Overview
The SN74HC240PWR is an octal buffer and line driver produced by Texas Instruments. This component 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 | V | 1.5 (VCC=2V), 3.15 (VCC=4.5V), 4.2 (VCC=6V) | ||
| VIL Low-Level Input Voltage | V | 0.5 (VCC=2V), 1.35 (VCC=4.5V), 1.8 (VCC=6V) | ||
| IOH Output Current | mA | -20 | ||
| tpd Propagation Delay (A to Y) | ns | 9 (VCC=6V), 10 (VCC=4.5V), 50 (VCC=2V) | 17 (VCC=6V), 20 (VCC=4.5V), 100 (VCC=2V) | 25 (VCC=6V), 30 (VCC=4.5V), 150 (VCC=2V) |
| tOE Output Enable Time | ns | 13 (VCC=6V), 15 (VCC=4.5V), 75 (VCC=2V) | 26 (VCC=6V), 30 (VCC=4.5V), 150 (VCC=2V) | 38 (VCC=6V), 45 (VCC=4.5V), 225 (VCC=2V) |
| ICC Power Consumption | µA | 80 | ||
| TJ Junction Temperature | °C | 150 | ||
| Tstg Storage Temperature Range | °C | -65 | 150 |
Key Features
- Wide operating voltage range of 2V to 6V
- High-current outputs drive up to 15 LSTTL loads
- Low power consumption, 80µA max ICC
- Typical propagation delay (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 line driving in digital systems
Q & A
- What is the operating voltage range of the SN74HC240PWR?
The operating voltage range is from 2V to 6V.
- How many LSTTL loads can the SN74HC240PWR drive?
The device can drive up to 15 LSTTL loads.
- What is the typical propagation delay of the SN74HC240PWR at VCC=6V?
The typical propagation delay is 9ns at VCC=6V.
- What is the maximum output current of the SN74HC240PWR?
The maximum output current is ±35 mA.
- What is the purpose of the output-enable (OE) input?
The OE input controls the output state; when low, the device passes inverted data, and when high, the outputs are in the high-impedance state.
- What are the recommended power supply bypass capacitors for the SN74HC240PWR?
A 0.1μF capacitor is recommended, and it is acceptable to parallel multiple bypass capacitors to reject different frequencies of noise.
- What is the junction temperature range for the SN74HC240PWR?
The junction temperature range is up to 150°C.
- What are the common applications of the SN74HC240PWR?
Common applications include 3-state memory address drivers, clock drivers, and bus-oriented receivers and transmitters.
- How many bits are organized in each buffer/driver of the SN74HC240PWR?
Each buffer/driver is organized as two 4-bit buffers/drivers.
- What is the thermal resistance (RθJA) for the TSSOP package of the SN74HC240PWR?
The junction-to-ambient thermal resistance (RθJA) for the TSSOP package is approximately 131.8 °C/W.
