a
FEATURES
Autocalibrating
On-Chip Sample-Hold Function
Serial Output
16 Bits No Missing Codes
1 LSB INL
–99 dB THD
92 dB S/(N+D)
1 MHz Full Power Bandwidth
V
IN
AGND SENSE
V
R E F
AGND
10
9
11
8
INPUT
BUFFERS
16-Bit 100 kSPS
Sampling ADC
AD677
FUNCTIONAL BLOCK DIAGRAM
A CHIP
16-BIT
DAC
CAL
DAC
LOGIC TIMING
LEVEL TRANSLATORS
COMP
15 BUSY
14 SCLK
CAL 16
CLK
SAMPLE
2
1
MICROCODED
CONTROLLER
SAR
ALU
RAM
D CHIP
3 SDATA
AD677
PRODUCT DESCRIPTION
PRODUCT HIGHLIGHTS
The AD677 is a multipurpose 16-bit serial 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 AD677 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 AD677 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.
The AD677 operates from +5 V and
±
12 V supplies and typi-
cally consumes 450 mW using a 10 V reference (360 mW with
5 V reference) during conversion. The digital supply (V
DD
) is
separated from the analog supplies (V
CC
, V
EE
) for reduced digi-
tal crosstalk. An analog ground sense is provided to remotely
sense the ground potential of the signal source. This can be use-
ful if the signal has to be carried some distance to the A/D con-
verter. Separate analog and digital grounds are also provided.
The AD677 is available in a 16-pin narrow plastic DIP, 16-pin
narrow side-brazed ceramic package, or 28-lead SOIC. A paral-
lel output version, the AD676, is available in a 28-pin ceramic
or plastic DIP. All models operate over a commercial tempera-
ture range of 0°C to +70°C or an industrial range of –40°C to
+85°C.
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.
1. Autocalibration provides excellent dc performance while
eliminating the need for user adjustments or additional exter-
nal circuitry.
2.
±
5 V to
±
10 V input range (± V
REF
).
3. Available in 16-pin 0.3" skinny DIP or 28-lead SOIC.
4. Easy serial interface to standard ADI DSPs.
5. TTL compatible inputs/outputs.
6. Excellent ac performance: –99 dB THD, 92 dB S/(N+D)
peak spurious –101 dB.
7. Industry leading dc performance: 1.0 LSB INL,
±
1 LSB full
scale and offset.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 617/329-4700
Fax: 617/326-8703
AD [ ANALOG DEVICES ]
