Overview
The SN74HC244PWRE4, produced by Texas Instruments, is an octal buffer and line driver with 3-state outputs. This device is part of the SNx4HC244 family and 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 2 V to 6 V, making it versatile for various applications. The device is organized as two 4-bit buffers and drivers with separate output-enable (OE) inputs, allowing for precise control over data transmission.
Key Specifications
| Parameter | Min | Typ | Max | Unit |
|---|---|---|---|---|
| Supply Voltage Range (VCC) | 2 | 6 | V | |
| Input Clamp Current (IIK) | ±20 | mA | ||
| Output Clamp Current (IOK) | ±20 | mA | ||
| Continuous Output Current (IO) | ±35 | mA | ||
| Continuous Current through VCC or GND | ±70 | mA | ||
| Junction Temperature (TJ) | 150 | °C | ||
| Storage Temperature (Tstg) | -65 | 150 | °C | |
| Propagation Delay Time (tpd) at VCC = 5 V | 11 | ns | ||
| Output Drive at VCC = 5 V | ±6 | mA | ||
| Input Current (II) | 1 | µA | ||
| Power Consumption (ICC) | 80 | µA |
Key Features
- Wide operating voltage range of 2 V to 6 V
- High-current outputs drive up to 15 LSTTL loads
- 3-state outputs drive bus lines or buffer memory address registers
- Low power consumption: ICC, 80 µA (maximum)
- Typical propagation delay time (tpd) of 11 ns at VCC = 5 V
- ±6 mA output drive at VCC = 5 V
- Low input current of 1 µA (maximum)
- Separate output-enable (OE) inputs for each 4-bit buffer
- High-impedance state when OE is high
Applications
- Servers
- LED Displays
- Network Switches
- Telecom Infrastructure
- Motor Drivers
- I/O Expanders
The SN74HC244 is particularly useful in bus interface type applications where output drive or PCB trace length is a concern.
Q & A
- What is the operating voltage range of the SN74HC244?
The operating voltage range is from 2 V to 6 V.
- How many LSTTL loads can the SN74HC244 drive?
The SN74HC244 can drive up to 15 LSTTL loads.
- What is the typical propagation delay time (tpd) at VCC = 5 V?
The typical propagation delay time is 11 ns.
- What is the output drive capability at VCC = 5 V?
The device can drive ±6 mA at VCC = 5 V.
- What is the maximum input current?
The maximum input current is 1 µA.
- How does the output-enable (OE) input function?
When OE is low, the device passes noninverted data from the A inputs to the Y outputs. When OE is high, the outputs are in the high-impedance state.
- What are some common applications for the SN74HC244?
Common applications include servers, LED displays, network switches, telecom infrastructure, motor drivers, and I/O expanders.
- What is the maximum junction temperature for the SN74HC244?
The maximum junction temperature is 150 °C.
- What is the storage temperature range for the SN74HC244?
The storage temperature range is from -65 °C to 150 °C.
- How should the OE input be managed during power-up or power-down to ensure the high-impedance state?
The OE input should be tied to VCC through a pullup resistor to ensure the high-impedance state during power-up or power-down.
