74HC series ICs are High-speed logic gates with very low power consumption that utilize advanced silicon-gate CMOS technology and 74HC138 is one of them. It has balanced propagation delay and transition times. 74HC138 ICs are 3-to-8 decoders and Demultiplexers. The three inputs A, B, and C select which output is active where C is the most significant bit (MSB). The selected output is pulled LOW, while the remaining outputs are all HIGH. 74HC138 also has 3 enable input to enable and disable the output. One active high and two active-low enable pins are available which reduces the requirement for external gates or inverters when expanding. An enable input can be used as a data input for demultiplexing applications The 74HC138 ICs have a wide operating range of VCC from 2 V to 6 V. Maximum current consumption is 80 uA through Icc and 1 uA per input pin. And the propagation delay is 15 ns. They can drive 10 LS-TTL loads at a time. Which means that the output pin of the decoder can drive 10 TTL based Low-Power Schottky( LS ) input pins. They can provide 4 mA on outputs at 5 V VCC. They allow inputs and outputs up to VCC. Recommended operating VCC is 5 V. Load Current can reach up to 25 mA per output pin and 50 mA for overall pins in between 0 V to VCC.
|Operating Voltage Range||2.0 to 6.0 V|
|Input Current||1 uA|
|Powering Current||80 uA|
|Output Current at VCC||4 mA|
|Fan-Out||10 LS-TTL Load|
|Propagation Delay||15 ns|
|Temperature Range||-55 °C - 125 °C|