Overview
The SN74HC257DR is a quad 2-line to 1-line data selector/multiplexer integrated circuit produced by Texas Instruments. This device is part of the 74HC series, known for its high-speed and low-power CMOS logic. It is designed to multiplex signals from 4-bit data sources to 4-output data lines in bus-organized systems, making it suitable for a variety of digital logic applications.
Key Specifications
| Parameter | Min | Typ | Max | Unit |
|---|---|---|---|---|
| Supply Voltage (VCC) | 2 | 5 | 6 | V |
| Operating Temperature Range | -40 | 85 | °C | |
| High-Level Input Voltage (VIH) | 1.5 (VCC=2V), 3.15 (VCC=4.5V), 4.2 (VCC=6V) | V | ||
| Low-Level Input Voltage (VIL) | 0.3 (VCC=2V), 0.9 (VCC=4.5V), 1.2 (VCC=6V) | V | ||
| Input Transition Rise/Fall Time | 1000 (VCC=2V), 500 (VCC=4.5V), 400 (VCC=6V) | ns | ||
| Propagation Delay Time (tpd) | 9 (VCC=6V) | 25 | ns | |
| Output Drive Current | ±6 | mA | ||
| Input Current | 1 | µA | ||
| Package Type | SOIC - D | |||
| Pins | 16 |
Key Features
- Wide operating voltage range of 2 V to 6 V.
- High-current inverting outputs drive up to 15 LSTTL loads.
- Low power consumption, with a maximum ICC of 80 µA.
- Typical propagation delay time of 9 ns.
- ±6-mA output drive at 5 V.
- Low input current of 1 µA max.
- Provides bus interface from multiple sources in high-performance systems.
- 3-state outputs do not load the data lines when the output-enable (G) input is at a high logic level.
Applications
- Bus-organized systems requiring data multiplexing.
- High-performance digital logic circuits.
- Systems needing low power consumption and high-speed data transfer.
- Embedded systems and microcontrollers requiring efficient data routing.
Q & A
- What is the operating voltage range of the SN74HC257DR?
The operating voltage range is from 2 V to 6 V. - What is the typical propagation delay time of the SN74HC257DR?
The typical propagation delay time is 9 ns at 6 V. - How many LSTTL loads can the outputs drive?
The outputs can drive up to 15 LSTTL loads. - What is the maximum input current?
The maximum input current is 1 µA. - What is the package type of the SN74HC257DR?
The package type is SOIC - D. - How many pins does the SN74HC257DR have?
The device has 16 pins. - What is the operating temperature range of the SN74HC257DR?
The operating temperature range is from -40°C to 85°C. - What is the purpose of the 3-state outputs in the SN74HC257DR?
The 3-state outputs do not load the data lines when the output-enable (G) input is at a high logic level. - How does the SN74HC257DR handle power-up and power-down states?
To ensure the high-impedance state during power up or power down, the output-enable (G) input should be tied to VCC through a pull-up resistor. - What are some common applications of the SN74HC257DR?
Common applications include bus-organized systems, high-performance digital logic circuits, and systems requiring low power consumption and high-speed data transfer.
