| 摘要 |
An arbitrary waveform generator (AWG) for producing an analog output current signal includes a random access memory (RAM), a programmable logic device (PLD), a programmable pattern generator, several digital-to analog converters (DACS) and a current multiplexer. The RAM store data sequences representing the analog waveform to be generated. The pattern generator read addresses the RAM causing it to sequentially read out its stored data sequence to the PLD. The PLD routes selected fields of each data sequence word to one or more of the DACs in response to timing signals provided by the pattern generator. Each DAC produces an output current of magnitude determined by its input waveform and range data. The pattern generator also signals the analog multiplexer to sum currents produced by one or more selected DACs to produce the AWG output waveform. The nature of the AWG output waveform is flexibly determined by the nature of the data sequence and the frequency at which it is read out of the RAM, the manner in which the PLD routes the data sequence to the DACs, the value of the range data supplied to each DAC, and the output pattern generated by the pattern generator. The flexible AWG architecture permits the AWG to be appropriately configured for various combinations of output waveform frequency, bandwidth and resolution requirements.
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