The IDT54/74FCT138 is a 1-of-8 decoder built using an advanced dual metal CMOS technology. The IDT54/74FCT138 accepts three binary weighted inputs (A0, A1, A2) and, when enabled, provides eight mutually exclusive active LOW outputs (O0-O7). The IDT54/74FCT138 features three enable inputs, two active LOW (E1, E2) and one active HIGH (E3). All outputs will be HIGH unless E1 and E2 are LOW and E3 is HIGH. This multiple enable function allows easy parallel expansion of the device to a 1-of-32 (5 lines when 1-of-32).
This document is a datasheet for the IDT54/74FCT138, IDT54/74FCT138A, and IDT54/74FCT138C, which are 1-of-8 decoders built using advanced dual metal CMOS technology. These devices accept three binary weighted inputs and provide eight mutually exclusive active LOW outputs when enabled. They feature three enable inputs to allow for easy parallel expansion to a 1-of-32 decoder.
| Device Type | 1-of-8 Decoder |
|---|---|
| Technology | Advanced dual metal CMOS |
| Inputs | Three binary weighted inputs (Ao, A1, A2) |
| Outputs | Eight mutually exclusive active LOW outputs (O0 - O7) |
| Output Drive (Commercial) | 48mA |
| Output Drive (Military) | 32mA |
| Power Consumption (Typical Static) | 1 mW |
| Operating Temperature (Commercial) | 0 to +70°C |
| Operating Temperature (Military) | -55°C to +125°C |
The IDT54/74FCT138A is 35% faster than the standard FAST speed, and the IDT54/74FCT138C is 40% faster than the standard FAST speed.
Yes, the multiple enable function allows easy parallel expansion to a 1-of-32 decoder using four devices and one inverter.
Yes, they feature TTL input and output level compatibility.