Analog Devices

The AD2437 A2B®transceiver provides a multichannel, I2S/TDM link over distances of up to 30 m between nodes. It embeds bidirectional synchronous pulse-code modulation (PCM) data (for example, digital audio), clock, and synchronization signals onto a single-pair differential cable. A2B supports a direct point to point connection and allows multiple, daisy-chained nodes at different locations to contribute and/or consume time division multiplexed channel content.A2B is a single main node, multiple subordinate node system where the transceiver at the host controller is the main node. The main node generates clock, synchronization, and framing for all subordinate nodes. The main A2B transceiver is programmable over a control port (I2C/SPI) for configuration and read back. An extension of the control port protocol is embedded in the A2B data stream. This allows direct access to registers and status information on subordinate transceivers, as well as I2C to I2C, SPI to I2C, or SPI to SPI communication from the host to a peripheral in a subordinate node. SPI to SPI communication between subordinate nodes can be performed directly and does not need to involve the main node.The transceiver can connect directly to general-purpose digital signal processors (DSPs), field-programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), digital microphones, analog-to-digital converters (ADCs), digital-to-analog converters (DACs), and codecs through a multichannel I2S/TDM interface. It also provides a pulse density modulation (PDM) interface for direct connection of up to four PDM digital microphones.The transceiver supports a bus power feature, where the main node supplies voltage and current to the subordinate nodes over the same daisy-chained, single-pair wire or XLR/DMX cable as used for the communication link.The transceiver also supports a broad spectrum of Ethernet cables in which the A2B occupies only one pair of a category (CAT) cable. This frees up the remaining CAT cable pairs for power delivery.APPLICATIONSConference room transducer nodesMusical instrument connectivityDistributed audio systemsPersonal audio zones

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 VP-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 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 VP-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.PRODUCT HIGHLIGHTSRatiometric 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 VP-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.APPLICATIONSAutomotive motion sensing and controlHybrid-electric vehiclesElectric power steeringIntegrated starter generator/alternatorIndustrial motor controlProcess control