AT76C002

Features:

· 16 Multiplier-Accumulators
· 16 Bit Data and 12 Bit Coefficients, 32 Bit Internal Accuracy
· 16 Banks of 12 Bit Coefficients
· 16 Taps at 33 MHz
· Up to 32 Taps for Symmetrical or Interleaved Zeroed Coefficient Filters at 33 MHz
· Up to 63 Taps for Symmetrical Halfband Filters at 33 MHz
· Programmable Decimation by 2, 4, 8 or 16
· Cascadable Keeping Symmetry Advantages
· Output Gain Multiplier
· Programmable Microprocessor Interface
· 208-pin QFP Package


Application

· High sample rate digital filtering
· Image processing
· Video processing
· Matrix multiplication


Specifications

Symbol	Parameter	Min	Max	Unit	Conditions
VDD	DC supply voltage	-0.5	5.5	V
Vi	DC input voltage	-0.5	VDD + 0.5V	V	or see +-IIk
Vo	DC output voltage		VDD + 0.3V	V	or see +-IOk
+-IIk	DC input diode current		10	mA	Vi<-0.5V Vi>VDD+0.5V
+-IOK	DC output diode current		10	mA	V0<-0.5V V0>VDD+0.5V
IolMAX	Continuous output current		10	mA	Industrial
IohMAX	Continuous output current		10	mA	Industrial
tSH	Time of outputs shorted		5	sec
TA	Temperature range	-40	+85	C	Industrial
TSG	Storage Temperature	-65	+150	C

Description

The AT76C002 FIR filter contains 16 multiplier-accumulators which enable it to implement a 16th order nonsym-metrical FIR filter or a 32nd order symmetrical FIR filter, operating at 33 MHz. Furthermore, it can be configured to implement a 64th order filter where the even order coefficients are zero, also running at 33 MHz. The incoming samples are 16 bit coded, the coefficients are 12 bit coded and the internal accuracy is 32 bits.

The AT76C002 contains 16 banks of 2 bit coefficients that can be selected in one clock cycle. These banks can also be used to perform decimation by 2, 4, 8 or 16 using FIR filters from 32 taps up to 256 taps. In decimation mode, the symmetry capabilities cannot be used.

In order to implement long FIR filters at the highest frequency (i.e. 33 MHz) the circuit AT76C002 can be cascaded, with no limits except the internal accuracy. Symmetry properties can be used in cascade mode. This halves the number of cascaded circuits to implement symmetrical filters.

In order to increase the accuracy of the intermediate results, the AT76C002 includes an output gain multiplier which enables the whole 12 bit dynamic of the coefficients to be used. Cascadability cannot be used in decimation mode.

The AT76C002 includes a 16 bit microprocessor interface that can be configured to be Intel or Motorola compatible.