FEATURES
Monolithic (BiMOS ll) Tracking R/D Converter
Ratiometric Conversion
Low Power Consumption: 300 mW Typ
Dynamic Performance Set by User
Velocity Output
ESD Class 2 Protection (2,000 V Min)
AD2S81A
28-Lead DIP Package
Low Cost
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
Industrial Temperature Range
APPLICATIONS
DC Brushless and AC Motor Control
Process Control
Numerical Control of Machine Tools
Robotics
Axis Control
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.
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 performancewith 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.
The AD2S81A and AD2S82A convert resolver format input
signals into a parallel natural binary digital word using a ratiometric tracking conversion method. This ensures high-noise
immunity and tolerance of lead length when the converter is
remote from the resolver.
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.
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.
Resolver-to-Digital Converters
AD2S81A/AD2S82A
AD2S82A FUNCTIONAL BLOCK DIAGRAM
An analog signal proportional to velocity is also available and
can be used to replace a tachogenerator.
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 allowing the user to use the AD2S82A with the optimum resolution for each application.
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.
Dynamic Performance Set by the User. By selecting external resistor and capacitor values the user can determine bandwidth, maximum tracking rate and velocity scaling of the
converter to match the system requirements. The external components required are all low cost, preferred value resistors and
capacitors, and the component values are easy to select using
the simple instructions given.
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.
Low Power Consumption. Typically only 300 mW.
MODELS AVAILABLE
Information on the models available is given in the Ordering
Guide.
Specifications subject to change without notice.
All min and max specifications are guaranteed. Specifications in boldface are tested on all production units at final electrical test.
REV. B
–3–
AD2S81A/AD2S82A–SPECIFICATIONS
(typical @ +25ⴗC unless otherwise noted)
ParameterConditionsMinTypMaxMinTypMaxUnits
RATIO MULTIPLIER
AC Error Output Scaling10 Bit177.6mV/Bit
PHASE SENSITIVE DETECTOR
Output Offset Voltage1212mV
Gain
In Phasew.r.t. REF–0.882 –0.9–0.918–0.882 –0.9–0.918V rms/V dc
In Quadraturew.r.t. REF0.040.04V rms/V dc
Input Bias Current6015060150nA
Input Impedance11MΩ
Input Voltage±8±8V
INTEGRATOR
Open-Loop GainAt 10 kHz57635763dB
Dead Zone Current (Hysteresis)100100nA/LSB
Input Offset Voltage1515mV
Input Bias Current6015060150nA
AD2S81AJD30 arc min0°C to +70°CD-28
AD2S82AHP22 arc min–40°C to +85°CP-44A
AD2S82AJP8 arc min–40°C to +85°CP-44A
AD2S82AKP4 arc min–40°C to +85°CP-44A
AD2S82ALP2 arc min–40°C to +85°CP-44A
The AD2S81A and AD2S82A features an input protection circuit consisting of large “distributed”
diodes and polysilicon series resistors to dissipate both high energy discharge (Human Body Model)
and fast, low energy pulses (Charges Device Model).
T
he AD2S81A and AD2S82A is ESD protection Class II (2000 V min). Proper ESD precautions are
strongly recommended to avoid functional damage or performance degradation. For further information on ESD precautions, refer to Analog Devices ESD Prevention Manual.
–4–
WARNING!
ESD SENSITIVE DEVICE
REV. B
AD2S81A/AD2S82A
REFERENCE I/P
DEMOD I/P
DEMOD O/P
INTEGRATOR O/P
ANALOG GND
SIN I/P
+V
S
–V
S
RIPPLE CLK
DIR
AC ERROR O/P
COS I/P
INTEGRATOR I/P
VCO I/P
MSB DB1
BUSY
DB2
DIGITAL GND
DB3
DB4BYTE SELECT
DB5
DB6
+V
L
DB7DB8 LSB
TOP VIEW
(Not to Scale)
28
27
26
25
24
23
22
21
20
19
18
17
16
15
1
2
3
4
5
6
7
8
9
10
11
12
13
14
AD2S81A
INHIBIT
ENABLE
7
8
9
10
11
12
13
14
15
16
17
6 5 4 3 2 1 44 43 42 41 40
39
38
37
36
35
34
33
32
31
30
29
18 19 20 21 22 23 24 25 26 27 28
PIN 1
IDENTIFIER
TOP VIEW
(Not to Scale)
NC = NO CONNECT
–V
S
RIPPLE CLK
DIR
BUSY
DATA LOAD
COMPLEMENT
SC2
SC1
DIGITAL GND
INHIBIT
NC
SIN O/P
+V
S
MSB DB1
NC
DB2
DB3
DB4
DB5
DB6
DB7
DB8
DB9
DB10
DB11
DB12
DB14
DB15
LSB DB16
+V
L
ENABLE
BYTE
SELECT
DB13
AD2S82A
SIGNAL GND
ANALOG GND
COS I/P
AC ERROR O/P
DEMOD I/P
REFERENCE I/P
DEMOD O/P
INTEGRATOR O/P
INTEGRATOR I/P
VCO O/P
VCO I/P
RECOMMENDED OPERATING CONDITIONS
Power Supply Voltage (+VS to –V
Power Supply Voltage V
. . . . . . . . . . . . . . . . . . +5 V dc ±10%
L
) . . . . . . . . . ±12 V dc ±10%
S
Analog Input Voltage (SIN and COS) . . . . . . . . 2 V rms ±10%
Analog Input Voltage (REF) . . . . . . . . . . . . . . 1 V to 8 V peak
Signal and Reference Harmonic Distortion . . . . . . . 10% (max)
Phase Shift Between Signal and Reference . ±10 Degrees (max)
REFERENCE I/PReference Signal Input
DEMOD I/PDemodulator Input
AC ERROR O/PRatio Multiplier Output
COS I/PCosine Input
ANALOG GNDPower Ground
SIGNAL GNDResolver Signal Ground
SIN I/PSine Input
+V
S
DB1–DB16Parallel Output Data
+V
L
ENABLELogic Hi-Output Data in High Impedance
BYTE SELECTLogic Hi-Most Significant Byte to DB1–DB8
INHIBITLogic Lo Inhibits Data Transfer to Output Latches
DIGITAL GNDDigital Ground
SC1–SC2*Select Converter Resolution
DATA LOAD*Logic Lo DB1–DB16 Inputs
BUSYConverter Busy, Data Not Valid While Busy Hi
DIRLogic State Defines Direction of Input Signal Rotation
RIPPLE CLKPositive Pulse when Converter Output Changes from