IRU431L / IRU431AL

3

Rev. 1.8

02/20/02

www.irf.com

PIN DESCRIPTIONS

BLOCK DIAGRAM

Figure 2 - Simplified block diagram of the IRU431L.

Resistors from the Ref pin to the Cathode pin and to ground form a divider

that sets the output voltage.

The output of the shunt regulator. A capacitor of 1

mF minimum value must

be connected from this pin to Anode pin to insure unconditional stability.

Ground pin. This pin must be connected to the lowest potential in the

system and all other pins must be at higher potential with respect to this

pin.

These pins are not connected internally.

fined as:

Cathode

1.24V

Anode

Ref

+

When the device is operating with two external resistors

(See figure 3), the total dynamic impedance of the cir-

cuit is given by:

SOT-23

5-PIN

PIN#

SOT-23

3-PIN

PIN#

PIN SYMBOL

PIN DESCRIPTION

4

3

5

1, 2

1

2

3

NA

Ref

Cathode

Anode

NC

=

oo1 + pp

R1

R2

DV

DI