MAX873/MAX875/MAX876
Low-Power, Low-Drift, +2.5V/+5V/+10V
Precision Voltage References
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Detailed Description
The MAX873/MAX875/MAX876 precision voltage refer-
ences provide accurate preset +2.5V, +5.0V, and +10V
reference voltages from up to +40V input voltages. These
devices feature a proprietary temperature-coefficient
curvature-correction circuit and laser-trimmed thin-film
resistors that result in a very low 3ppm/°C temperature
coefficient and excellent 0.05% initial accuracy. The
MAX873/MAX875/MAX876 draw 340µA of supply current
and source 30mA or sink 2mA of load current.
Trimming the Output Voltage
Trim the factory-preset output voltage on the
MAX873/MAX875/MAX876 by placing a resistive divider
network between OUT, TRIM, and GND.
Use the following formula to calculate the change in
output voltage from its preset value:
∆V
OUT
= 2 x (V
TRIM
- V
TRIM (open)
) x k
where:
V
TRIM
= 0V to V
OUT
V
TRIM
(open)
= V
OUT
(nominal) / 2 (typ)
k = ±6% (typ)
For example, use a 50kΩ potentiometer (such as the
MAX5436) between OUT, TRIM, and GND with the
potentiometer wiper connected to TRIM (see Figure 2).
As the TRIM voltage changes from V
OUT
to GND, the
output voltage changes accordingly. Set R2 to 1MΩ or
less. Currents through resistors R1 and R2 add to the
quiescent supply current.
Typical Operating Characteristics (continued)
(V
IN
= +5V for V
OUT
= +2.5V, V
IN
= +15V for V
OUT
= +10V, I
OUT
= 0, T
A
= +25°C, unless otherwise noted.)
Temperature Proportional Output Voltage. TEMP generates an output voltage proportional to the die
temperature.
Output Voltage Trim. Connect TRIM to the center of a voltage-divider between OUT and GND for
trimming. Leave unconnected to use the preset output voltage.
