Overview
The SN74HC240NSRE4 is an octal buffer and line driver produced by Texas Instruments. This device is designed to enhance the performance and density of 3-state memory address drivers, clock drivers, and bus-oriented receivers and transmitters. It operates within a wide voltage range of 2V to 6V, making it versatile for various applications. The SN74HC240 is organized as two 4-bit buffers/drivers with separate output-enable (OE) inputs, allowing for precise control over the output states.
Key Specifications
| Parameter | Min | Typ | Max | Unit |
|---|---|---|---|---|
| VCC Supply Voltage | 2 | 5 | 6 | V |
| VIH High-Level Input Voltage (VCC = 2V) | 1.5 | 1.5 | V | |
| VIH High-Level Input Voltage (VCC = 4.5V) | 3.15 | 3.15 | V | |
| VIH High-Level Input Voltage (VCC = 6V) | 4.2 | 4.2 | V | |
| VIL Low-Level Input Voltage (VCC = 2V) | 0.5 | 0.5 | V | |
| VIL Low-Level Input Voltage (VCC = 4.5V) | 1.35 | 1.35 | V | |
| VIL Low-Level Input Voltage (VCC = 6V) | 1.8 | 1.8 | V | |
| TA Operating Free-Air Temperature | -40 | 85 | °C | |
| tpd Propagation Delay Time (A to Y) at VCC = 2V | 50 | 100 | 150 | ns |
| tpd Propagation Delay Time (A to Y) at VCC = 4.5V | 10 | 20 | 30 | ns |
| tpd Propagation Delay Time (A to Y) at VCC = 6V | 9 | 17 | 25 | ns |
| IO Output Current | ±6 | mA | ||
| ICC Quiescent Supply Current | 80 | µA |
Key Features
- Wide operating voltage range of 2V to 6V
- High-current outputs drive up to 15 LSTTL loads
- Low power consumption, with a maximum ICC of 80µA
- Typical propagation delay time (tpd) of 9ns at VCC = 6V
- ±6mA output drive at 5V
- Low input current of 1µA 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 driving applications
Q & A
- What is the operating voltage range of the SN74HC240?
The SN74HC240 operates within a voltage range of 2V to 6V.
- What is the maximum output current of the SN74HC240?
The device can drive up to ±6mA at 5V.
- What is the typical propagation delay time of the SN74HC240?
The typical propagation delay time (tpd) is 9ns at VCC = 6V.
- How many bits does the SN74HC240 buffer/driver handle?
The SN74HC240 is organized as two 4-bit buffers/drivers.
- What is the purpose of the output-enable (OE) inputs?
The OE inputs control whether the outputs are in the high-impedance state or pass inverted data from the A inputs to the Y outputs.
- What is the recommended bypass capacitor for the power supply?
A 0.1μF capacitor is recommended, and it is acceptable to parallel multiple bypass capacitors to reject different frequencies of noise.
- What are the package options available for the SN74HC240?
The device is available in various packages including SOIC, PDIP, SOP, SSOP, TSSOP, and others.
- What is the operating temperature range for the SN74HC240?
The operating temperature range is -40°C to 85°C.
- How does the SN74HC240 handle unused inputs?
All unused inputs must be held at VCC or GND to ensure proper device operation.
- What are some common applications of the SN74HC240?
Common applications include 3-state memory address drivers, clock drivers, and bus-oriented receivers and transmitters.
