FUNCTIONAL BLOCK DIAGRAM
DIGITAL
CHIP
PAT
GEN
ALU
RAM
MICRO-CODED
CONTROLLER
AGND
AGND SENSE
CAL
SAMPLE
BUSY
COMP
ANALOG
CHIP
16-BIT
DAC
INPUT
BUFFERS
LOGIC & TIMING
CAL
DAC
LEVEL TRANSLATORS
16
BIT 1 – BIT 16
V
IN
V
REF
15
14
16
13
8
9
AD676
SAR
1
6
19
28
CLK 10
L
A
T
C
H
7
REV. A
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
16-Bit 100 kSPS
Sampling ADC
AD676
FEATURES
Autocalibrating
On-Chip Sample-Hold Function
Parallel Output Format
16 Bits No Missing Codes
61 LSB INL
–97 dB THD
90 dB S/(N+D)
1 MHz Full Power Bandwidth
PRODUCT DESCRIPTION
The AD676 is a multipurpose 16-bit parallel output analog-to-
digital converter which utilizes a switched-capacitor/charge
redistribution architecture to achieve a 100 kSPS conversion
rate (10 µs total conversion time). Overall performance is opti-
mized by digitally correcting internal nonlinearities through
on-chip autocalibration.
The AD676 circuitry is segmented onto two monolithic chips—
a digital control chip fabricated on Analog Devices DSP CMOS
process and an analog ADC chip fabricated on our BiMOS II
process. Both chips are contained in a single package.
The AD676 is specified for ac (or “dynamic”) parameters such
as S/(N+D) Ratio, THD and IMD which are important in sig-
nal processing applications. In addition, dc parameters are
specified which are important in measurement applications.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 617/329-4700 Fax: 617/326-8703
The AD676 operates from +5 V and ±12 V supplies and typi-
cally consumes 360 mW during conversion. The digital supply
(V
DD
) is separated from the analog supplies (V
CC
, V
EE
) for re-
duced digital crosstalk. An analog ground sense is provided for
the analog input. Separate analog and digital grounds are also
provided.
The AD676 is available in a 28-pin plastic DIP or 28-pin side-
brazed ceramic package. A serial-output version, the AD677, is
available in a 16-pin 300 mil wide ceramic or plastic package.
