4

Electrical Characteristics (continued)

SC4540

Parameter

Symbol

Conditions

Min

Typ

Max

Units

Boost Converter Characteristics (continued)

Switch Over-Current Protection

I

OCP

425

725

mA

Switch Leakage Current

I

L(LX)

V

LX

= 12V

0.01

1

μA

Switch Saturation Voltage

V

SAT

I

LX

= 0.3A

250

450

mV

COMP Sourcing Current

I

COMP

V

COMP

= 0.9V, T

A

= 25ºC

5

μA

COMP Sinking Current

V

COMP

= 0.9V, T

A

= 25ºC

6

OUT Over-Voltage Protection

V

OVP

38

43

V

OUT Internal Pull-Down Current

I

OVP

During OVP condition

1

mA

OUT Bias Current

I

OUT

V

EN

= V

IN

, V

OUT

= 20V

50

70

μA

OUT Leakage Current

V

EN

= 0V, V

OUT

= V

IN

= 12V

0.01

1

μA

f

EN

Applied to EN pin

100

50k

Hz

D

EN

200Hz on EN pin

0

100

%

Current Sink Characteristics

I

BL

130

mA

BL Current Setting Accuracy

T

A

= 25°C

-3.5

3.5

%

BL Leakage Current

I

L(BL)

V

EN

= 0V, V

BL

= 2V

0.01

0.1

μA

BL Current Line Regulation

ΔI

BL

/ΔV

IN

V

IN

= 3.0 to 5.5V

±0.05

mA/V

BL Voltage

V

BL

0.35

V

ISET Bias Voltage

V

ISET

0.5

V

ISET-to-I

BL

Gain

A

ISET

230

A/A

Start-Up Time

t

start-up

1μs

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.