iru431al International Rectifier Corp., iru431al Datasheet - Page 3

• Manufacturer Part Number: iru431al
• Description: Low -voltage Adjustable Precision Shunt Regulator -
• Manufacturer: International Rectifier Corp.

Note 2: The dynamic impedance when V
fined as:
PIN DESCRIPTIONS
BLOCK DIAGRAM
Rev. 1.8
02/20/02
SOT-23
5-PIN
PIN#
1, 2
4
3
5
Z
KA0
=
SOT-23
3-PIN
PIN#
V
NA
I
1
2
3
K
KA
Ref
PIN SYMBOL
1.24V
Cathode
Anode
Ref
NC
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 F 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.
KA
PIN DESCRIPTION
=V
REF
is de-
www.irf.com
When the device is operating with two external resistors
(See figure 3), the total dynamic impedance of the cir-
cuit is given by:
Z
KA
=
Cathode
Anode
V
I
IRU431L / IRU431AL
= Z
KA0
o o 1 +
R1
R2
p p
3