SCDS019M May 1995 – December 2015 SN74CBT3251
PRODUCTION DATA.
請(qǐng)參考 PDF 數(shù)據(jù)表獲取器件具體的封裝圖。
The SN74CBT3251 device is a single 8-channel multiplexer with three binary control inputs, S0, S1, and S2 and an OE (output enable, active low) input. The three binary signals select 1 of 8 channels to be turned on, and connect one of the 8 inputs to the output.
When they are used as demultiplexers, the CHANNEL IN/OUT terminals (B) are the outputs and the COMMON OUT/IN terminal (A) is the input.
Figure 3. Logic Diagram (Positive Logic)
The SN74CBT3251 1-of-8 FET multiplexers and demultiplexers can accept a wide range of analog signal levels from 0 V to 5 V. It has low Ron resistance, typically 5-Ω for VCC = 5 V which allows very little signal loss through the switch. Binary address decoding on chip makes channel selection easy.
Table 1 lists the functional modes of the SN74CBT3251.
| INPUTS | FUNCTION | |||
|---|---|---|---|---|
| OE | S2 | S1 | S0 | |
| L | L | L | L | A port = B1 port |
| L | L | L | H | A port = B2 port |
| L | L | H | L | A port = B3 port |
| L | L | H | H | A port = B4 port |
| L | H | L | L | A port = B5 port |
| L | H | L | H | A port = B6 port |
| L | H | H | L | A port = B7 port |
| L | H | H | H | A port = B8 port |
| H | X | X | X | Disconnect |