PRESETTABLE DIVIDE-BY-N COUNTER# Technical Documentation: HCC4018BF CMOS Presettable Divide-by-N Counter
## 1. Application Scenarios
### Typical Use Cases
The HCC4018BF is a monolithic integrated circuit fabricated in Metal Gate CMOS technology, functioning as a 5-stage Johnson counter with parallel data inputs for each stage. Its primary applications include:
- Frequency Division : Configurable as divide-by-2, 4, 6, 8, or 10 counters through appropriate feedback connections
- Sequence Generation : Producing non-overlapping timing sequences and control waveforms
- Data Synchronization : Synchronous parallel loading for preset initialization
- Waveform Shaping : Creating symmetrical square waves from clock inputs
### Industry Applications
- Industrial Control Systems : Timing and sequencing in PLCs, motor control circuits, and process automation
- Telecommunications : Frequency synthesizers and clock management in low-to-medium speed digital systems
- Consumer Electronics : Digital displays, appliance timers, and entertainment device controllers
- Automotive Electronics : Dashboard instrumentation and simple control sequencing
- Test & Measurement Equipment : Programmable counter functions in signal generators and frequency counters
### Practical Advantages and Limitations
Advantages:
- Low Power Consumption : Typical quiescent current of 1nA at 5V makes it suitable for battery-operated devices
- Wide Supply Voltage Range : 3V to 18V operation provides design flexibility
- High Noise Immunity : CMOS technology offers approximately 45% of supply voltage noise margin
- Synchronous Operation : All state changes occur on positive clock edges, minimizing timing uncertainties
- Buffered Outputs : Capable of driving two low-power TTL loads or one low-power Schottky TTL load
Limitations:
- Moderate Speed : Maximum clock frequency of 12MHz at 10V limits high-speed applications
- Limited Drive Capability : Requires buffer stages for driving heavy loads or transmission lines
- Static Sensitivity : CMOS device requires standard ESD precautions during handling
- Temperature Constraints : Commercial temperature range (0°C to +70°C) restricts extreme environment use
## 2. Design Considerations
### Common Design Pitfalls and Solutions
Pitfall 1: Clock Signal Integrity
- Problem : Ringing or slow edges on clock input causing double-counting or metastability
- Solution : Implement proper clock conditioning with Schmitt trigger (e.g., HCC40106) for noisy environments
Pitfall 2: Unused Input Handling
- Problem : Floating CMOS inputs causing excessive power consumption and erratic behavior
- Solution : Tie all unused inputs (JAM inputs, preset enable) to VDD or VSS through appropriate resistors
Pitfall 3: Power Supply Decoupling
- Problem : Switching noise coupling into supply lines causing false triggering
- Solution : Place 100nF ceramic capacitor within 10mm of VDD pin, with additional 10μF bulk capacitor
Pitfall 4: Output Loading
- Problem : Excessive capacitive loading causing slow rise times and increased power dissipation
- Solution : Limit load capacitance to 50pF maximum; use buffer stages for higher loads
### Compatibility Issues with Other Components
TTL Interface Considerations:
- When driving TTL inputs from HCC4018BF outputs, ensure:
- Supply voltage ≥ 5V for adequate output current
- Use pull-up resistors (1-10kΩ) on outputs for improved logic high levels
- Consider HCC4049 hex inverter as buffer for improved drive capability
Mixed CMOS Families:
- Compatible with 4000B series CMOS at any supply voltage
- For interfacing with 74HC series, ensure voltage levels match (both at same VDD)
- Avoid direct connection to 74LS series without proper
