
SC4540
Electrical Characteristics (continued)
Parameter
Symbol
Conditions
Min
Typ
Max
Units
Boost Converter Characteristics (continued)
Switch Over-Current Protection
I OCP
425
725
mA
Switch Leakage Current
Switch Saturation Voltage
I L(LX)
V SAT
V LX = 12V
I LX = 0.3A
0.01
250
1
450
μA
mV
COMP Sourcing Current
COMP Sinking Current
I COMP
V COMP = 0.9V, T A = 25oC
V COMP = 0.9V, T A = 25oC
5
6
μA
OUT Over-Voltage Protection
OUT Internal Pull-Down Current
V OVP
I OVP
During OVP condition
38
1
43
V
mA
OUT Bias Current
V EN = V IN , V OUT = 20V
50
70
μA
I OUT
OUT Leakage Current
V EN = 0V, V OUT = V IN = 12V
0.01
1
μA
PWM Dimming Frequency Range (1)(2)
PWM Dimming Duty Cycle Range (1)(2)
f EN
D EN
Applied to EN pin
200Hz on EN pin
100
0
50k
100
Hz
%
Current Sink Characteristics
BL Current Setting Range (3)
1
30
mA
I BL
BL Current Setting Accuracy
T A = 25°C
-3.5
3.5
%
BL Leakage Current
BL Current Line Regulation
BL Voltage
ISET Bias Voltage
ISET-to-I BL Gain
Start-Up Time
I L(BL)
ΔI BL /ΔV IN
V BL
V ISET
A ISET
t start-up
V EN = 0V, V BL = 2V
V IN = 3.0 to 5.5V
0.01
±0.05
0.35
0.5
230
1
0.1
μA
mA/V
V
V
A/A
μs
Notes:
(1) Guaranteed by design.
(2) See PWM Dimming description in the Applications Information section for limitations at high PWM dimming frequencies and low PWM
dimming duty cycles.
(3) Not recommended to program below 1mA with R ISET due to tolerance stackup. To produce output current less than 1mA, set the current >
1mA and use PWM dimming.
4