LM4040B ZETEX [Zetex Semiconductors], LM4040B Datasheet - Page 10

• Manufacturer Part Number: LM4040B
• Description: Precision micropower shunt voltage references
• Manufacturer: ZETEX [Zetex Semiconductors]

Application information
Printed circuit board layout considerations
LM4040s in the SOT23 package have the die attached to pin 1, which results in an electrical
contact between pin 2 and pin 3. Therefore, pin 1 of the SOT-23 package must be left floating or
connected to pin 2.
LM4040s in the SC75 package have the die attached to pin 2, which results in an electrical contact
between pin 2 and pin 1. Therefore, pin 2 must be left floating or connected to pin1.
Issue 4 - July 2008
© Diodes Incorporated 2008
R
S
I
R
V
S
I
I
R
L
I
+
L
V
R
In a conventional shunt regulator application, an external series resistor (R
connected between the supply voltage, V
R
Since load current and supply voltage may vary, R
supply at least the minimum acceptable I
voltage is at its minimum and the load current is at its maximum value. When
the supply voltage is at its maximum and I
large enough so that the current flowing through the LM4040 is less than 15 mA.
R
and I
R
S
S
S
is determined by the supply voltage, (V
determines the current that flows through the load (I
=
R
V
), and the LM4040’s reverse breakdown voltage, V
I
S
L
+
−
I
V
R
R
10
R
S
S
, and the LM4040
to the LM4040 even when the supply
), the load and operating current, (I
L
is at its minimum, R
S
should be small enough to
R
L
) and the LM4040 (I
.
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www.zetex.com
S
should be
S
) is
R
).
L