Overview
The SN74HC240NS is an octal buffer and line driver integrated circuit produced by Texas Instruments. It is designed to enhance the performance and density of 3-state memory address drivers, clock drivers, and bus-oriented receivers and transmitters. The device is organized as two 4-bit buffers/drivers with separate output-enable (OE) inputs. When the OE input is low, the device passes inverted data from the A inputs to the Y outputs. When the OE input is high, the outputs are in the high-impedance state.
Key Specifications
| Parameter | Unit | Min | Typ | Max |
|---|---|---|---|---|
| VCC Supply Voltage | V | 2 | 5 | 6 |
| VIH High-level Input Voltage (VCC = 2 V) | V | 1.5 | 1.5 | |
| VIH High-level Input Voltage (VCC = 4.5 V) | V | 3.15 | 3.15 | |
| VIH High-level Input Voltage (VCC = 6 V) | V | 4.2 | 4.2 | |
| VIL Low-level Input Voltage (VCC = 2 V) | V | 0.5 | 0.5 | |
| VIL Low-level Input Voltage (VCC = 4.5 V) | V | 1.35 | 1.35 | |
| VIL Low-level Input Voltage (VCC = 6 V) | V | 1.8 | 1.8 | |
| Output Drive Current (VCC = 5 V) | mA | ±6 | ||
| Input Current (max) | µA | 1 | ||
| Propagation Delay Time (tpd) A to Y (VCC = 2 V) | ns | 50 | 100 | 150 |
| Propagation Delay Time (tpd) A to Y (VCC = 4.5 V) | ns | 10 | 20 | 30 |
| Propagation Delay Time (tpd) A to Y (VCC = 6 V) | ns | 9 | 17 | 25 |
| Operating Free-Air Temperature | °C | -40 | 85 |
Key Features
- Wide operating voltage range of 2 V to 6 V
- High-current outputs drive up to 15 LSTTL loads
- Low power consumption, 80 µA max ICC
- Typical propagation delay time (tpd) of 9 ns at VCC = 6 V
- ±6 mA output drive at 5 V
- Low input current of 1 µA max
- 3-state outputs drive bus lines or buffer memory address registers
- Separate output-enable (OE) inputs for each 4-bit buffer/driver
Applications
- 3-state memory address drivers
- Clock drivers
- Bus-oriented receivers and transmitters
- General-purpose buffering and line driving in digital systems
Q & A
- What is the operating voltage range of the SN74HC240NS?
The operating voltage range is from 2 V to 6 V.
- How many LSTTL loads can the outputs of the SN74HC240NS drive?
The outputs can drive up to 15 LSTTL loads.
- What is the maximum power consumption of the SN74HC240NS?
The maximum power consumption is 80 µA.
- What is the typical propagation delay time (tpd) of the SN74HC240NS at VCC = 6 V?
The typical propagation delay time is 9 ns.
- What is the output drive current of the SN74HC240NS at VCC = 5 V?
The output drive current is ±6 mA.
- What is the maximum input current of the SN74HC240NS?
The maximum input current is 1 µA.
- How are the outputs of the SN74HC240NS controlled?
The outputs are controlled by separate output-enable (OE) inputs for each 4-bit buffer/driver.
- What happens to the outputs when the OE input is high?
When the OE input is high, the outputs are in the high-impedance state.
- What are some common applications of the SN74HC240NS?
Common applications include 3-state memory address drivers, clock drivers, and bus-oriented receivers and transmitters.
- What is the operating temperature range of the SN74HC240NS?
The operating free-air temperature range is from -40°C to 85°C.
