GENERAL DESCRIP
tiON
The AD79811 is a 16-bit, successive approximation, PulSAR®
analog-to-digital converter (ADC) designed for high
temperature operation. The AD7981 is capable of sample rates of
up to 600 kSPS while maintaining low power consumption from a
single power supply, VDD. It is a fast throughput, high accuracy,
high temperature, successive approximation register (SAR) ADC,
packaged in a small form factor with a versatile serial port
interface (SPI).
On the CNV rising edge, the AD7981 samples an analog input,
IN+, between 0 V and REF with respect to a ground sense, IN−.
The reference voltage, REF, is applied externally and can be set
independent of the supply voltage, VDD. The device power
scales linearly with throughput.
The SPI-compatible serial interface also features the ability,
using the SDI input, to daisy-chain several ADCs on a single,
3-wire bus and provides an optional busy indicator. It is
compatible with 1.8 V, 2.5 V, 3 V, or 5 V logic, using the separate
supply, VIO.
For space constrained applications, the AD7981 is available in a
10-lead mini small outline package (MSOP) with operation specified
from −55°C to +175°C and 10-lead ceramic flat package
(FLATPACK) with operation specified from −55°C to +210°C.
These packages are designed for robustness at extreme
temperatures, including monometallic wire bonding, and are
qualified for up to 1000 hours of operation at the maximum
temperature rating.
FEATURES
Extreme high temperature operation
Specified temperature range
−55°C to +210°C (10-lead FLATPACK)
−55°C to +175°C (10-lead MSOP)
High performance
Pseudo differential analog input range
0 V to VREF with VREF between 2.4 V and 5.1 V
Throughput: 600 kSPS
Zero latency architecture
16-bit resolution with no missing codes
INL: ±2.5 LSB maximum, DNL: ±0.9 LSB maximum
Dynamic range: 92 dB, VREF = 5 V
SNR: 91 dB at fIN = 1 kHz, VREF = 5 V
THD: −102 dB at fIN = 1 kHz, VREF = 5 V
SINAD: 90.5 dB at fIN = 1 kHz, VREF = 5 V
Low power dissipation
Single-supply 2.5 V operation with 1.8 V to 5 V logic
interface
2.25 mW typical at 600 kSPS (VDD only)
4.65 mW typical at 600 kSPS (total)
75 μW typical at 10 kSPS
Proprietary serial interface
SPI-/QSPI-/MICROWIRE-/DSP-compatible
Daisy-chain multiple ADCs and busy indicator
Small footprint
10-lead, 3 mm × 3 mm, monometallic wire bonding MSOP
10-lead, 0.255 inches × 0.255 inches, monometallic wire
bonding FLATPACK
APPLICATIONS
Oil and gas exploration
Avionics
Heavy industrial
High temperature environments
Scientific instrumentation
