MAX1739EEP+ Maxim Integrated Products, MAX1739EEP+ Datasheet - Page 24

• Manufacturer Part Number: MAX1739EEP+
• Description: Display Drivers Wide Brightness Rang e CCFL Backlight Con
• Manufacturer: Maxim Integrated Products

Specifications of MAX1739EEP+

• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Wide Brightness Range
CCFL Backlight Controllers
X = Don’t care
The status register returns information on fault condi-
tions. If a lamp is not connected to the secondary of the
transformer, the MAX1739 will detect that the lamp cur-
rent has not exceeded the CSAV detection threshold
and after 2 seconds will clear the STATUS1 bit (see
Lamp-Out Detection). The STATUS1 bit is latched; i.e.,
it will remain 0 even if the lamp-out condition goes
away. When STATUS1 = 0, the lamp is forced off. STA-
TUS0 reports 1 as long as no overcurrent conditions
are detected. If an overcurrent condition is detected in
any given DPWM period, STATUS0 is cleared for the
duration of the following DPWM period. If an overcur-
Table 7. SHMD Register Bit Descriptions
Table 8. SH/SUS and SHMD Register Truth Table
Table 9. Status Register Bit Descriptions (Read Only/Writes Have No Effect)
24
BIT
BIT
2
1
0
1
0
______________________________________________________________________________________
SH/SUS
STATUS1
STATUS0
SHMD2
SHMD1
SHMD0
NAME
NAME
0
0
1
1
X
[STATUS1–STATUS0] (POR = 0b11)
STATE
STATE
POR
POR
0
0
1
1
1
SHMD2
SHMD2 = 1 forces the lamp off and sets STATUS1. SHMD2 = 0 allows the lamp to operate, though it
may still be shut down by the SH/SUS pin (depending on the state of SHMD1 and SHMD0).
When SH /SUS = 0, this bit has no effect. SH/SUS = 1 and SHMD1 = 1 forces the lamp off and sets
STATUS1. SH /SUS = 1 and SHMD1 = 0 allow the lamp to operate, though it may still be shut down
by the SHMD2 bit.
When SH /SUS = 1, this bit has no effect. SH /SUS = 0 and SHMD0 = 1 forces the lamp off and sets
STATUS1. SH /SUS = 0 and SHMD0 = 0 allows the lamp to operate, though it may still be shut down
by the SHMD2 bit.
0
0
0
0
1
STATUS1 = 0 means that a lamp-out condition has been detected. The STATUS1 bit stays clear
even after the lamp-out condition has gone away. The only way to set STATUS1 is to shut off the
lamp by programming the mode register or by toggling SH/SUS.
STATUS0 = 0 means that an overcurrent condition was detected during the previous digital PWM
period. STATUS0 = 1 means that no overcurrent condition was detected during the previous digital
PWM period.
Status Register
SHMD1
X
X
0
1
X
rent condition is not detected in any given DPWM peri-
od, STATUS0 is set for the duration of the following dig-
ital DPWM period. Forcing the CCFL lamp off by
entering shutdown, writing to the mode register, or by
toggling SH/SUS sets STATUS1.
The ID registers return information on the manufacturer,
the chip ID, and the chip revision number. The
MAX1739 is the first-generation advanced CCFL con-
troller, and its ChipRev is 0x00. Reading from the MfgID
register returns 0x4D, which is the ASCII code for “M”
(for Maxim); the ChipID register returns 0x96. Writing to
these registers has no effect.
SHMD0
0
1
X
X
X
DESCRIPTION
DESCRIPTION
Operate
Shutdown, STATUS1 set
Operate
Shutdown, STATUS1 set
Shutdown, STATUS1 set
OPERATING MODE
ID Registers