Absolute Maximum Ratings

Input Voltage...........................................................6.0V

SW Voltage..............................................................38V

FB Voltage ..............................................................6.0V

EN ..........................................................................6.0V

OVP Voltage ............................................................38V

Operating Temperature Range .............

-40°Cto+85°C

Storage Temperature Range ..............

-55°C to +150°C

Maximum Junction Temperature........................+150

°C

Note: These are stress ratings only. Stresses exceeding the range specified under

²Absolute Maximum Ratings² may

cause substantial damage to the device. Functional operation of this device at other conditions beyond those listed

in the specification is not implied and prolonged exposure to extreme conditions may affect device reliability.

Electrical Characteristics

mH; Ta=25°C (Unless otherwise specified)

Symbol

Parameter

Test Conditions

Min.

Typ.

Max.

Unit

Input Voltage

¾

2.6

¾

5.5

V

UVLO

Under Voltage Lockout

¾¾

2.4

2.5

V

Supply Current

Switching

¾

1.0

2.5

mA

¾

0.1

1.0

mA

Error Amplifier

Feedback Voltage

¾

190

200

210

mV

Power Switch

Switching Frequency

Measurement at SW pin

0.8

1.2

1.6

MHz

DC

Maximum Duty Cycle

85

90

¾

%

SW On Resistance

¾¾

0.5

¾W

Switch Leakage Current

¾¾

0.1

1.0

mA

EN Pin

EN Voltage High

2.0

¾¾

V

EN Voltage Low

¾¾

0.8

V

OVP and OCP

OVP Threshold

No load

29

32

35

V

N-channel MOSFET Current Limit

¾¾

950

¾

mA

Thermal Shutdown

Thermal Shutdown Threshold

¾¾

150

¾°C

Thermal shutdown Hysteresis

¾¾

15

¾°C

HT7939

Rev 1.10

3

November 3, 2009