PDSP16350
I/Q Splitter/NCO
Supersedes version in December 1993 Digital Video & DSP IC Handbook, HB3923-1
DS3711 - 2.3 September 1996
PDSP16350
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.
DIN
PHASE OFFSET
REGISTER
PHASE INCR
REGISTER
SCALING
REGISTER
ACCUM
MUX
PHASE ACCUM
REGISTER
CORDIC PROCESSOR ARRAY
FEATURES
s
s
s
s
s
Direct Digital Synthesiser producing simultaneous sine
and cosine values
16 bit phase and amplitude accuracy, giving spur levels
down to - 90 dB
Synthesised outputs from DC to 10 MHz with accuracies
better than 0.001 Hz
Amplitude and Phase modulation modes
84 pin PGA or 132 pin QFP
Fig. 1 Block Diagram
SIN
COS
APPLICATIONS
s
s
s
s
s
s
s
Numerically controlled oscillator (NCO)
Quadrature signal generator
FM, PM, or AM signal modulator
Sweep Oscillator
High density signal constellation applications with simul-
taneous amplitude and phase modulation
VHF reference for UHF generators
Signal demodulator
ASSOCIATED PRODUCTS
PDSP16256/A
PDSP16510A
PDSP16488A
Programmable FIR Filter
FFT Processor
2D Convolver
1
MITEL [ MITEL NETWORKS CORPORATION ]
