STMicroelectronics M74HC138B 3-to-8 Line Decoder/Demultiplexer

The M74HC138B is a high-speed CMOS 3-to-8 line decoder/demultiplexer manufactured by STMicroelectronics. This integrated circuit is designed to accept three binary weighted address inputs (A0, A1, A2) and, when enabled, provide 8 mutually-exclusive active-LOW outputs (Y0 to Y7).

This device features three enable inputs, two active-LOW (E1, E2) and one active-HIGH (E3). The M74HC138B decoder can be used in a wide range of applications, from hardware addressing in computer systems to the expansion of output lines, such as in microcontroller applications. It is particularly useful in situations where a device is selecting one of multiple options, or routing data to one of several devices.

The M74HC138B is known for its high noise immunity and low power consumption, characteristic of the CMOS technology. It is capable of operating with a supply voltage ranging from 2V to 6V, making it suitable for interfacing with TTL levels as well as many other voltage levels, thus offering great flexibility in system design.

Further features of this decoder/demultiplexer include:

• Low power dissipation: ICC = 4 µA (max) at TA = 25°C
• High noise immunity: VNIH = VNIL = 28% VCC (min)
• Power down protection is provided on all inputs and outputs
• Pin and function compatible with 74 series 138

The M74HC138B is available in several packages, including DIP, SO, and TSSOP, providing flexibility for various PCB layouts and assembly techniques. The device is also characterized for operation from -55°C to +125°C, ensuring reliability over a broad range of environmental conditions.

For seamless integration into electronic systems, the M74HC138B includes latch-up performance that exceeds 100mA per JESD 78, Class II, and it complies with JEDEC standard no. JESD 17. These standards ensure the robustness and reliability of the device in a multitude of applications.

Overall, the STMicroelectronics M74HC138B is a versatile and reliable component for designers looking to implement efficient decoding or demultiplexing functions in their digital systems.