Datasheet

MAX6173–MAX6177
High-Precision Voltage References with
Temperature Sensor
16
Maxim Integrated
Detailed Description
The MAX6173–MAX6177 precision voltage references
provide accurate preset +2.5V, +3.3V, +4.096V, +5.0V,
and +10V reference voltages from up to +40V input volt-
ages. These devices feature a proprietary temperature-
coefficient curvature-correction circuit and laser-trimmed
thin-film resistors that result in a very low 3ppm/°C tem-
perature coefficient and excellent 0.05% initial accuracy.
The MAX6173–MAX6177 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
MAX6173–MAX6177 by placing a resistive divider net-
work between OUT, TRIM, and GND.
Use the following formula to calculate the change in
output voltage from its preset value:
ΔV
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.
Temp Output
The MAX6173–MAX6177 provide a temperature output
proportional to die temperature. TEMP can be calculated
from the following formula:
TEMP (V) = T
J
(°K) x n
where T
J
= the die temperature,
n = the temperature multiplier,
T
A
= the ambient temperature.
Self-heating affects the die temperature and conversely,
the TEMP output. The TEMP equation assumes the output
is not loaded. If device power dissipation is negligible,
then T
J
≈ T
A
.
n
VatTT
T
mV K
TEMP J
()
.=
=
≅°
0
0
19
PIN NAME FUNCTION
1, 8 I.C. Internally Connected. Do not connect externally.
2 IN Positive Power-Supply Input
3 TEMP
Temperature Proportional Output Voltage. TEMP generates an output voltage proportional to the die
temperature.
4 GND Ground
5 TRIM
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.
6 OUT Output Voltage
7 N.C. No Connection. Not internally connected.
Pin Description