Important NoteThis entire repo was AI created - including all of the data within. The intent was to A) help me with my personal electronics inventory; and B) see how I could use AI to make that process a bit easier. DO NOT TRUST!
Crystals, Oscillators & Timing Components
Overview
This collection contains various timing components essential for providing accurate clock signals and frequency references in electronic circuits. These components are fundamental for microcontroller operation, real-time clocks, communication systems, and any application requiring precise timing.
Available Components and Locations
Bin 25 - Timing Components (Cabinet 2)
| Component | Part Number | Frequency | Package | Quantity | Applications |
|---|---|---|---|---|---|
| Watch Crystal | AB38T-32.768KHZ | 32.768kHz | Cylindrical Can | 8 | RTC, timekeeping |
| MHz Crystal | MP080A | 8MHz | HC-49/U | 3 | Microcontrollers |
| Voltage Regulator | L78L05ABZ-TR | N/A | TO-92 | 25 | Power supply |
| SMD Crystal | ECS-200-20-3X-TR | 20MHz | HC-49/US | 10 | High-speed digital |
| Through-Hole Crystals | Generic | 16MHz | HC-49 | 10 | Arduino, MCU |
Technical Specifications
AB38T-32.768KHZ Watch Crystal
Electrical Characteristics
- Frequency: 32.768kHz (2^15 Hz)
- Frequency Tolerance: ±20ppm
- Load Capacitance: 12.5pF
- ESR: 30kΩ maximum
- Operating Mode: Fundamental
- Operating Temperature: -10°C to +60°C
Physical Specifications
- Package: Cylindrical Can, Radial
- Dimensions: 3.20mm diameter × 8.30mm length
- Height Seated: 8.30mm maximum
- Mounting: Through-hole radial leads
- Lead Spacing: Standard 2.54mm (0.1”)
Key Features
- Ultra-Low Frequency: Perfect for timekeeping applications
- Low Power: Minimal current consumption
- High Accuracy: ±20ppm tolerance for precise timing
- Standard Package: Industry-standard cylindrical can
- Long Life: Excellent long-term stability
Applications
- Real-Time Clocks: RTC modules and timekeeping circuits
- Microcontroller Timing: 32kHz oscillator for low-power MCUs
- Watch Circuits: Digital watch and clock applications
- Timer Circuits: Precision timing and countdown applications
- Sleep Mode Timing: Wake-up timing for low-power systems
MP080A 8MHz Crystal
Electrical Characteristics
- Frequency: 8MHz
- Frequency Tolerance: ±30ppm
- Frequency Stability: ±50ppm
- Load Capacitance: 20pF
- ESR: 35Ω maximum
- Operating Mode: Fundamental
- Operating Temperature: -20°C to +70°C
Physical Specifications
- Package: HC-49/U
- Dimensions: 10.85mm × 3.80mm
- Height Seated: 13.46mm maximum
- Mounting: Through-hole
- Lead Spacing: Standard 0.2” (5.08mm)
Key Features
- Medium Frequency: Suitable for many microcontroller applications
- Low ESR: Good for oscillator circuits
- Standard Package: Industry-standard HC-49/U
- Wide Temperature Range: -20°C to +70°C operation
- Fundamental Mode: Clean sine wave output
Applications
- Microcontrollers: Clock source for 8-bit and 16-bit MCUs
- Digital Circuits: System clock for digital logic
- Communication: UART, SPI timing reference
- Timer Circuits: Precision timing applications
- Frequency Synthesis: Base frequency for PLLs
ECS-200-20-3X-TR 20MHz SMD Crystal
Electrical Characteristics
- Frequency: 20MHz
- Frequency Tolerance: ±30ppm
- Frequency Stability: ±50ppm
- Load Capacitance: 20pF
- ESR: 50Ω maximum
- Operating Mode: Fundamental
- Operating Temperature: -10°C to +70°C
Physical Specifications
- Package: HC-49/US Surface Mount
- Dimensions: 7.00mm × 4.10mm
- Height: 2.30mm maximum
- Mounting: Surface mount
- Termination: SMD pads
Key Features
- High Frequency: Suitable for high-speed digital applications
- Surface Mount: Compact SMD package
- Low Profile: 2.30mm height for space-constrained designs
- Good Stability: ±50ppm frequency stability
- Industry Standard: HC-49/US package format
Applications
- High-Speed MCUs: Clock source for 32-bit microcontrollers
