MT8809APR1 参数 Datasheet PDF下载

MT8809

Pin Description

Pin #

19

20-23

24-26

27, 28

Name

V

DD

X7, X5,

X3, X1

Positive Power Supply.

Description

Data Sheet

X7, X5, X3 and X1 Analog (Inputs/Outputs):

these are connected to the X7, X5, X3 and

X1 rows of the switch array.

AX0-AX2

AX0 - AX2 Address Lines (Inputs).

AY0, AY1

AY0 and AY1 Address Lines (Inputs).

Functional Description

The MT8809 is an analog switch matrix with an array size of 8 x 8. The switch array is arranged such that there are

8 columns by 8 rows. The columns are referred to as the Y inputs/outputs and the rows are the X inputs/outputs.

The crosspoint analog switch array will interconnect any X I/O with any Y I/O when turned on and provide a high

degree of isolation when turned off. The control memory consists of a 64 bit write only RAM in which the bits are

selected by the address inputs (AY0-AY2, AX0-AX2). Data is presented to the memory on the DATA input. Data is

asynchronously written into memory whenever both the CS (Chip Select) and STROBE inputs are low and are

latched on the rising edge of STROBE. A logical “1” written into a memory cell turns the corresponding crosspoint

switch on and a logical “0” turns the crosspoint off. Only the crosspoint switches corresponding to the addressed

memory location are altered when data is written into memory. The remaining switches retain their previous states.

Any combination of X and Y inputs/outputs can be interconnected by establishing appropriate patterns in the

control memory. A logical “0” on the RESET input will asynchronously return all memory locations to logical “0”

turning off all crosspoint switches regardless of whether CS is high or low.

Address Decode

The six address inputs along with the STROBE and CS (Chip Select) are logically ANDed to form an enable signal

for the resettable transparent latches. The DATA input is buffered and is used as the input to all latches. To write to

a location, RESET must be high and CS must go low while the address and data are set up. Then the STROBE

input is set low and then high causing the data to be latched. The data can be changed while STROBE is low,

however, the corresponding switch will turn on and off in accordance with the DATA input. DATA must be stable on

the rising edge of STROBE in order for correct data to be written to the latch.

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