Panasonic KX-TES824LA Service Manual page 215

26.5.2. Cross Point Switch Circuit
26.5.2.1. Composition
The cross point circuit composed of three cross point switch IC´s. (IC500:8X16, IC501:8X8, IC502:4X8)
1) Cross Point Switch IC Operation
The cross point SW (IC500) contains a 8X16 array of cross point switches along with a 7 to 128 line decoder and latch circuits.
Any one of the 128 switches can be addressed by selecting appropriate seven address bits. The selected switch can be turned
on or off by applying either logical one or zero to the DATA input. Chip select allows the cross point array to be cascaded for
matrix expansion.
The cross point SW (IC501) contains a 8X8 array of cross point switches along with a 6 to 64 line decoder and latch circuits.
Any one of the 64 switches can be addressed by selecting appropriate seven address bits. The selected switch can be turned
on or off by applying either logical one or zero to the DATA input. Chip select allows the cross point array to be cascaded for
matrix expansion.
The cross point SW´s (IC502) contain 4X8 array of cross point switches along with a 5 to 32 line decoder and latch circuits. Any
one of the 32 switches can be addressed by selecting appropriate five address bits. The selected switch can be turned on or
off by applying either logical one or zero to the DATA input. Chip select allows the cross point array to be cascaded for matrix
expansion.
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KX-TES824LA / KX-TEM824LA /