- Digital Signal Processing: DSP and FPGA clock generation
- Communication Systems: High-speed serial communication
- USB Applications: USB clock generation (20MHz base)
- Video Applications: Video timing and synchronization
Generic 16MHz Through-Hole Crystals
Electrical Characteristics
- Frequency: 16MHz
- Frequency Tolerance: ±30ppm (typical)
- Load Capacitance: 18-22pF (typical)
- ESR: 50Ω maximum (typical)
- Operating Mode: Fundamental
- Operating Temperature: -20°C to +70°C (typical)
Physical Specifications
- Package: HC-49 Through-hole
- Dimensions: Standard HC-49 footprint
- Height: Varies by manufacturer
- Mounting: Through-hole
- Lead Spacing: 0.2” (5.08mm)
Key Features
- Popular Frequency: Common microcontroller frequency
- Arduino Compatible: Standard frequency for Arduino boards
- Through-Hole: Easy prototyping and breadboard use
- Cost Effective: Economical for hobby and educational use
- Wide Availability: Common frequency with multiple sources
Applications
- Arduino Projects: Clock source for Arduino Uno and compatible
- AVR Microcontrollers: ATmega328P and similar MCUs
- PIC Microcontrollers: 16MHz PIC microcontroller applications
- Prototyping: Breadboard and development board use
- Educational: Learning and training applications
Crystal Oscillator Design Guidelines
Load Capacitance Calculation
The load capacitance seen by the crystal should match its specified load capacitance:
CL = (C1 × C2) / (C1 + C2) + Cstray
Where:
- CL = Crystal load capacitance
- C1, C2 = External load capacitors
- Cstray = Stray capacitance (typically 2-5pF)
Typical Load Capacitor Values
- For 12.5pF crystals: Use 22pF capacitors
- For 18pF crystals: Use 33pF capacitors
- For 20pF crystals: Use 36pF capacitors
- For 22pF crystals: Use 39pF capacitors
PCB Layout Guidelines
- Keep traces short: Minimize trace length between crystal and IC
- Ground plane: Provide solid ground plane under crystal
- Avoid routing: Don’t route signals under or near crystal
- Shielding: Consider ground guard rings for sensitive applications
- Component placement: Keep switching circuits away from crystal
Drive Level Considerations
- Maximum drive: Don’t exceed crystal’s maximum drive level
- Minimum drive: Ensure sufficient drive for reliable oscillation
- Power consumption: Higher drive = higher power consumption
- Aging: Excessive drive can accelerate crystal aging
- Startup: Ensure adequate drive for reliable startup
Oscillator Circuit Design
Pierce Oscillator Configuration
Most common configuration for microcontroller crystals:
- Crystal between MCU oscillator pins
- Two load capacitors to ground
- Optional series resistor for drive level control
- Optional parallel resistor for bias (high-frequency crystals)
Colpitts Oscillator Configuration
Alternative configuration for discrete designs:
- Crystal in feedback path of amplifier
- Capacitive voltage divider for feedback
- Inductor for frequency tuning (if required)
- Buffer amplifier for output isolation
Clock Distribution
- Single source: Use one crystal with clock distribution
- Buffer amplifiers: Isolate crystal from loads
- Clock trees: Distribute clock to multiple circuits
- Skew management: Minimize clock skew in synchronous systems
- EMI considerations: Manage electromagnetic interference
Frequency Selection Guidelines
Microcontroller Applications
- 8MHz: Good for low-power applications, simple timing
- 16MHz: Standard for Arduino, AVR microcontrollers
- 20MHz: High-performance applications, fast processing
- 32MHz: High-speed ARM Cortex-M applications
Communication Applications
- 32.768kHz: RTC, low-power wake-up timing
- 1.8432MHz: UART baud rate generation (legacy)
- 3.6864MHz: UART baud rate generation
- 14.7456MHz: Multiple UART baud rates
Special Applications
- 27MHz: RC hobby applications, wireless
- 25MHz: Ethernet applications
- 50MHz: High-speed digital applications
