AD7674_15 Datasheet, PDF (1/28 Pages) Analog Devices – 18-Bit, 2.5 LSB INL, 800 kSPS SAR ADC

18-Bit, 2.5 LSB INL, 800 kSPS SAR ADC
AD7674
FEATURES
18-bit resolution with no missing codes
No pipeline delay (SAR architecture)
Differential input range: ±VREF (VREF up to 5 V)
Throughput: 800 kSPS (Warp mode)
666 kSPS (Normal mode)
570 kSPS (Impulse mode)
INL: ±2.5 LSB max (±9.5 ppm of full scale)
Dynamic range : 103 dB typ (VREF = 5 V)
S/(N+D): 100 dB typ @ 2 kHz (VREF = 5 V)
Parallel (18-,16-, or 8-bit bus) and serial 5 V/3 V interface
SPI®/QSPI™/MICROWIRE™/DSP compatible
On-board reference buffer
Single 5 V supply operation
Power dissipation:
98 mW typ @ 800 kSPS
78 mW typ@ 500 kSPS (Impulse mode)
160 μW @ 1 kSPS (Impulse mode)
48-lead LQFP or 48-lead LFCSP package
Pin-to-pin compatible upgrade of AD7676/AD7678/AD7679
APPLICATIONS
CT scanners
High dynamic data acquisition
Geophone and hydrophone sensors
Σ-Δ replacement (low power, multichannel)
Instrumentation
Spectrum analysis
Medical instruments
GENERAL DESCRIPTION
The AD7674 is an 18-bit, 800 kSPS, charge redistribution SAR,
fully differential analog-to-digital converter that operates on a
single 5 V power supply. The part contains a high speed 18-bit
sampling ADC, an internal conversion clock, an internal
reference buffer, error correction circuits, and both serial and
parallel system interface ports.
The part is available in 48-lead LQFP or 48-lead LFCSP
packages with operation specified from –40°C to +85°C.
FUNCTIONAL BLOCK DIAGRAM
PDBUF REF REFGND
DVDD DGND
AGND
AVDD
REFBUFIN
AD7674
SERIAL
PORT
OVDD
OGND
IN+
IN–
PD
RESET
SWITCHED
CAP DAC
CLOCK
CONTROL LOGIC AND
CALIBRATION CIRCUITRY
18
PARALLEL
INTERFACE
D[17:0]
BUSY
RD
CS
MODE0
MODE1
WARP IMPULSE CNVST
Figure 1. Functional Block Diagram
03083–0–001
Table 1. PulSAR^TM Selection
Type/kSPS
Pseudo-
Differential
True Bipolar
True
Differential
18-Bit
Multichannel/
Simultaneous
100–250
AD7651
AD7660/AD7661
AD7663
AD7675
AD7678
500–570
AD7650/AD7652
AD7664/AD7666
AD7665
AD7676
AD7679
AD7654
AD7655
800–
1000
AD7653
AD7667
AD7671
AD7677
AD7674
PRODUCT HIGHLIGHTS
1. High Resolution, Fast Throughput.
The AD7674 is an 800 kSPS, charge redistribution, 18-bit
SAR ADC (no latency).
2. Excellent Accuracy.
The AD7674 has a maximum integral nonlinearity of
2.5 LSB with no missing 18-bit codes.
3. Serial or Parallel Interface.
Versatile parallel (18-, 16- or 8-bit bus) or 3-wire serial
interface arrangement compatible with both 3 V and
5 V logic.
Rev. A
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