BD92111F Datasheet, PDF (13/28 Pages) Rohm – PFC Direct current resonance type White LED Driver for Large LCD

BD92111F
PIN.9 CP
This pin sets up the time from the point of abnormal detection till shut down (Timer Latch). Having 1µA constant
current charges at external capacitor connected to CP pin, it will shut down when it becomes over 2.0V. During soft
start, there is no charge to CP external capacitor even fulfilling CP pin charge condition (timer latch). External
capacitor is set around 0.01µF to 2.2µF).
T_CP
C_CP

V_CP
I_CP

C_CP  2.0
1.0 10^6
 2.0 10⁶  C_CP
[sec]
1uA
Timer Latch Time TCP
100
CCP
10
Timer latch
Shut-down
1
2.0V
0.1
Timer Start
0.01
Figure. 19 CP Block Diagram
0.001
0.001
0.01
0.1
1
10
CP Capacitance CCP[µF]
Figure. 20 Timer Latch Time vs CP Capacitance
PIN.10 PWMIN
By inputting PWM pulse signal at PWMIN pin, it is possible to adjust burst brightness. (High level: over 2.0V, Low
level: below 0.8V).
condition
PWMIN : 2.0V to 5.0V
PWMIN : -0.3V to 0.8V
LED condition
Turn On
Turn Off
PIN.11 SDON
This is for the set up of time till COMPSD starts operation when start up. After STB starts to become ON, there will
be 1µA constant current charging at external capacitor that is connected to SDON pin. Then if it becomes over
2.0V, it is possible to detect COMPSD. When it is below 2.0V, immediately latch protection current will no operate.
External capacitor is around 0.01µF to 2.2µF.
1uA
Csdon
2.0V
Power On
COMPSD
Enable to detect
Figure. 21 IS SDON block diagram
T_SDON
C_SDON

V_SDON
I _SDON

C_SDON  2.0
1.0 10 ^6
 2.010⁶  C_SDON
[sec]
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TSZ02201-0F5F0C100090-1-2
31.Jan.2016 Rev.001