- 100MHz: Very high-speed applications
Testing and Verification
Oscillation Testing
- Startup time: Measure time to stable oscillation
- Frequency accuracy: Verify frequency within tolerance
- Amplitude: Check oscillation amplitude
- Stability: Monitor frequency stability over time
- Temperature: Test over operating temperature range
Drive Level Testing
- Power measurement: Measure crystal power dissipation
- Current measurement: Monitor oscillator current
- Voltage measurement: Check oscillation amplitude
- Distortion: Verify clean sine wave output
- Harmonics: Check for unwanted harmonic content
EMI Testing
- Radiated emissions: Test for electromagnetic radiation
- Conducted emissions: Test for conducted interference
- Susceptibility: Test immunity to external interference
- Shielding effectiveness: Verify shielding performance
- Grounding: Check ground integrity
Troubleshooting
Common Issues
- No oscillation: Check connections, load capacitors, drive level
- Intermittent oscillation: Check solder joints, mechanical stress
- Wrong frequency: Verify crystal marking, load capacitance
- Poor stability: Check temperature, power supply, layout
- High current: Check for excessive drive level
Oscillation Failures
- Insufficient drive: Increase drive level or reduce load
- Excessive load: Reduce load capacitance or circuit loading
- Poor layout: Improve PCB layout and grounding
- Contamination: Clean crystal and circuit board
- Mechanical damage: Replace damaged crystal
Frequency Issues
- Load capacitance: Adjust load capacitors for correct frequency
- Temperature drift: Use temperature-compensated crystal
- Aging: Replace old crystals showing frequency drift
- Power supply: Stabilize power supply voltage
- Layout: Improve circuit layout and shielding
Storage and Handling
Storage Conditions
- Temperature: Store at room temperature
- Humidity: Low humidity environment preferred
- Mechanical: Protect from shock and vibration
- Contamination: Keep clean and protected
- Organization: Sort by frequency and package type
Handling Guidelines
- ESD Protection: Use ESD precautions during handling
- Mechanical Care: Avoid dropping or mechanical shock
- Lead Forming: Be careful when forming leads
- Soldering: Use appropriate soldering temperature and time
- Cleaning: Clean with appropriate solvents if needed
Package Contents
- Multiple crystal frequencies and package types
- Various load capacitances and specifications
- Both through-hole and surface mount options
- Suitable for wide range of timing applications
Important Notes
- Frequency Accuracy: Verify frequency requirements for application
- Load Capacitance: Match crystal load capacitance requirements
- Drive Level: Don’t exceed maximum drive level specifications
- Layout Critical: PCB layout significantly affects performance
- Temperature Effects: Consider temperature coefficient for precision applications
Advantages
- Precise Timing: Accurate frequency reference for digital systems
- Low Power: Minimal power consumption in oscillator circuits
- Stable: Excellent long-term frequency stability
- Standard Packages: Industry-standard package formats
- Wide Range: Multiple frequencies for various applications
Limitations
- Fragile: Mechanical shock can damage crystal structure
- Load Sensitive: Performance depends on proper load capacitance
- Layout Critical: Requires careful PCB layout for best performance
- Temperature Sensitive: Frequency varies with temperature
- Single Frequency: Each crystal provides only one frequency
Recommended Applications
- Microcontroller Clocks: System clock for MCU applications
- Real-Time Clocks: Timekeeping and calendar functions
- Communication Systems: Timing reference for serial communication
- Digital Signal Processing: Clock generation for DSP applications
- Prototyping: Development and educational projects