LM4040DIM3X-5.0 National Semiconductor, LM4040DIM3X-5.0 Datasheet - Page 25

• Manufacturer Part Number: LM4040DIM3X-5.0
• Description: IC,VOLT REFERENCE,FIXED,5V,BIPOLAR,TO-236,3PIN,PLASTIC
• Manufacturer: National Semiconductor

Specifications of LM4040DIM3X-5.0

• Rohs Compliant: NO

Applications Information
The LM4040 is a precision micro-power curvature-corrected
bandgap shunt voltage reference. For space critical applica-
tions, the LM4040 is available in the sub-miniature SOT-23
and SC70 surface-mount package. The LM4040 has been
designed for stable operation without the need of an external
capacitor connected between the “+” pin and the “−” pin. If,
however, a bypass capacitor is used, the LM4040 remains
stable. Reducing design effort is the availability of several
fixed reverse breakdown voltages: 2.048V, 2.500V, 3.000V,
4.096V, 5.000V, 6.000, 8.192V, and 10.000V. The minimum
operating current increases from 60 µA for the LM4040-
2.048 and LM4040-2.5 to 100 µA for the LM4040-10.0. All
versions have a maximum operating current of 15 mA.
LM4040s in the SOT-23 packages have a parasitic Schottky
diode between pin 2 (−) and pin 3 (Die attach interface
contact). Therefore, pin 3 of the SOT-23 package must be
left floating or connected to pin 2.
LM4040s in the SC70 have a parasitic Schottky diode be-
tween pin 1 (−) and pin 2 (Die attach interface contact).
Therefore, pin 2 must be left floating or connected to pin1.
The 4.096V version allows single +5V 12-bit ADCs or DACs
to operate with an LSB equal to 1 mV. For 12-bit ADCs or
DACs that operate on supplies of 10V or greater, the 8.192V
version gives 2 mV per LSB.
The typical thermal hysteresis specification is defined as the
change in +25˚C voltage measured after thermal cycling.
Typical Applications
FIGURE 1. Shunt Regulator
25
The device is thermal cycled to temperature -40˚C and then
measured at 25˚C. Next the device is thermal cycled to
temperature +125˚C and again measured at 25˚C. The re-
sulting V
thermal hysteresis. Thermal hysteresis is common in preci-
sion references and is induced by thermal-mechanical pack-
age stress. Changes in environmental storage temperature,
operating temperature and board mounting temperature are
all factors that can contribute to thermal hysteresis.
In a conventional shunt regulator application (Figure 1) , an
external series resistor (R
ply voltage and the LM4040. R
flows through the load (I
current and supply voltage may vary, R
enough to supply at least the minimum acceptable I
LM4040 even when the supply voltage is at its minimum and
the load current is at its maximum value. When the supply
voltage is at its maximum and I
be large enough so that the current flowing through the
LM4040 is less than 15 mA.
R
operating current, (I
breakdown voltage, V
01132315
S
is determined by the supply voltage, (V
OUT
delta shift between the 25˚C measurements is
L
R
and I
.
L
) and the LM4040 (I
S
) is connected between the sup-
Q
), and the LM4040’s reverse
L
S
is at its minimum, R
determines the current that
S
should be small
S
), the load and
Q
). Since load
www.national.com
S
Q
should
to the