L6902D

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DESCRIPTION (Continued)

Other protections beside thermal shutdown complete the device for a safe and reliable application: overvoltage

protection, frequency folback overcurrent protection and protection vs. feedback disconnection.

The internal fixed switching frequency of 250KHz, and the SO-8 package pin allow to built an ultra compact DC/

DC converter with a minimum board space.

PIN CONNECTION

PIN DESCRIPTION

THERMAL DATA

(*) Package mounted on board.

ABSOLUTE MAXIMUM RATINGS

N°

Pin

Function

1

OUT

Regular Output

2

CS+

Current Error Amplifier input (current sense at higher voltage)

3

CS-

Current Error Amplifier input (current sense at lower voltage)

4

COMP

E/A output to be used for frequency compensation

5

FB

Stepdown feedback input. Connecting directly to this pin results in an output voltage of 1.235V.

An external resistive divider is required for higher output voltages. In this case:

3.3V VREF. No cap is need for stability.

7

GND

Ground

8

VCC

Unregulated DC input voltage.

Symbol

Parameter

Value

Unit

Thermal Resistance Junction to Ambient Max.

110 (*)

°C/W

Symbol

Parameter

Value

Unit

Input Voltage

40

V

Output DC voltageOutput peak voltage at t = 0.1

µs

-1 to 40

-5 to 40

V

V

Maximum output current

Internally limited

Analog pins

4

V

Analog pins

V

0.7

W

Tj

Operating junction temperature range

-40 to 150

°C

Storage temperature range

-55 to 150

°C

8

6

4

7

3

2

5

1

OUT

CS+

CS-

COMP

VCC

GND

VREF

FB

V

out

V

FB

1

R1

R2

--------

+





⋅

1.235V 1

R1

R2

--------

+





==