CAT4237

Doc. No. MD-5013, Rev. B

2

© Catalyst Semiconductor, Inc.

Characteristics subject to change without notice

ABSOLUTE MAXIMUM RATINGS

Parameters

Ratings

Units

-0.3 to +7

V

SHDN

¯¯¯¯¯ voltage

-0.3 to +7

V

SW voltage

-0.3 to 55

V

Storage Temperature Range

-65 to +160

ºC

Junction Temperature Range

-40 to +150

ºC

Lead Temperature

300

ºC

RECOMMENDED OPERATING CONDITIONS

Typical application circuit with external components are shown on page 1.

Parameters

Range

Units

2.8 to 5.5

V

SW pin voltage

0 to 30

V

Ambient Temperature Range

-40 to +85

ºC

6, 7 or 8 LEDs

1 to 40

mA

Note:

(1) Thin SOT23-5 package thermal resistance

DC ELECTRICAL CHARACTERISTICS

Symbol

Parameter

Conditions

Min

Typ

Max

Unit

Operating Current

0.6

0.1

1.5

0.6

mA

Shutdown Current

0.1

1

µA

FB Pin Voltage

285

300

315

mV

FB pin input leakage

1

µA

Programmed LED Current

R1 = 10Ω

R1 = 15Ω

R1 = 20Ω

28.5

19

14.25

30

20

15

31.5

21

15.75

mA

SHDN

¯¯¯¯¯ Logic High

SHDN

¯¯¯¯¯ Logic Low

Enable Threshold Level

Shutdown Threshold Level

0.4

0.8

0.7

1.5

V

V

Switching Frequency

0.8

1.0

1.3

MHz

Switch Current Limit

350

450

600

mA

Switch “On” Resistance

1.0

2.0

Ω

Switch Leakage Current

1

5

µA

Thermal Shutdown

150

ºC

Thermal Hysteresis

20

ºC

Undervoltage Lockout

(UVLO) Threshold

1.9

V

Overvoltage Threshold

35

V