资 源 简 介
CD22101 and CD22102 crosspoint switches consist of4 x 4 x 2 arrays of crosspoints (transmission gates) with a4-line to 16-line decoder and 16 latch circuits. Any one ofthe sixteen crosspoint pairs can be selected by applyingthe appropriate four-line address, correspondingcrosspoints in each array are turned on and offsimultaneously. Any number of crosspoints can be turnedon simultaneously.In the CD22101, the selected crosspoint pair can beturned on or off by applying a logic ONE or ZERO,respecTIvely, to the data input, and applying a ONE to thestrobe input. When the device is “powered up”, the statesof the 16 switches are indeterminate. Therefore, allswitches must be turned off by putTIng the strobe high,data-in low, and then addressing all switches insuccession.The selected pair of crosspoints in the CD22102 is turnedon by applying a logic ONE to the KA (set) input while alogic ZERO is on the KB input, and turned off by applyinga logic ONE to the KB (reset) input while a logic ZERO ison the KA input. In this respect, the control latches of theCD22102 are similar to SET/RESET flip-flops. They differ,however, in that the simultaneous applicaTIon of ONEs tothe KA and KB inputs turns off (resets) all crosspoints. Allcrosspoints in both devices must be turned off as VDD isapplied.
