ADR1581 Analog Devices, Inc., ADR1581 Datasheet - Page 7

• Manufacturer Part Number: ADR1581
• Description: 1.25 V Micropower, Precision Shunt Voltage Reference
• Manufacturer: Analog Devices, Inc.

For example, the ADR1581BRT initial tolerance is ±1.5 mV;
a ±50 ppm/°C temperature coefficient corresponds to an error
band of ±4.1 mV (50 × 10
unit is guaranteed to be 1.250 V ± 5.6 mV over the operating
temperature range.
Duplication of these results requires a combination of high
accuracy and stable temperature control in a test system. Evaluation
of the ADR1581 produces curves similar to those in
and Figure 12.
VOLTAGE OUTPUT NONLINEARITY VS.
TEMPERATURE
When a reference is used with data converters, it is important to
understand how temperature drift affects the overall converter
performance. The nonlinearity of the reference output drift
represents additional error that is not easily calibrated out of the
system. The usual way of showing the reference output drift is to
plot the reference voltage vs. temperature (see Figure 12). An
alternative method is to draw a straight line between the
temperature endpoints and measure the deviation of the output
from the straight line. This shows the same data in a different
format. This characteristic (see Figure 13) is generated by
normalizing the measured drift characteristic to the endpoint
average drift. The residual drift error of approximately 500 ppm
shows that the ADR1581 is compatible with systems that require
10-bit accurate temperature performance.
1.2508
1.2506
1.2504
1.2502
1.2500
1.2498
1.2496
1.2494
1.2492
1.2490
1.2488
–55
SLOPE = TC =
Figure 12. Output Voltage vs. Temperature
–35
V
MIN
–15
SLOPE = TC =
(+85°C – +25°C) × 1.250V × 10
−6
5
TEMPERATURE (°C)
× 1.250 V × 65°C). Therefore, the
(V
25
MAX
V
(–40°C – +25°C) × 1.250V × 10
O
– V
45
O
)
(V
65
MIN
V
–6
– V
MAX
85
O
)
105
Figure 4
–6
125
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REVERSE VOLTAGE HYSTERESIS
A major requirement for high performance industrial
equipment manufacturers is a consistent output voltage at
nominal temperature following operation over the operating
temperature range. This characteristic is generated by measuring
the difference between the output voltage at +25°C after operating
at +85°C and the output voltage at +25°C after operating at −40°C.
Figure 14 displays the hysteresis associated with the ADR1581.
This characteristic exists in all references and has been minimized
in the ADR1581.
600
500
400
300
200
100
40
35
30
25
20
15
10
–400
5
0
0
–55
Figure 14. Reverse Voltage Hysteresis Distribution
–300
–35
–15
Figure 13. Residual Drift Error
–200
HYSTERESIS VOLTAGE (µV)
5
–100
TEMPERATURE (°C)
25
0
45
100
65
200
85
300
ADR1581
105
400
125