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Part Number: SG-8002JC74.2444M PCC

Manufacturer: EPSON

Specifications:

• Frequency: 74.2444 MHz
• Package Type: PCC (Plastic Chip Carrier)
• Output Type: CMOS
• Supply Voltage: 3.3V
• Operating Temperature Range: -40°C to +85°C
• Frequency Stability: ±50 ppm
• Load Capacitance: 15 pF
• Aging: ±5 ppm per year (max)

Description:

The SG-8002JC74.2444M PCC is a CMOS-output crystal oscillator manufactured by EPSON. It provides a stable clock signal at 74.2444 MHz with low jitter and high reliability, suitable for various digital applications.

Features:

• Compact Size: PCC package for space-constrained designs
• Low Power Consumption: Optimized for 3.3V operation
• High Stability: ±50 ppm frequency tolerance
• Wide Temperature Range: Operates from -40°C to +85°C
• RoHS Compliant: Meets environmental standards

This oscillator is commonly used in telecommunications, networking, and embedded systems requiring precise timing.

# Technical Analysis of the SG-8002JC74.2444M PCC Crystal Oscillator

## Practical Application Scenarios

The SG-8002JC74.2444M PCC from EPSON is a high-precision surface-mount crystal oscillator (SPXO) designed for applications requiring stable frequency references. Key use cases include:

1. Telecommunications Equipment

• Used as a clock source in network switches, routers, and base stations due to its low jitter (typically <1 ps) and 74.2444 MHz output frequency, ensuring reliable data synchronization.

2. Industrial Automation Systems

• Provides timing for PLCs (Programmable Logic Controllers) and motor control units where frequency stability (±50 ppm) is critical for synchronized operations.

3. Consumer Electronics

• Integrated into high-end audio/video processing systems (e.g., HDMI transceivers) to minimize signal distortion.

4. Embedded Computing

• Serves as a reference clock for microcontrollers and FPGAs in automotive and IoT devices, where temperature stability (-20°C to +70°C) is essential.

## Common Design-Phase Pitfalls and Avoidance Strategies

1. Improper PCB Layout

• *Pitfall:* Placing the oscillator near noise sources (e.g., power supplies) can degrade signal integrity.
• *Solution:* Follow EPSON’s recommended layout guidelines—keep traces short, use ground planes, and avoid vias near the oscillator.

2. Incorrect Load Capacitance Matching

• *Pitfall:* Mismatched load capacitors (default: 10 pF) can cause frequency drift.
• *Solution:* Verify load capacitance using the formula:

\[

C_L = \frac{(C_1 \times C_2)}{(C_1 + C_2)} + C_{stray}

\]

where \(C_{stray}\) accounts for parasitic capacitance.

3. Thermal Stress Issues

• *Pitfall:* Excessive reflow temperatures (>260°C) may damage the oscillator.
• *Solution:* Adhere to IPC/JEDEC J-STD-020 reflow profiles and avoid prolonged exposure to high temperatures.

4. Power Supply Noise Coupling

• *Pitfall:* Ripple on the VCC line (3.3V typical) can introduce phase noise.
• *Solution:* Use low-ESR decoupling capacitors (0.1 µF ceramic + 1 µF tantalum) close to the power pin.

## Key Technical Considerations for Implementation

1. Frequency Stability

• The SG-8002JC74.2444M PCC offers ±50 ppm stability over its operating temperature range. For tighter tolerances, consider an oven-controlled oscillator (OCXO).

2. Start-Up Time

• Typical start-up time is 5 ms; ensure system reset sequences accommodate this delay.

3. Aging Effects

• Aging rate is ±5 ppm/year; long-term designs should account for gradual frequency drift.

4. EMI Mitigation

• Shield the oscillator if used in RF-sensitive environments to prevent interference.

By addressing these