Low Noise Micropower 2.5 V and
4.096 V Precision Voltage References
ADR291/ADR292
Rev. F
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FEATURES
Supply range
2.8 V to 15 V, ADR291
4.4 V to 15 V, ADR292
Supply current: 15 μA maximum
Low noise: 8 μV and 12 μV p-p (0.1 Hz to 10 Hz)
High output current: 5 mA
Temperature range: −40°C to +125°C
Pin-compatible with REF02/REF19x
APPLICATIONS
Portable instrumentation
Precision reference for 3 V and 5 V systems
Analog-to-digital and digital-to-analog converter reference
Solar-powered applications
Loop-current-powered instruments
CONNECTION DIAGRAMS
NC 1
V
IN
2
NC 3
GND
4
NC8
NC7
V
OUT
6
NC
5
NC = NO CONNECT
ADR291/
ADR292
TOP VIEW
(Not to Scale)
00163-001
Figure 1. 8-Lead SOIC (R-8)
1
2
3
4
V
IN
NC
GND
NC
8
7
6
5
NC
V
OUT
NC
NC
NC = NO CONNECT
00163-002
ADR291/
ADR292
TOP VIEW
(Not to Scale)
Figure 2. 8-Lead TSSOP (RU-8)
321
V
OUT
GND
V
IN
TOP VIEW
(Not to Scale)
ADR291
00163-003
Figure 3. 3-Lead TO-92 (T-3)
GENERAL DESCRIPTION
The ADR291 and ADR292 are low noise, micropower precision
voltage references that use an XFET® reference circuit. The new
XFET architecture offers significant performance improvements
over traditional band gap and buried Zener-based references.
Improvements include one quarter the voltage noise output of
band gap references operating at the same current, very low and
ultralinear temperature drift, low thermal hysteresis, and
excellent long-term stability.
The ADR291/ADR292 family is a series of voltage references
providing stable and accurate output voltages from supplies as
low as 2.8 V for the ADR291. Output voltage options are 2.5 V
and 4.096 V for the ADR291 and ADR292, respectively.
Quiescent current is only 12 μA, making these devices ideal for
battery-powered instrumentation. Three electrical grades are
available offering initial output accuracies of ±2 mV, ±3 mV,
and ±6 mV maximum for the ADR291, and ±3 mV, ±4 mV,
and ±6 mV maximum for the ADR292. Temperature
coefficients for the three grades are 8 ppm/°C, 15 ppm/°C, and
25 ppm/°C maximum, respectively. Line regulation and load
regulation are typically 30 ppm/V and 30 ppm/mA, maintaining
the reference’s overall high performance. For a device with 5.0 V
output, refer to the ADR293 data sheet.
The ADR291 and ADR292 references are specified over the
extended industrial temperature range of −40°C to +125°C.
Devices are available in the 8-lead SOIC, 8-lead TSSOP, and
3-lead TO-92 packages.
Table 1. ADR291/ADR292 Product
Part No.
Output
Voltage (V)
Initial
Accuracy (±%)
Temperature
Coefficient
(ppm/°C) Max
ADR291 2.500 0.08, 0.12, 0.24 8, 15, 25
ADR292 4.096 0.07, 0.10, 0.15 8, 15, 25
