Variable Resolution,
Resolver-to-Digital Converter
a
AD2S83
FEATURES
Tracking R/D Converter
FUNCTIONAL BLOCK DIAGRAM
REFERENCE
High Accuracy Velocity Output
High Max Tracking Rate 1040 RPS (10 Bits)
44-Lead PLCC Package
10-, 12-, 14- or 16-Bit Resolution Set by User
Ratiometric Conversion
OFFSET ADJUST
R9
+12V
I/P
HF FILTER
–12V
C3
R8
R3
R2
C2
C1
R1
BANDWIDTH
SELECTION
R4
Stabilized Velocity Reference
Dynamic Performance Set by User
Industrial Temperature Range
INTEGRATOR
I/P
AC ERROR O/P
C5
R5
DEMOD
O/P
C4
SIN
SIG
GND
A1
A2
PHASE
SENSITIVE
DETECTOR
SEGMENT
SWITCHING
A3
APPLICATIONS
DC and AC Servo Motor Control
Process Control
Numerical Control of Machine Tools
Robotics
Axis Control
R – 2R DAC
INTEGRATOR
VELOCITY
SIGNAL
O/P
COS
GND
R6
AD2S83
TRACKING
RATE
SELECTION
RIPPLE
CLOCK
VCO
I/P
16-BIT UP/DOWN COUNTER
OUTPUT DATA LATCH
VCO
+ DATA
TRANSFER
LOGIC
+12V
–12V
C7
VCO
O/P
R7
3K3
C6
390pF
SC2
DATA SC1
LOAD
ENABLE
+5V
BYTE
SELECT
BUSY DIRECTION INHIBIT
DIG
GND
16
DATA BITS
GENERAL DESCRIPTION
PRODUCT HIGHLIGHTS
The AD2S83 is a monolithic 10-, 12-, 14- or 16-bit tracking
resolver-to-digital converter.
High Accuracy Velocity Output. A precision analog velocity
signal with a typical linearity of ±0.1% and reversion error less
than ±0.3% is generated by the AD2S83. The provision of this
signal removes the need for mechanical tachogenerators used in
servo systems to provide loop stabilization and speed control.
The converter allows users to select their own resolution and dy-
namic performance with external components. The converter allows
users to select the resolution to be 10, 12, 14 or 16 bits and to
track resolver signals rotating at up to 1040 revs per second
(62,400 rpm) when set to 10-bit resolution.
Resolution Set by User. Two control pins are used to select
the resolution of the AD2S83 to be 10, 12, 14 or 16 bits allow-
ing optimum resolution for each application.
The AD2S83 converts resolver format input signals into a paral-
lel natural binary digital word using a ratiometric tracking con-
version method. This ensures high noise immunity and tolerance of
long leads allowing the converter to be located remote from the
resolver.
Ratiometric Tracking Conversion. This technique provides
continuous output position data without conversion delay. It
also provides noise immunity and tolerance of harmonic distor-
tion on the reference and input signals.
The position output from the converter is presented via 3-state
output pins which can be configured for operations with 8- or
16-bit bus. BYTE SELECT, ENABLE and INHIBIT pins
ensure easy data transfer to 8- and 16-bit data bus, and outputs
are provided to allow for cycle or pitch counting in external
counters.
Dynamic Performance Set by the User. By selecting exter-
nal resistor and capacitor values the user can determine band-
width, maximum tracking rate and velocity scaling of the
converter to match the system requirements. The component
values are easy to select using the free component selection
software design aid.
A precise analog signal proportional to velocity is also available
and will replace a tachogenerator.
MODELS AVAILABLE
Information on the models available is given in the Ordering
Guide.
The AD2S83 operates over reference frequencies in the range
0 Hz to 20,000 Hz.
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
which may result from its use. No license is granted by implication or
otherwise under any patent or patent rights of Analog Devices.
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Tel: 781/329-4700
Fax: 781/326-8703
World Wide Web Site: http://www.analog.com
© Analog Devices, Inc., 1998