AT76C001

Features:

· 4 Multiplier-Accumulators
· 40 Bits Accuracy
· 16 Bit Data and Coefficients
· 4-tap Filter With 27 MHz Sample Rate
· Programmable to Give up to 256 Taps With Sampling Reducing Proportionally to 421,875 kHz
· Programmable Rounding and Truncation to 16 Bit
· 8 Bit Standard Microprocessor Interface
· 64-pin PQFP, 68-pin PGA68 or 68-pin LCC68 Packaging


Application

· Digital Filters (video, audio, etc.)
· Correlation
· Image Processing


Pinout




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	-0.5	VDD+0.5V	V	or see +-IOk
+-IIk	DC input diode		10	mA	VI<-0.5V VI>VDD+0.5V
+-IOk	DC output diode current		20	mA	VO<-0.5V VO>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 AT76C001 Programmable Finite Impulse Response (FIR) Filter implements a 4th order FIR cell built around 4 multiplier-accumulators. It contains a dual-port RAM and a RAM which are used to implement FIR filters of up to 256 taps. High order filters are achieved by multiplexing the 4th order cell and accumulating the intermediate results up to 40 bits, so that there is no loss of accuracy.

The maximum frequency of the AT76C001 is 27 MHz. For 4-tap FIR filter, the incoming sample rate can be as high as 27 MHz. For higher order FIR filters, the sample rate can be as high as the circuit frequency divided by the 4th order cell multiplexing factor.

A programmable normalization block allows the choice of the 16 significant bits from the 40 bit internal result which can be previously rounded by adding 0.5 LSB according to the 16 significant bit locations. The AT76C001 has a microprocessor interface which can be configured to be Intel or Motorola compatible.