REV. Pr D
Preliminary Technical Data
PRELIMINARY TECHNICAL DATA
Information furnished by Analog Devices is believed to be accurate and
reliable. However, no responsibility is assumed by Analog Devices for its
use, nor for any infringements of patents or other rights of third parties
which may result from its use. No license is granted by implication or
otherwise under any patent or patent rights of Analog Devices.
a
AD7621
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781/329-4700 www.analog.com
Fax: 781/326-8703 © Analog Devices, Inc., 2003
16-Bit, 1 LSB INL, 3 MSPS PulSAR
TM
ADC
FUNCTIONAL BLOCK DIAGRAM
SWITCHED
CAP DAC
16
CONTROL LOGIC AND
CALIBRATION CIRCUITRY
CLOCK
AD7621
D[15:0]
BUSY
RD
CS
OB/2C
OGND
OVDD
DGNDDVDD
AVDD
AGND
REF REFGND
IN+
IN-
PD
RESET
SERIAL
PORT
PARALLEL
INTERFACE
CNVST
PDBUF
REFBUFIN
WARP IMPULSE
BYTESWAP
PDREF
REF
TEMP
SER/PAR
FEATURES
16 Bits Resolution with No Missing Codes
No Pipeline Delay ( SAR architecture )
Differential Input Range: H11550V
REF
(V
REF
up to 2.5V)
Throughput:
3 MSPS (Wideband Warp and Warp Mode)
2 MSPS (Normal Mode)
1.25 MSPS (Impulse Mode)
INL: H115501 LSB Max (H115500.0015% of Full-Scale)
S/(N+D): 90 dB Typ @ 100 kHz ( V
REF
= 2.5V )
THD: –100 dB Typ @ 100 kHz
Parallel (16 or 8bits bus) and Serial 5V/3.3V/2.5V Interface
SPI/QSPI/MICROWIRE/DSP Compatible
On-board Low Drift Reference with Buffer and Temperature
sensor
Single 2.5 V Supply Operation
Power Dissipation: 100 mW Typ @ 3 MSPS
Power-Down Mode
Package: 48-Lead Quad Flat Pack (LQFP)
48-Lead Frame Chip Scale Package (LFCSP)
Speed Upgrade of the AD7677
APPLICATIONS
Medical Instruments
High Speed Data Acquisition
Communications
Instrumentation
Spectrum Analysis
ATE
GENERAL DESCRIPTION
The AD7621 is a 16-bit, 3 MSPS, charge redistribution
SAR, fully differential analog-to-digital converter that
operates from a single 2.5 V power supply. The part
contains a high-speed 16-bit sampling ADC, an internal
conversion clock, an internal reference buffer, error
correction circuits, and both serial and parallel system
interface ports.
It features a very high sampling rate mode (Wideband
Warp) for undersampling applications and, for asyn-
chronous conversion rate applications, a fast mode
(Normal) and, for low power applications, a reduced
power mode (Impulse) where the power is scaled with
the throughput.
It is available in a 48-lead LQFP or a 48-lead LFCSP
with operation specified from –40°C to +85°C.
PRODUCT HIGHLIGHTS
1. High resolution and Fast Throughput
The AD7621 is a 3 MSPS, charge redistribution,
16-bit SAR ADC ( no latency ).
2. Excellent accuracy
The AD7621 has a maximum integral nonlinearity of 1
LSB with no missing 16-bit code.
3. Single-Supply Operation
The AD7621 operates from a single 2.5 V supply and
typically dissipates only 100 mW. In impulse mode,
its power dissipation decreases with the throughput and
it features a power-down mode.
5. Serial or Parallel Interface
Versatile parallel (16 or 8 bits bus) or 2-wire serial
interface arrangement compatible with either 2.5V,
3.3V or 5 V logic.
Pseudo AD7651 AD7650/52 AD7653
Differential AD7660/61 AD7664/66 AD7667
True Bipolar AD7663 AD7665 AD7671
True AD7675 AD7676 AD7677 AD7621
Differential
18 Bit AD7678 AD7679 AD7674
Multichannel/ AD7654 AD7655
Simultaneous
Type / kSPS 100 - 250 500 - 570 800 - 1000 >1000
PulSAR Selection