = Channel 2 enabled
1 = Channel 2 disabled
7 R/W 0 SEEB
SRAM-Shadowed EEPROM Write Control
0 = Enables writes to EEPROM
1 = Disables writes to EEPROM
