Overview
The 74HCT540D is a high-speed CMOS octal bus buffer integrated circuit manufactured by Toshiba Semiconductor and Storage. This device is fabricated using silicon gate C2MOS technology and is designed to provide high-speed operation while maintaining low power dissipation. The 74HCT540D is an inverting type, meaning it inverts the input signal at the output, and it features 3-state outputs. This makes it suitable for a variety of applications, including level conversion between TTL, NMOS, and CMOS logic levels.
Key Specifications
| Characteristic | Symbol | Min | Typ | Max | Unit | Conditions |
|---|---|---|---|---|---|---|
| Supply Voltage | VCC | -0.5 | 7.0 | V | ||
| Input Voltage | VIN | -0.5 | VCC + 0.5 | V | ||
| Output Voltage | VOUT | -0.5 | VCC + 0.5 | V | ||
| Propagation Delay Time | tPLH, tPHL | 9 | 17 | ns | VCC = 5.5 V, CL = 50 pF | |
| Input Leakage Current | IIN | ±1 | µA | VIN = 0.5 V or 2.4 V | ||
| Quiescent Supply Current | ICC | 4.0 | µA | Ta = 25 °C | ||
| Operating Temperature Range | Topr | -40 | 125 | °C |
Key Features
- Wide Operating Temperature Range: -40°C to 125°C
- High Speed Operation: Propagation delay time (tpd) of 9 ns (typ.) at VCC = 5.5 V
- Low Power Dissipation: Quiescent supply current (ICC) of 4.0 µA (max) at Ta = 25°C
- Compatibility with TTL Outputs: High-level input voltage (VIH) of 2.0 V (min) and low-level input voltage (VIL) of 0.8 V (max)
- Wide Interfacing Ability: Compatible with LSTTL, NMOS, and CMOS logic levels
- 3-State Outputs: Outputs can be set to high-impedance state when either G1 or G2 is high
- Balanced Propagation Delays: tPLH ≈ tPHL
- Static Discharge Protection: All inputs are equipped with protection circuits against static discharge or transient excess voltage
Applications
- Level Conversion: Can be used as a level converter for interfacing TTL or NMOS to High Speed CMOS
- Buffering and Line Driving: Suitable for buffering and driving signals in digital circuits
- High-Speed Digital Systems: Ideal for high-speed digital systems requiring low power consumption and high reliability
- Mixed Logic Systems: Useful in systems that require compatibility with multiple logic families (LSTTL, NMOS, CMOS)
Q & A
- What is the primary function of the 74HCT540D?
The primary function of the 74HCT540D is to act as an octal bus buffer with inverting 3-state outputs, allowing it to buffer and invert digital signals.
- What is the operating temperature range of the 74HCT540D?
The operating temperature range of the 74HCT540D is -40°C to 125°C.
- What is the typical propagation delay time of the 74HCT540D?
The typical propagation delay time (tpd) of the 74HCT540D is 9 ns at VCC = 5.5 V.
- Is the 74HCT540D compatible with TTL outputs?
Yes, the 74HCT540D is compatible with TTL outputs, with high-level input voltage (VIH) of 2.0 V (min) and low-level input voltage (VIL) of 0.8 V (max).
- What type of protection does the 74HCT540D have against static discharge?
The 74HCT540D has protection circuits against static discharge or transient excess voltage on all inputs.
- How do the 3-state outputs of the 74HCT540D work?
The outputs of the 74HCT540D can be set to a high-impedance state when either G1 or G2 is high.
- What is the quiescent supply current of the 74HCT540D?
The quiescent supply current (ICC) of the 74HCT540D is 4.0 µA (max) at Ta = 25°C.
- In what package is the 74HCT540D available?
The 74HCT540D is available in a SOIC20 package.
- Can the 74HCT540D be used in mixed logic systems?
Yes, the 74HCT540D can be used in mixed logic systems due to its compatibility with LSTTL, NMOS, and CMOS logic levels.
- What is the significance of balanced propagation delays in the 74HCT540D?
The balanced propagation delays (tPLH ≈ tPHL) ensure that the rise and fall times of the output signals are approximately equal, which is important for maintaining signal integrity in high-speed digital systems.
