18-Bit, 2.5 LSB INL, 800 kSPS SAR ADC
AD7674
FEATURES
FUNCTIONAL BLOCK DIAGRAM
PDBUF
REF
REFGND
DVDD DGND
18-bit resolution with no missing codes
No pipeline delay (SAR architecture)
Differential input range: ±±REF (±REF up to 5 ±)
AGND
AVDD
OVDD
OGND
AD7674
SERIAL
PORT
REFBUFIN
Throughput:
800 kSPS (Warp mode)
18
666 kSPS (Normal mode)
570 kSPS (Impulse mode)
IN+
IN–
SWITCHED
CAP DAC
D[17:0]
BUSY
INL: ±2.5 LSB max (±9.5 ppm of full scale)
Dynamic range : 103 dB typ (±REF = 5 ±)
S/(N+D): 100 dB typ @ 2 kHz (±REF = 5 ±)
Parallel (18-,16-, or 8-bit bus) and serial 5 ±/3 ± interface
SPI®/QSPI™/MICROWIRE™/DSP compatible
On-board reference buffer
PARALLEL
INTERFACE
RD
CS
CLOCK
PD
CONTROL LOGIC AND
CALIBRATION CIRCUITRY
MODE0
MODE1
RESET
CNVST
IMPULSE
WARP
03083–0–001
Single 5 ± supply operation
Power dissipation:
98 mW typ @ 800 kSPS
Figure 1. Functional Block Diagram
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
Table 1. PulSARTM Selection
800–
1000
Type/kSPS
100–250
500–570
Pseudo-
AD7651
AD7650/AD7652 AD7653
APPLICATIONS
Differential
AD7660/AD7661 AD7664/AD7666 AD7667
True Bipolar
AD7663
AD7675
AD7665
AD7676
AD7671
AD7677
CT scanners
True
Differential
High dynamic data acquisition
Geophone and hydrophone sensors
Σ-Δ replacement (low power, multichannel)
Instrumentation
18-Bit
AD7678
AD7679
AD7674
Multichannel/
Simultaneous
AD7654
AD7655
Spectrum analysis
Medical instruments
GENERAL DESCRIPTION
PRODUCT HIGHLIGHTS
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.
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.
The part is available in 48-lead LQFP or 48-lead LFCSP
packages with operation specified from –40°C to +85°C.
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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