CAT4238

Doc. No. MD-5019 Rev. C

2

© Catalyst Semiconductor, Inc.

Characteristics subject to change without notice

ABSOLUTE MAXIMUM RATINGS

Parameters

Ratings

Units

VIN, FB voltage

-0.3 to +7

V

SHDN

¯¯¯¯¯ voltage

-0.3 to +7

V

SW voltage

(1)

up to 60

V

Storage Temperature Range

-65 to +160

ºC

Junction Temperature Range

-40 to +150

ºC

Lead Temperature

300

ºC

Note:

(1) The SW pin voltage is rated up to 39V for external continuous DC voltage.

RECOMMENDED OPERATING CONDITIONS

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

Parameters

Range

Units

VIN

up to 5.5

V

SW pin voltage

0 to 38

V

Ambient Temperature Range

-40 to +85

ºC

DC ELECTRICAL CHARACTERISTICS

VIN = 3.6V, ambient temperature of 25ºC (over recommended operating conditions unless specified otherwise).

Symbol

Parameter

Test Conditions

Min

Typ

Max

Units

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 = 10

Ω

R1 = 15

Ω

R1 = 20

Ω

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

DC

Maximum Duty Cycle

VIN = 3V

92

%

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 Detection Threshold

40

V

Output Voltage Clamp

“Open LED”

42

V