10-Bit Buffer/Line Driver# Technical Documentation: 74F828SC 10-Bit Bus Interface Flip-Flop
Manufacturer : FAIRCHILD
Component Type : 10-Bit Bus Interface Flip-Flop with 3-STATE Outputs
Technology : FAST (Fairchild Advanced Schottky TTL)
## 1. Application Scenarios
### Typical Use Cases
The 74F828SC serves as a high-performance bus interface component in digital systems where reliable data transfer and temporary storage are critical. Primary applications include:
Data Buffering Systems
- Acts as intermediate storage between asynchronous systems
- Buffers data between processors and peripheral devices
- Maintains data integrity during bus contention scenarios
- Example: Between microprocessor and memory subsystems operating at different clock domains
Bus Isolation and Driving
- Provides electrical isolation between bus segments
- Drives heavily loaded backplanes with 64 mA output capability
- Prevents bus contention through 3-STATE output control
- Enables hot-swapping capabilities in modular systems
Pipeline Register Applications
- Implements pipeline stages in high-speed digital processing
- Synchronizes data flow in DSP and communication systems
- Maintains timing margins in clock-domain crossing circuits
### Industry Applications
Computing Systems
- Workstation and server backplane interfaces
- Memory controller data path buffering
- PCI/ISA bus interface logic
- Multi-processor communication bridges
Telecommunications Equipment
- Digital cross-connect systems
- Network switch fabric interfaces
- Telecom backplane drivers
- Signal processing pipeline registers
Industrial Control Systems
- PLC (Programmable Logic Controller) backplanes
- Motor control interface circuits
- Sensor data acquisition systems
- Real-time control system data paths
Test and Measurement Equipment
- Digital oscilloscope acquisition memory interfaces
- Logic analyzer input buffering
- ATE (Automatic Test Equipment) channel cards
### Practical Advantages and Limitations
Advantages:
- High-Speed Operation : 7.5 ns typical propagation delay enables operation up to 100 MHz
- Robust Drive Capability : 64 mA output current drives heavily loaded buses
- Bus-Friendly Architecture : 3-STATE outputs prevent bus contention
- Wide Operating Range : 4.5V to 5.5V supply voltage tolerance
- Low Power Consumption : 180 mA maximum ICC for power-sensitive applications
Limitations:
- TTL Compatibility : Requires level shifting for mixed 3.3V/5V systems
- Power Supply Sensitivity : Requires clean, well-regulated 5V supply with proper decoupling
- Heat Dissipation : May require thermal considerations in high-density layouts
- Legacy Technology : Being superseded by lower-voltage alternatives in new designs
## 2. Design Considerations
### Common Design Pitfalls and Solutions
Power Supply Decoupling
- Pitfall : Inadequate decoupling causing ground bounce and signal integrity issues
- Solution : Use 0.1 μF ceramic capacitors at each VCC pin, placed within 0.5 cm
- Additional : Bulk decoupling (10-100 μF) for every 5-10 devices on the board
Signal Integrity Management
- Pitfall : Ringing and overshoot on high-speed signals
- Solution : Implement series termination resistors (22-33Ω) near driver outputs
- Additional : Controlled impedance routing for critical clock and data lines
Thermal Management
- Pitfall : Excessive junction temperature affecting reliability
- Solution : Ensure adequate airflow and consider thermal vias in PCB layout
- Additional : Monitor power dissipation in high-frequency applications
### Compatibility Issues with Other Components
Voltage Level Compatibility
- TTL Systems : Direct compatibility with 5V TTL logic families
- CMOS Interfaces : May require pull-up resistors for
