AD2S90 Low Cost, Complete 12-Bit Resolver-to-Digital Converter

The AD2S90 is a complete 12-bit resolution tracking resolver-to- digital converter. No external components are required to operate the device.

The converter accepts 2 V rms ± 10% input signals in the range 3 kHz-20 kHz on the SIN, COS and REF inputs. A Type II servo loop is employed to track the inputs and convert the input SIN and COS information into a digital representation of the input angle. The bandwidth of the converter is set internally at 1 kHz. The maximum tracking rate is 375 rps at 12-bit resolution.

Angular position output information is available in two forms, absolute serial binary and incremental A quad B.

The absolute serial binary output is 12-bit (1 in 4096). The data output pin is high impedance when Chip Select CS is logic HI. This allows the connection of multiple converters onto a common bus. Absolute angular information in serial pure binary form is accessed by CS followed by the application of an external clock (SCLK) with a maximum rate of 2 MHz.

The encoder emulation outputs A, B and NM continuously produce signals equivalent to a 1024 line encoder.

When decoded this corresponds to 12-bits resolution. Three common north marker pulse widths are selected via a single pin (NMC).

An analog velocity output signal provides a representation of velocity from a rotating resolver shaft traveling in either a clockwise or counterclockwise direction.

The AD2S90 operates on a ±5 V dc ± 5% power supplies and is fabricated on Analog Devices' Linear Compatible CMOS process (LC2MOS). LC2MOS is a mixed technology process that combines precision bipolar circuits with low power CMOS logic circuits.

Features and Benefits
  • Complete Monolithic Resolver-to-Digital Converter
  • Incremental Encoder Emulation (1024-Line)
  • Absolute Serial Data (12-Bit)
  • Differential Inputs
  • 12-Bit Resolution
  • Industrial Temperature Range
  • 20-Lead PLCC
  • Low Power (50 mW)
Analog to Digital Converters
Data Sheets
Documentnote
AD2S90: Low Cost, Complete 12-Bit Resolver-to-Digital Converter Data Sheet (Rev. D)PDF 168 kB
Application Notes
Documentnote
AN-234: Digital Resolver IntegrationPDF 133 kB
AN-264: Dynamic Characteristics of Tracking ConverterPDF 205 kB
AN-263: Resolver to Digital Conversion; Simple Alternative to Optical Shaft EncodersPDF 520 kB
AN-230: Circuit Applications of the AD2S90 R/D ConverterPDF 240 kB
Order Information
Part NumberPackagePacking QtyTemp RangePrice 100-499Price 1000+RoHS
AD2S90AP Production20 ld PLCCOTH 49-40 to 85C37.4232.09N
AD2S90APZ Production20 ld PLCCOTH 49-40 to 85C34.0829.22Y
AD2S90APZ-RL7 Production20 ld PLCCREEL 0-40 to 85C00Y
Reference Materials
AD2S90: Low Cost, Complete 12-Bit Resolver-to-Digital Converter Data Sheet (Rev. D) ad2s90
AN-234: Digital Resolver Integration ad2s80a
AN-264: Dynamic Characteristics of Tracking Converter ad2s80a
AN-263: Resolver to Digital Conversion; Simple Alternative to Optical Shaft Encoders ad2s80a
AN-230: Circuit Applications of the AD2S90 R/D Converter ad2s90
Resolver to Digital Converter Component Part Guide ad2s80a
Single Chip DSP Motor Control Systems Catching on in Home Appliances ad2s80a
DSP Motor Control in Domestic Appliance Applications ad2s80a