AD7171 Datasheet, PDF (1/16 Pages) Analog Devices – 16-Bit Low Power Sigma-Delta ADC

FEATURES
Output data rate: 125 Hz
Pin-programmable power-down and reset
Status function
Internal clock oscillator
Current: 135 μA
Power supply: 2.7 V to 5.25 V
–40°C to +105°C temperature range
Package: 10-lead 3 mm x 3 mm LFCSP
INTERFACE
2-wire serial (read-only device)
SPI compatible
Schmitt trigger on SCLK
APPLICATIONS
Weigh scales
Pressure measurement
Industrial process control
Portable instrumentation
16-Bit Low Power Sigma-Delta ADC
AD7171
FUNCTIONAL BLOCK DIAGRAM
GND V_DD
REFIN(+) REFIN(–)
AIN(+)
AIN(–)
16-BIT Σ-Δ
ADC
DOUT/RDY
SCLK
AD7171
INTERNAL
CLOCK
PDRST
Table 1.
VREF = VDD
5V
3V
RMS Noise
11.5 μV
6.9 μV
Figure 1.
P-P Noise
76 μV
45 μV
P-P
Resolution
16 bits
16 bits
ENOB
16 bits
16 bits
GENERAL DESCRIPTION
The AD7171 is a very low power 16-bit analog-to-digital converter
(ADC). It contains a precision 16-bit sigma-delta (Σ-Δ) ADC
and an on-chip oscillator. Consuming only 135 μA, the AD7171
is particularly suitable for portable or battery operated products
where very low power is a requirement. The AD7171 also has a
power-down mode in which the device consumes 5 μA, thus
increasing the battery life of the product.
For ease-of-use, all the features of the AD7171 are controlled by
dedicated pins. Each time a data read occurs, eight status bits
are appended to the 16-bit conversion. These status bits contain
a pattern sequence that can be used to confirm the validity of
the serial transfer.
The output data rate of the AD7171 is 125 Hz, whereas the
settling time is 24 ms. The AD7171 has one differential input
and a gain of 1. This is useful in applications where the user
needs to use an external amplifier to implement system-specific
filtering or gain requirements.
The AD7171 operates with a power supply from 2.7 V to 5.25 V.
It is available in a 10-lead LFCSP package.
The AD7170 is a 12-bit version of the AD7171. It has the same
feature set as the AD7171 and is pin-for-pin compatible.
Rev. 0
Information furnished by Analog Devices is believed to be accurate and reliable. However, no
responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other
rights of third parties that may result from its use. Specifications subject to change without notice. No
license is granted by implication or otherwise under any patent or patent rights of Analog Devices.
Trademarks and registered trademarks are the property of their respective owners.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: [phone]
www.analog.com
Fax: [phone]
©2009 Analog Devices, Inc. All rights reserved.