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[ TM1-3300 ]
8-Channel Analog I/O CompactPCI Transition Module for SDR-3000 Series Software Defined Radio Subsystems

Benefits Features
  • Supports up to 4 IF input channels and 4 IF output channels per board
  • Supports input signal bandwidths up to of 32 MHz
  • Supports 70 MHz IF generation
  • Bus architecture specifically designed to support ultra-high data rates to/from the PRO-3100 FPGA processing engine
  • Supports time stamping of ADC data
  • Supports signaling required for frequency hopping applications
  • Designed to meet high availability system requirements

Applications

  • Military communications (e.g. JTRS, ACN), Wireless intelligence and surveillance, Commercial wireless (e.g. Satellite gateways, 3G cellular base station prototyping), Wireless test and measurement, Wireless prototyping, Beam forming
  • 6U CompactPCI®-based rear I/O transition module
  • 4 ADC channels @ 80 MHz, 14-bit
  • ADC SFDR >70 dB
  • 4 DAC channels @ 80 MHz, 14-bit
  • DACs support up to 70 MHz direct IF generation via a 2 x interpolation filter (to 160 MSPS)
  • Supports two 640 MB/s busses via cPCI J5 connector (TM1 bus)
  • Hot swappable
  • External frequency reference input for accurate sampling frequency control and time stamping
  • IRIG-B time code input for time stamping
  • Synchronization connector allows up to three TM1-3300 and DDCs/DUCs running on PRO-3100 boards to be synchronized for beam forming
  • External application-specific system clock input
  • Supports control of RF front-end units via general purpose I/O, including four 12-bit ADCs and four 12-bit DACs
  • Four user-programmable LEDs for development and debugging
  • Supported by Spectrumˇ¦s quicComm software library

Description
The TM1-3300 is a CompactPCI transition module designed to work with Spectrumˇ¦s SDR-3000 series software defined radio subsystems. It contains 4 ADCs and 4 DACs, running at sampling rates suitable for most standard IF frequencies, and is specifically designed to achieve exceptional signal to noise performance. It interfaces to any RF translation unit with an analog IF or baseband interface, while digitized data is transferred to/from Spectrumˇ¦s PRO-3100 board via a high-speed digital bus.

The TM1-3300 is installed at the rear of a cPCI chassis, with a Spectrum PRO-3100 installed at the front of the same slot.

ADC Converters
The TM1-3300 uses four Analog Devices AD6645AST-80 14-bit, 80 MSPS ADCs.

[Undersampling]
The AD6645AST-80 is designed for undersampling of signals in the 70-80 MHz IF range, with an input bandwidth of approximately 200 MHz.

On the TM1-3300, the only circuitry between the connector and the ADC is a transformer coupling circuit, which is guaranteed to pass signals from 0.5 MHz to 200 MHz.

[Signal Level Monitors]
In order to make adjustments for varying input signal levels, each ADC has an associated digital signal level monitor. The embedded controller on the PRO-3100 can use the reading from the level monitors to make any necessary gain adjustments in software, or it can directly control the RF front-end via any of the supported interfaces.

DAC Converters
The TM1-3300 uses four Analog Devices AD9772AAST 14-bit, 160 MSPS DACs.

Although the sample rate into the DAC is 80 MSPS, an internal 2x interpolation filter up samples the data to 160 MSPS. This allows direct generation of 70 MHz IF signals by moving aliased frequency components up to frequencies near 160 MHz.

Synchronization
In order to facilitate a wide range of synchronization features in SDR-3000 subsystems, the following features have been implemented on the TM1-3300:

[ADC and DAC Sampling]
The ADCs and DACs are synchronized to a single clock source so that all sampling on the TM1-3300 is coherent, a requirement for many applications.

This synchronization can either be to an on-board or external oscillator.

[ADC Time Stamping]
An IRIG-B GPS-based time stamping feature is included, allowing time-of-year time stamps to be embedded in the ADC data, with a precision of one 80 MHz sample clock. The format is IRIG B002 baseband signal and Positive Plus TT2.

[System Clock Input]
A special system clock input connector connects the signal between the front panel of the TM1-3300 with the FPGAs on the PRO-3100. Any user-defined feature can be implemented using this facility, however the intent is to allow an external device to trigger NCO frequency changes in DDCs/DUCs running in the PRO-3100 FPGAs. This is useful in frequency hopping applications.

[Software Initiated Control Events]
A special feature allows the PRO-3100 embedded controller to initiate synchronization signals on the TM1-3300. A typical use of this feature is to ensure that all ADCs start sampling simultaneously.

[Multiboard Synchronization]
Up to three TM1-3300 boards can be synchronized to each other via the TM sync connector. In this configuration, the first board becomes the master and generates synchronization signals to the others, which are slaves. The following signals are then synchronized across all boards:

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General-Purpose I/O
A series of general-purpose I/O signals are supported on the TM1-3300 to provide to control of the passband center frequencies, gains, and other functions of the RF front-end transceivers unit. These signals can be summarized as follows:

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Software
A comprehensive quicComm library is supplied with the TM1-3300 to provide a simple interface to all board-level control functions. This library actually executes on the PRO-3100 embedded controller. Here are some examples of the quicComm API:

TM13300_SetFilterMode( ) Set filter mode to high pass or low pass for a DAC channel
TM13300_GetLevelMonitorCount ( ) Get the level monitor count for an ADC on the transition module
TM13300_IntEnable ( ) Enable an interrupt to the PRO-3100
TM13300_LedFlash_N ( ) Flash the LED(s) N times