AD7634BSTZ Datasheet, PDF (1/32 Pages) Analog Devices – 18-Bit, 670 kSPS, Differential Programmable Input PulSAR® ADC

Data Sheet
18-Bit, 670 kSPS, Differential
Programmable Input PulSAR^® ADC
AD7634
FEATURES
Multiple pins/software-programmable input ranges
5 V (10 V p-p), +10 V (20 V p-p), ±5 V (20 V p-p),
±10 V (40 V p-p)
Pins or serial SPI®-compatible input ranges/mode selection
Throughput
670 kSPS (warp mode)
570 kSPS (normal mode)
450 kSPS (impulse mode)
INL: ±1.5 LSB typical, ±2.5 LSB maximum (±9.5 ppm of FSR)
18-bit resolution with no missing codes
Dynamic range: 102.5 dB
SNR: 101 dB @ 2 kHz
THD: −112 dB @ 2kHz
iCMOS® process technology
5 V internal reference: typical drift 3 ppm/°C; TEMP output
No pipeline delay (SAR architecture)
Parallel (18-/16-/8-bit bus) and serial 5 V/3.3 V interface
SPI-/QSPI™-/MICROWIRE™-/DSP-compatible
Power dissipation
180 mW @ 670 kSPS, warp mode
28 mW @ 100 kSPS, impulse mode
10 mW @ 1 kSPS, impulse mode
Pb-free, 48-lead LQFP and 48-Lead LFCSP (7 mm × 7 mm)
APPLICATIONS
CT scanners
High dynamic data acquisition
Σ-Δ replacement
Spectrum analysis
Medical instruments
Instrumentation
Process controls
GENERAL DESCRIPTION
The AD7634 is an 18-bit charge redistribution successive
approximation register (SAR), architecture analog-to-
digital converter (ADC) fabricated on Analog Devices, Inc.’s
iCMOS high voltage process. The device is configured through
hardware or via a dedicated write-only serial configuration port
for input range and operating mode. The AD7634 contains a
high speed 18-bit sampling ADC, an internal conversion clock,
an internal reference (and buffer), error correction circuits, and
both serial and parallel system interface ports. A falling edge on
CNVST samples the fully differential analog inputs on IN+ and
IN−. The AD7634 features four different analog input ranges and
three different sampling modes. Operation is specified from
−40°C to +85°C.
Rev. B
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FUNCTIONAL BLOCK DIAGRAM
TEMP REFBUFIN REF REFGND VCC VEE DVDD DGND
AGND
AVDD
PDREF
PDBUF
IN+
IN–
REF
REF
AMP
SWITCHED
CAP DAC
CNVST
PD
RESET
CLOCK
CONTROL LOGIC AND
CALIBRATION CIRCUITRY
AD7634
SERIAL DATA
PORT
SERIAL
CONFIGURATION
PORT
18
PARALLEL
INTERFACE
OVDD
OGND
D[17:0]
BUSY
RD
CS
D0/OB/2C
D1/A0
D2/A1
WARP IMPULSE BIPOLAR TEN
MODE0
Figure 1.
MODE1
Table 1. 48-Lead PulSAR Selection
Input Type
Res
(Bits)
100 to
250
(kSPS)
500 to
570
(kSPS)
Bipolar
14
Differential
14
Bipolar
Unipolar
16
AD7651 AD7650
AD7660 AD7652
AD7661 AD7664
AD7666
Bipolar
16
AD7610 AD7665
AD7663
Differential
Unipolar
16
AD7675 AD7676
570 to
1000
(kSPS)
AD7951
AD7952
AD7653
AD7667
AD7612
AD7671
AD7677
Simultaneous/ 16
Multichannel
Unipolar
AD7654
AD7655
Differential
Unipolar
18
AD7678 AD7679 AD7674
Differential
Bipolar
18
AD7631
AD7634
>1000
(kSPS)
AD7621
AD7622
AD7623
AD7641
AD7643
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