PDSP16515A

·  Completely self contained FFT Processor
·  Pin and functionally compatible with the PDSP16510A
·  Expanded  width internal RAM supports up to 1024 complex points
·  18 bit internal data bus with block floating point arithmetic for increased dynamic range
·  500 MIP operation gives 87 microsecond transformation times for 1024 points
·  Up to 45MHz sampling rates with  multiple devices.
·  Up to 85dB noise rejection
·  A choice of internal window operators with no external ROM provide up to 67dB side lobe attenuation.
·  84 pin PGA or 132 pin surface mount package

Supply voltage Vcc                                   -0.5V to 7.0V
Input voltage V_IN                           -0.5V to Vcc + 0.5V
Output voltage V_OUT                     -0.5V to Vcc + 0.5V
Clamp diode current per pin I_K (see note 2)      18mA
Static discharge voltage (HMB)                           500V
Storage temperature T_S                       -65 to 150
Junction Temperature, Commercial                     100
Junction temperature, Industrial                        115
Junction Temperature, Military                           155
Package power dissipation                           5000mW
1. Exceeding these ratings may cause permanent damage.Functional operation under these conditions is not implied.
2. Maximum dissipation or 1 second should not be exceeded,only one output to be tested at any one time.
3. Exposure to absolute maximum ratings for extended periods may affect device reliablity.
4. Current is defined as positive into the device.

The PDSP16515A performs Forward or Inverse Fast Fourier Transforms on complex or real data sets containing up to 1024 points. Data and coefficient input are both represented by 16 bits.  Data is expanded internally to 18 bits and subject to Block Floating Point arithmetic to preserve a greater dynamic range.

An internal RAM is provided which can hold up to 1024 complex data points. This removes the memory transfer bottleneck, inherent in building block solutions. Its organisation allows the PDSP16515A to simultaneously input new data, transform data stored in the RAM, and to output previous results. No external buffering is needed for transforms containing up to 256 points, and the PDSP16515A can be directly connected to an A/D converter to perform continuous transforms.


Either a Hamming or a Blackman-Harris window operator can be internally applied to the incoming real or complex data. The latter gives 67dB side lobe attenuation. The operator values of PDSP16515A are calculated internally and do not require an external ROM nor do they incur any time penalty.

The increased internal bus size together with block floating arithmetic produce up to 85dB of noise rejection.

The PDSP16515A's outputs the real and imaginary components of the frequency bins. These can be directly connected to the PDSP16330 in order to produce magnitude and phase values from the complex data.