16-Bit, 2 LSB INL, 3 MSPS PulSAR® ADC
AD7621
FEATURES
Throughput
FUNCTIONAL BLOCK DIAGRAM
TEMP REFBUFIN REF REFGND
DVDD DGND
3 MSPS (wideband warp and warp mode)
2 MSPS (normal mode)
1.25 MSPS (impulse mode)
AGND
AVDD
OVDD
OGND
AD7621
REF
REF AMP
SERIAL
PORT
2.048 V internal reference
16
IN+
IN–
SWITCHED
CAP DAC
Differential input range: VREF (VREF up to 2.5 V)
INL: 2 LSB maximum, 1 LSB typical
16-bit resolution with no missing codes
SINAD: 89 dB typical @ 100 kHz
THD: −101 dB typical @ 100 kHz
No pipeline delay (SAR architecture)
Parallel (16- or 8-bit bus) and serial 5 V/3.3 V/2.5 V interface
SPI®-/QSPI™-/MICROWIRE™-/DSP-compatible
2.5 V single-supply operation
D[15:0]
SER/PAR
BUSY
PARALLEL
INTERFACE
PDREF
PDBUF
PD
RD
CLOCK
CS
CONTROL LOGIC AND
CALIBRATION CIRCUITRY
OB/2C
BYTESWAP
RESET
WARP
IMPULSE CNVST
Figure 1.
Power dissipation: 65 mW typical @ 3 MSPS
48-lead LQFP and 48-lead LFCSP_VQ packages
Speed upgrade of the AD7677
Table 1. PulSAR Selection
800 to
100 to 250 500 to 570 1000
AD7651 AD7650/52 AD7653
AD7660/61 AD7664/66 AD7667
Type/kSPS
>1000
Pseudo
Differential
APPLICATIONS
Medical instruments
High speed data acquisition
Digital signal processing
Communications
Instrumentation
True Bipolar
True
Differential
18-Bit
Multichannel/
Simultaneous
AD7663
AD7665
AD7671
AD7675
AD7678
AD7676
AD7679
AD7677 AD7621
AD7674 AD7641
Spectrum analysis
ATE
AD7654
AD7655
GENERAL DESCRIPTION
PRODUCT HIGHLIGHTS
1. Fast Throughput.
The AD7621 is a 16-bit, 3 MSPS, charge redistribution SAR,
fully differential analog-to-digital converter (ADC) that
operates from a single 2.5 V power supply. It contains a high
speed 16-bit sampling ADC, an internal conversion clock, an
internal reference (and buffer), error correction circuits, and
both serial and parallel system interface ports. It features two
very high sampling rate modes (wideband warp and warp), a
fast mode (normal) for asynchronous rate applications, and a
reduced power mode (impulse) for low power applications
where the power is scaled with the throughput. Operation is
specified from −40°C to +85°C.
The AD7621 is a 3 MSPS, charge redistribution,
16-bit SAR ADC.
2. Superior Linearity.
The AD7621 has no missing 16-bit code.
3. Internal Reference.
The AD7621 has a 2.048 V internal reference with a
typical drift of 7 ppm/°C.
4. Single-Supply Operation.
The AD7621 operates from a 2.5 V single supply and
typically dissipates 65 mW. In impulse mode, its power
dissipation decreases with the throughput.
5. Serial or Parallel Interface.
Versatile parallel (16- or 8-bit bus) or 2-wire serial interface
arrangement compatible with 2.5 V, 3.3 V, or 5 V logic.
Rev. 0
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