Overview
The MC74HC138ADR2 is a high-performance silicon-gate CMOS 3-to-8 line decoder/demultiplexer produced by onsemi. This device is identical in pinout to the LS138 and is designed to decode a three-bit address to one of eight active-low outputs. It features three Chip Select inputs, two active-low and one active-high, which facilitate demultiplexing, cascading, and chip-selecting functions. The inputs are compatible with standard CMOS outputs and, with pull-up resistors, can also interface with LSTTL outputs. This makes the MC74HC138ADR2 versatile for various logic level interfaces, including CMOS, NMOS, and TTL.
Key Specifications
| Parameter | Min | Typ | Max | Unit |
|---|---|---|---|---|
| Operating Voltage Range | 2.0 | - | 6.0 | V |
| Input Current | - | - | 1.0 | μA |
| Output Drive Capability | - | - | 10 | LSTTL Loads |
| Output Current (High/Low) | - | - | 5.2 | mA |
| Operating Temperature Range | -55 | - | 125 | °C |
| Package Type | - | - | 16-TSSOP | - |
Key Features
- Decodes three binary weighted address inputs (A0, A1, and A2) to eight mutually exclusive active-low outputs (Y0 to Y7).
- Wide supply voltage range from 2.0 to 6.0 V, making it compatible with various power supply systems.
- CMOS low power dissipation and high noise immunity characteristic of CMOS devices.
- Output drive capability of 10 LSTTL loads and high current outputs of 5.2 mA for both high and low states.
- Multiple input enable for easy expansion and cascading.
- Ideal for memory chip select decoding and other applications requiring logic signal decoding.
- Complies with JEDEC standards: JESD8C (2.7 V to 3.6 V) and JESD7A (2.0 V to 6.0 V).
- ESD protection: HBM JESD22-A114F exceeds 2000 V and MM JESD22-A115-A exceeds 200 V.
Applications
- Memory chip select decoding in computer systems and other digital memory applications.
- Instrumentation and control systems where precise logic signal decoding is required.
- LED displays, servers, white goods, power infrastructure, building automation, and factory automation.
- High-speed memory decoders and data-transmission systems.
Q & A
- What is the operating voltage range of the MC74HC138ADR2?
The operating voltage range is from 2.0 V to 6.0 V.
- How many outputs does the MC74HC138ADR2 have?
The device has eight mutually exclusive active-low outputs (Y0 to Y7).
- What is the output drive capability of the MC74HC138ADR2?
The output drive capability is 10 LSTTL loads).
- What are the typical applications of the MC74HC138ADR2?
Typical applications include memory chip select decoding, instrumentation, control systems, LED displays, servers, and other high-speed memory and data-transmission systems).
- What is the package type of the MC74HC138ADR2?
The package type is 16-TSSOP).
- What is the operating temperature range of the MC74HC138ADR2?
The operating temperature range is from -55°C to 125°C).
- Does the MC74HC138ADR2 comply with any JEDEC standards?
Yes, it complies with JEDEC standards: JESD8C (2.7 V to 3.6 V) and JESD7A (2.0 V to 6.0 V)).
- What is the ESD protection level of the MC74HC138ADR2?
The ESD protection level exceeds 2000 V for HBM JESD22-A114F and 200 V for MM JESD22-A115-A).
- Can the MC74HC138ADR2 be used as a level converter?
Yes, the MC74HCT138A version can be used as a level converter for interfacing TTL or NMOS outputs to high-speed CMOS inputs).
- What is the input current of the MC74HC138ADR2?
The input current is typically 1.0 μA).
