BD9422EFV_15 Datasheet, PDF (21/30 Pages) Rohm – White LED Driver for large LCD panel

BD9422EFV
Datasheet
●3.8.2 Protective operation state transition table at FAIL_MODE=L
(Open detection)
before CP charge
PWM
Error state
L(no pulse) or
pulse less than don't care
4cnt.
Not detect
→
discharge
discharge
CP charge
PWM
Error state
→
-
-
-
-
Not detect discharge
pulse over 4cnt.
detect
L(no pulse)
detect
charge
start
charge
Not detect discharge
H(input pulse)
detect
charge
CP=2V arrival
PWM
Error state
end of state
-
-
normal state
-
-
L(no pulse)
H(input pulse)
-
L(no pulse)
H(input pulse)
-
-
Not detect
detect
Not detect
detect
-
Not detect
detect
Not detect
detect
normal state
normal state
normal state
CH latch
FAIL latch
normal state
CH latch
FAIL latch
normal state
normal state
CH latch
FAIL latch
normal state
CH latch
FAIL latch
(Short detection)
before CP charge
PWM
Error state
→
CP charge
PWM
Error state
→
L(no pulse) or
puse less than don't care discharge
-
-
4cnt.
Not detect discharge
-
-
pulse over 4cnt.
detect
L(no pulse)
don't care charge
start
charge
H(input pulse)
Not detect discharge
detect
charge
CP=2V arrival
PWM
Error state
end of state
-
-
normal state
-
L(no pulse)
H(input pulse)
-
L(no pulse)
H(input pulse)
-
don't care
Not deetect
detect
-
don't care
Not deetect
detect
normal state
CH latch
FAIL latch
normal state
CH latch
FAIL latch
normal state
CH latch
FAIL latch
normal state
CH latch
FAIL latch
With "the pulse of less than 4 cnt", it is defined as the pulse width from (100n)sec to (Hi time of less than 4 cnt of DCDC frequency). In the pulse below (100n)sec,
since delay from a PWM pin input to internal logic exists, it becomes unfixed.
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TSZ02201-0F1F0C100210-1-2
1.Sep.2015 Rev.006