SURFACE MOUNT GLASS PASSIVATED JUNCTION FAST EFFICIENT RECTIFIER# EGL34G Silicon PIN Photodiode Technical Documentation
*Manufacturer: VISHAY*
## 1. Application Scenarios
### Typical Use Cases
The EGL34G is a high-speed silicon PIN photodiode optimized for visible to near-infrared light detection (350-1100 nm wavelength range). Its primary applications include:
Optical Communication Systems
- Fiber optic receivers in 850 nm multimode systems
- Data transmission in LAN/WAN applications
- Optical interconnects for high-speed computing
- Advantage : Fast response time (typically 1 ns) enables data rates up to 1 Gbps
- Limitation : Requires precise optical alignment for optimal performance
Industrial Sensing
- Position detection in automated machinery
- Object presence sensing in conveyor systems
- Barcode scanning and decoding
- Advantage : High sensitivity across visible spectrum
- Limitation : Susceptible to ambient light interference without proper filtering
Medical Instrumentation
- Pulse oximetry systems
- Blood analysis equipment
- Non-invasive diagnostic devices
- Advantage : Excellent linearity in photocurrent response
- Limitation : Requires medical-grade EMI shielding in sensitive applications
### Industry Applications
- Telecommunications : Optical transceivers, network switches
- Automotive : Rain sensors, ambient light detection
- Consumer Electronics : Remote control receivers, proximity sensors
- Industrial Automation : Encoder systems, safety curtains
### Practical Advantages and Limitations
Advantages:
- Wide spectral response (350-1100 nm)
- Low dark current (typically 2 nA at 5V reverse bias)
- High quantum efficiency (0.85 A/W at 850 nm)
- Small package size (2.65 mm diameter)
- RoHS compliant
Limitations:
- Temperature-dependent responsivity (-0.2%/°C typical)
- Limited reverse voltage tolerance (30V maximum)
- Requires anti-reflective coating for optimal performance
- Sensitive to electrostatic discharge (ESD)
## 2. Design Considerations
### Common Design Pitfalls and Solutions
Pitfall 1: Inadequate Bias Voltage
- Issue : Operating without sufficient reverse bias reduces response speed
- Solution : Maintain 5-12V reverse bias for optimal performance
Pitfall 2: Poor Optical Coupling
- Issue : Signal loss due to misalignment with light source
- Solution : Use precision mechanical mounts and optical lenses
Pitfall 3: Ambient Light Interference
- Issue : DC offset and noise from environmental lighting
- Solution : Implement optical filters and AC-coupled amplification
### Compatibility Issues
Amplifier Selection
- Requires transimpedance amplifiers with low input bias current (<1 nA)
- Compatible with OPAG57, LTC6268 for high-speed applications
- Avoid amplifiers with high input capacitance (>2 pF)
Power Supply Requirements
- Stable low-noise DC supply essential
- Ripple voltage <10 mV peak-to-peak
- Decoupling capacitors (100 nF ceramic + 10 μF tantalum) recommended
### PCB Layout Recommendations
Signal Integrity
- Keep photodiode close to amplifier input (trace length <10 mm)
- Use ground plane beneath signal traces
- Shield sensitive analog sections from digital noise
Thermal Management
- Avoid placement near heat-generating components
- Maintain ambient temperature below 85°C
- Provide adequate ventilation if using high-power illumination
ESD Protection
- Implement TVS diodes on bias supply lines
- Use ESD-safe handling during assembly
- Include discharge paths for accumulated charge
## 3. Technical Specifications
### Key Parameters
| Parameter | Value | Conditions |
|-----------|-------|------------|
| Active Area | 7.5 mm² | - |
| Peak W
