Variable Resolution, Monolithic
Resolver-to-Digital Converters
a
AD2S81A/AD2S82A
AD2S82A FUNCTIONAL BLOCK DIAGRAM
FEATURES
Monolithic (BiMOS ll) Tracking R/D Converter
Ratiometric Conversion
INTEGRATOR
I/P
DEMOD DEMOD
I/P O/P
Low Power Consumption: 300 mW Typ
Dynamic Performance Set by User
Velocity Output
AD2S82A
PHASE
SENSITIVE
DETECTOR
INTEGRATOR
O/P
SIN I/P
SIGNAL
GND
COS I/P
ANALOG
GND
A1
A2
SEGMENT
SWITCHING
ESD Class 2 Protection (2,000 V Min)
R-2R
DAC
AC ERROR
O/P
A3
AD2S81A
28-Lead DIP Package
Low Cost
RIPPLE
CLK
VCO I/P
INHIBIT
VCO O/P
VCO DATA
TRANSFER
LOGIC
16-BIT
UP/DOWN COUNTER
OUTPUT DATA LATCH
16 DATA BITS
+12V
–12V
AD2S82A
44-Lead PLCC Package
10-, 12-, 14- and 16-Bit Resolution Set by User
High Max Tracking Rate 1040 RPS (10 Bits)
VCO Output (Inter LSB Output)
Data Complement Facility
COMP
+5V
DATA
LOAD
DIGITAL
GND
BUSY DIR
SC2
SC1 ENABLE
BYTE
SELECT
Industrial Temperature Range
An analog signal proportional to velocity is also available and
can be used to replace a tachogenerator.
APPLICATIONS
DC Brushless and AC Motor Control
Process Control
Numerical Control of Machine Tools
Robotics
Axis Control
PRODUCT HIGHLIGHTS
Monolithic. A one-chip solution reduces the package size re-
quired and increases the reliability.
Resolution Set by User. Two control pins are used to select
the resolution of the AD2S82A to be 10, 12, 14 or 16 bits al-
lowing the user to use the AD2S82A with the optimum resolu-
tion for each application.
GENERAL DESCRIPTION
The AD2S82A is a monolithic 10-, 12-, 14- or 16-bit tracking
resolver-to-digital converter contained in a 44-lead J leaded
PLCC package. Two extra functions are provided in the new
surface mount package–COMPLEMENT and VCO output.
Ratiometric Tracking Conversion. Conversion technique
provides continuous output position data without conversion
delay and is insensitive to absolute signal levels. It also provides
good noise immunity and tolerance to harmonic distortion on
the reference and input signals.
The AD2S81A is a monolithic 12-bit fixed resolution tracking
resolver-to-digital converter packaged in a 28-lead DIP.
The converters allow users to select their own dynamic performance
with external components. This allows the users great flexibility in
defining the converter that best suits their system requirements.
The AD2S82A 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.
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 external com-
ponents required are all low cost, preferred value resistors and
capacitors, and the component values are easy to select using
the simple instructions given.
The AD2S81A and AD2S82A convert resolver format input
signals into a parallel natural binary digital word using a ratio-
metric tracking conversion method. This ensures high-noise
immunity and tolerance of lead length when the converter is
remote from the resolver.
Velocity Output. An analog signal proportional to velocity is
available and is linear to typically one percent. This can be used
in place of a velocity transducer in many applications to provide
loop stabilization in servo controls and velocity feedback data.
The output word is in a three-state digital logic form available in
two bytes on the 16 output data lines for the AD2S82A and on
eight output data lines for the AD2S81A. BYTE SELECT,
ENABLE and INHIBIT pins ensure easy data transfer to 8- and
16-bit data buses, and outputs are provided to allow for cycle or
pitch counting in external counters.
Low Power Consumption. Typically only 300 mW.
MODELS AVAILABLE
Information on the models available is given in the Ordering
Guide.
REV. B
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.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781/329-4700
Fax: 781/326-8703
World Wide Web Site: http://www.analog.com
© Analog Devices, Inc., 1998