PDSP16350

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PDSP16350

I/Q Splitter/NCO

Supersedes version in December 1993 Digital Video & DSP IC Handbook, HB3923-1

DS3711 - 2.3 September 1996

Fig. 1 Block Diagram

CORDIC PROCESSOR ARRAY

SIN

COS

DIN

MUX

PHASE ACCUM

REGISTER

ACCUM

SCALING

REGISTER

PHASE OFFSET

REGISTER

PHASE INCR

REGISTER

The PDSP16350 provides an integrated solution to the

need for very accurate, digitised, sine and cosine waveforms.

Both these waveforms are produced simultaneously, with 16

bit amplitude accuracy, and are synthesised using a 34 bit

phase accumulator. The more significant bits of this provide

16 bits of phase accuracy for the sine and cosine look up

tables.

With a 20 MHz system clock, waveforms up to 10 MHz can

be produced, with 0.001 Hz resolution. If frequency modula-

tion is required with no discontinuities, the phase increment

value can be changed linearly on every clock cycle. Alterna-

tively absolute phase jumps can be made to any phase value.

The provision of two output multipliers allows the sine and

cosine waveforms to be amplitude modulated with a 16 bit

value present on the input port. This option can also be used

to generate the in-phase and quadrature components from an

incoming signal. This I/Q split function is required by systems

which employ complex signal processing.

FEATURES

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Direct Digital Synthesiser producing simultaneous sine

and cosine values

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16 bit phase and amplitude accuracy, giving spur levels

down to - 90 dB

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Synthesised outputs from DC to 10 MHz with accuracies

better than 0.001 Hz

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Amplitude and Phase modulation modes

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84 pin PGA or 132 pin QFP

APPLICATIONS

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Numerically controlled oscillator (NCO)

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Quadrature signal generator

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FM, PM, or AM signal modulator

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Sweep Oscillator

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High density signal constellation applications with simul-

taneous amplitude and phase modulation

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VHF reference for UHF generators

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Signal demodulator

ASSOCIATED PRODUCTS

PDSP16256/A

Programmable FIR Filter

PDSP16510A

FFT Processor

PDSP16488A

2D Convolver