The AD2S1205 is a complete 12-bit resolution tracking resolver-to-digital converter that contains an on-board programmable sinusoidal oscillator providing sine wave excitation for resolvers.
The converter accepts 3.15 V p-p ± 27% input signals on the Sin and Cos inputs. A Type II tracking loop is employed to track the inputs and convert the input Sin and Cos information into a digital representation of the input angle and velocity. The maximum tracking rate is a function of the external clock frequency. The performance of the AD2S105 is specified across a frequency range of 8.192 MHz ± 25%, allowing a maximum tracking rate of 1250 rps.
- Ratiometric Tracking Conversion. The Type II tracking loop provides continuous output position data without conversion delay. It also provides noise immunity and tolerance of harmonic distortion on the reference and input signals.
- System Fault Detection. A fault detection circuit can sense loss of resolver signals, out-of-range input signals, input signal mismatch, or loss of position tracking.
- Input Signal Range. The Sin and Cos inputs can accept differential input voltages of 3.15 V p-p ± 27%.
- Programmable Excitation Frequency. Excitation frequency is easily programmable to 10 kHz, 12 kHz, 15 kHz, or 20 kHz by using the frequency select pins (the FS1 and FS2 pins).
- Triple Format Position Data. Absolute 12-bit angular position data is accessed via either a 12-bit parallel port or a 3-wire serial interface. Incremental encoder emulation is in standard A-quad-B format with direction output available.
- Digital Velocity Output. 12-bit signed digital velocity accessed via either a 12-bit parallel port or a 3-wire serial interface.
Data Sheet, Rev. 0, 1/07
The AD2S1200 is a complete 12-bit resolution tracking resolver-to-digital converter, integrating an on-board programmable sinusoidal oscillator that provides sine wave excitation for resolvers. An external 8.192 MHz crystal is required to provide precision time reference. This clock is internally divided to generate a 4.096 MHz clock to drive all the peripherals.
The converter accepts 3.6 V p-p ±10% input signals, in the range of 10 kHz to 20 kHz on the Sin and Cos 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 and velocity. The bandwidth of the converter is set internally to 1.7 kHz with an external 8.192 MHz crystal. The maximum tracking rate is 1,000 rps.
The SDC1740 is a hybrid 14-bit continuous tracking synchro digital converter. In the core of this hybrid, the conversion process is performed by a monolithic IC manufactured in Analog Devices proprietary BiMOS II process that combines the advantages of CMOS logic and bipolar high accuracy linear circuits on the same chip. Internal isolating micro-transformers are used to provide true isolation of the signal and reference inputs. The 14-bit digital word is in a three-state digital form available in two bytes. Using separate ENABLE inputs for the most significant 8 bits and the least significant 6 or 4 bits not only simplifies multiplexing off more than one device onto a single data bus, but also enables the INHIBIT input to be used without interrupting the operation of tracking loop. The converters are hermetically sealed in a 32-pin welded metal package.
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.
The AD2S83 is a monolithic 10-, 12-, 14-, or 16-bit tracking resolver-to-digital converter.
The converter allows users to select their own resolution and dynamic 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.
The AD2S83 converts 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 long leads allowing the converter to be located remote from the resolver.
A precise analog signal proportional to velocity is also available and will replace a tachogenerator. The AD2S83 operates over reference frequencies in the range 0 Hz to 20,000 Hz.
The core of each conversion is performed by state-of-the-art mono-lithic, integrated circuits manufactured by the Analog Devices, Inc., proprietary BiMOS II process, which combines the advantages of low power CMOS digital logic with bipolar linear circuits. The use of these ICs keeps the internal component count low and ensures high reliability.
The built-in test (BIT) facility can be used in failsafe systems to provide an indication of whether the converter is tracking accurately.
Each channel incorporates a high accuracy differential condi-tioning circuit for signal inputs providing more than 74 dB of common-mode rejection. Options are available for both synchro and resolver format inputs. The converter output is via a three-state transparent latch allowing data to be read without interruption of the converter operation. The A/B and OE control lines select the channel and present the digital position to the common data outputs.
The AD2S44 also features independent reference inputs where different reference frequencies can be used for each channel.
All components are 100% tested at −55°C, +25°C, and +125°C. Devices are processed to high reliability screening standards and receive further levels of testing and screening to ensure high levels of reliability.
The AD2S99 programmable sinusoidal oscillator provides sine wave excitation for resolvers and a wide variety of ac transducers.
The AD2S99 also provides a synchronous reference output signal (3 V p-p square wave) that is phase locked to its SIN and COS inputs. In an application, the SIN and COS inputs are connected to the transducer’s secondary windings. The synchronous reference output compensates for temperature and cabling dependent phase shifts and eliminates the need for external preset phase compensation circuits. The synchronous reference output can be used as a zero crossing reference for resolver-to-digital converters such as Analog Devices’ AD2S80A, AD2S82A, AD2S83 and AD2S90.
The AD2S99 is packaged in a 20-pin PLCC and operates over –40ºC to +85ºC.