EVAL-AD7689EDZ Datasheet, PDF (1/32 Pages) Analog Devices – 16-Bit, 4-Channel/8-Channel, 250 kSPS PulSAR ADC

Data Sheet
FEATURES
16-bit resolution with no missing codes
4-channel (AD7682)/8-channel (AD7689) multiplexer with
choice of inputs
Unipolar single-ended
Differential (GND sense)
Pseudobipolar
Throughput: 250 kSPS
INL: ±0.4 LSB typical, ±1.5 LSB maximum (±23 ppm or FSR)
Dynamic range: 93.8 dB
SINAD: 92.5 dB at 20 kHz
THD: −100 dB at 20 kHz
Analog input range: 0 V to VREF with VREF up to VDD
Multiple reference types
Internal selectable 2.5 V or 4.096 V
External buffered (up to 4.096 V)
External (up to VDD)
Internal temperature sensor (TEMP)
Channel sequencer, selectable 1-pole filter, busy indicator
No pipeline delay, SAR architecture
Single-supply 2.3 V to 5.5 V operation with
1.8 V to 5.5 V logic interface
Serial interface compatible with SPI, MICROWIRE,
QSPI, and DSP
Power dissipation
3.5 mW @ 2.5 V/200 kSPS
12.5 mW @ 5 V/250 kSPS
Standby current: 50 nA
Low cost grade available
20-lead 4 mm × 4 mm LFCSP package
APPLICATIONS
Multichannel system monitoring
Battery-powered equipment
Medical instruments: ECG/EKG
Mobile communications: GPS
Power line monitoring
Data acquisition
Seismic data acquisition systems
Instrumentation
Process control
16-Bit, 4-Channel/8-Channel,
250 kSPS PulSAR ADC
AD7682/AD7689
FUNCTIONAL BLOCK DIAGRAM
0.5V TO VDD – 0.5V 0.5V TO VDD
0.1µF
10µF
2.3V TO 5.5V
REFIN
REF
VDD
BAND GAP
REF
IN0
IN1
IN2
IN3
IN4
IN5
IN6
IN7
COM
TEMP
SENSOR
AD7689
MUX
16-BIT SAR SPI SERIAL
ADC
INTERFACE
ONE-POLE
LPF
SEQUENCER
GND
1.8V
VIO _TO
VDD
CNV
SCK
SDO
DIN
Figure 1.
Table 1. Multichannel 14-/16-Bit PulSAR® ADC
Type
Channels 250 kSPS 500 kSPS ADC Driver
14-Bit 8
AD7949
ADA4841-x
16-Bit 4
AD7682
ADA4841-x
16-Bit 8
AD7689 AD7699 ADA4841-x
GENERAL DESCRIPTION
The AD7682/AD7689 are 4-channel/8-channel, 16-bit, charge
redistribution successive approximation register (SAR) analog-
to-digital converters (ADCs) that operate from a single power
supply, VDD.
The AD7682/AD7689 contain all components for use in a
multichannel, low power data acquisition system, including a
true 16-bit SAR ADC with no missing codes; a 4-channel
(AD7682) or 8-channel (AD7689), low crosstalk multiplexer
that is useful for configuring the inputs as single-ended (with or
without ground sense), differential, or bipolar; an internal low
drift reference (selectable 2.5 V or 4.096 V) and buffer; a
temperature sensor; a selectable one-pole filter; and a sequencer
that is useful when channels are continuously scanned in order.
The AD7682/AD7689 use a simple SPI interface for writing to
the configuration register and receiving conversion results. The
SPI interface uses a separate supply, VIO, which is set to the
host logic level. Power dissipation scales with throughput.
The AD7682/AD7689 are housed in a tiny 20-lead LFCSP with
operation specified from −40°C to +85°C.
Rev. D
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 that may result from its use. Specifications subject to change without notice. No
license is granted by implication or otherwise under any patent or patent rights of Analog Devices.
Trademarks and registered trademarks are the property of their respective owners.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: [phone]
www.analog.com
Fax: [phone] ©2008–2012 Analog Devices, Inc. All rights reserved.