BD9422EFV Datasheet, PDF (13/28 Pages) Rohm – White LED Driver for large LCD panel

BD9422EFV
Datasheet
●3.2 Protection Operation at FAIL Latch output (FAILMODE=L)
●3.2.1 List of the Threshold Function terminal（typ. condition）
Please decide the resistance divider of the various protection detection using the following table.
Protection
name
LED Open
LED short
Detection
Pin name
LEDx
LEDx
Detection
condition
LEDx < 0.2V
SS>3V
LEDx > 5×VLSP
SS>3V
PWM
High
High
Release
condition
LEDx > 0.2V
LEDx < 5×VLSP
PWM
High/Low
High/Low
Protection type
Stop the CH latch after the CP
charge is completed.
Stop the CH latch after the CP
charge is completed.
UVLO
UVLO
UVLO < 2.3V
―
UVLO > 2.5V
―
Stop the system
OVP
SCP
OVP
OVP
OVP > 2.43V
―
OVP < 2.4V
OVP < 0.2V
―
OVP > 0.2V
OCP
CS
CS > 0.45V
―
CS < 0.45V
It is possible to reset with the FAIL_RST terminal to release the latch stop.
―
Stop the N output
Stop the N output.
―
Stop the system after the CP
charge is completed.
―
Stop the N output under the
detection.（Pulse by Pulse）
●3.2.2 List of Protection function
Protection function
STB
LED Open
LED short
UVLO
DC/DC converter
Stop
Normal operation
(Stop when all LED
CH stop)
Normal operation
*1
Stop
Action when protection function is detected
LED driver
Soft-start
FAIL terminal
Stop
Stop after CP charge
(Latch operation)
Stop after CP charge
(Latch operation)
Stop
Discharge
Normal operation
Normal operation
Discharge
OPEN
DRAIN after the CP
charge is completed.
(Latch operation)
DRAIN after the CP
charge is completed.
(Latch operation)
GND
OVP
Stop N output
Normal operation
Normal operation
SCP
Stop N output
Stop after CP charge
(Latch operation)
Discharge after latch
OCP
Stop the N output
(Pulse by Pulse)
Normal operation
Normal operation
（*1）Short protection doesn't hang when becoming remainder 1ch. DCDC output falls as LED short.
OPEN
DRAIN after the CP
charge is completed.
(Latch operation)
OPEN
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TSZ22111・15・001
13/25
TSZ02201-0F1F0C100210-1-2
31.May.2013 Rev.003