High-Precision Voltage References with
Temperature Sensor
MAX6173鈥揗AX6177
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擄C, unless otherwise noted.)
TURN-ON TRANSIENT
(V
OUT
= 10V, C
OUT
= 0)
MAX6173 toc39
TURN-ON TRANSIENT
(V
OUT
= 10V, C
OUT
= 1碌F)
MAX6173 toc40
V
IN
5V/div
GND
V
IN
5V/div
GND
V
OUT
5V/div
GND
100碌s/div
200碌s/div
V
OUT
5V/div
GND
Pin Description
PIN
1, 8
2
3
4
5
6
7
NAME
I.C.
IN
TEMP
GND
TRIM
OUT
N.C.
FUNCTION
Internally Connected. Do not connect externally.
Positive Power-Supply Input
Temperature Proportional Output Voltage. TEMP generates an output voltage proportional to the die
temperature.
Ground
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.
Output Voltage
No Connection. Not internally connected.
Detailed Description
The MAX6173鈥揗AX6177 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/擄C tem-
perature coefficient and excellent 0.05% initial accuracy.
The MAX6173鈥揗AX6177 draw 340碌A(chǔ) of supply current
and source 30mA or sink 2mA of load current.
Use the following formula to calculate the change in
output voltage from its preset value:
鈭哣
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 =
鹵6%
(typ)
For example, use a 50k鈩?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 1M鈩?or
less. Currents through resistors R1 and R2 add to the
quiescent supply current.
Trimming the Output Voltage
Trim the factory-preset output voltage on the
MAX6173鈥揗AX6177 by placing a resistive divider net-
work between OUT, TRIM, and GND.
12
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