REF102_15 Datasheet, PDF (6/20 Pages) Texas Instruments – 10V Precision Voltage Reference

INSTALLATION AND
OPERATING INSTRUCTIONS
BASIC CIRCUIT CONNECTION
Figure 2 shows the proper connection of the REF102. To
achieve the specified performance, pay careful attention to
layout. A low resistance star configuration will reduce voltage
errors, noise pickup, and noise coupled from the power
supply. Commons should be connected as indicated, being
sure to minimize interconnection resistances.
(1)
2
(2)
V+
6
+ _1µF
Tantalum
REF102
R_{L 1}
R_{L 2}
R_{L 3}
4
(1)
(2)
NOTES: (1) Lead resistances here of up to a few ohms have
negligible effect on performance. (2) A resistance of 0.1Ω in
series with these leads will cause a 1mV error when the load
current is at its maximum of 10mA. This results in a 0.01%
error of 10V.
FIGURE 2. REF102 Installation.
OPTIONAL OUTPUT VOLTAGE ADJUSTMENT
Optional output voltage adjustment circuits are shown in
Figures 3 and 4. Trimming the output voltage will change the
voltage drift by approximately 0.008ppm/°C per mV of trimmed
voltage. In the circuit in Figure 3, any mismatch in TCR
between the two sections of the potentiometer will also affect
drift, but the effect of the ∆TCR is reduced by a factor of five
by the internal resistor divider. A high quality potentiometer,
with good mechanical stability, such as a cermet, should be
used. The circuit in Figure 3 has a minimum trim range of
±300mV. The circuit in Figure 4 has less range but provides
higher resolution. The mismatch in TCR between R_S and the
internal resistors can introduce some slight drift. This effect
is minimized if R_S is kept significantly larger than the 50kΩ
internal resistor. A TCR of 100ppm/°C is normally sufficient.
V+
2
REF102
V_OUT
6
V_TRIM
5
4
+ _1µF
Tantalum
20k Ω
Output
Voltage
Adjust
+10V
Minimum range (±300mV) and minimal
degradation of drift.
FIGURE 3. REF102 Optional Output Voltage Adjust.
V+
2
V_OUT
6
REF102
V_TRIM
5
R_S
1M Ω
4
+ _1µF
Tantalum
20k Ω
Output
Voltage
Adjust
+10V
Higher resolution, reduced range (typically ±25mV).
FIGURE 4. REF102 Optional Output Voltage, Fine Adjust.
6
REF102
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