High Temperature 150°C Series TRIAC # CHTA12600 Solid State Relay Technical Documentation
*Manufacturer: CRYDOM*
## 1. Application Scenarios
### Typical Use Cases
The CHTA12600 is a 25A, 600V optically isolated solid state relay designed for high-power AC switching applications. Typical implementations include:
Industrial Control Systems
- Motor control circuits for industrial machinery
- Heating element control in industrial ovens and furnaces
- Solenoid and contactor actuation in automated systems
- Process control equipment requiring reliable AC switching
Commercial Applications
- HVAC system controls for commercial buildings
- Commercial lighting control systems
- Power distribution unit (PDU) switching
- Uninterruptible power supply (UPS) bypass circuits
Specialized Implementations
- Medical equipment power control
- Test and measurement equipment switching
- Renewable energy system controls
- Industrial safety system interfaces
### Industry Applications
- Manufacturing : Production line automation, robotic control interfaces
- Energy Management : Smart grid applications, load shedding systems
- Building Automation : Smart building control systems, energy management
- Transportation : Railway signaling systems, electric vehicle charging stations
### Practical Advantages
- High Reliability : No moving parts, eliminating mechanical wear
- Fast Switching : Typical turn-on time of 1ms, turn-off time of 1/2 cycle
- Long Lifespan : >10^8 operations at rated load
- Noise-Free Operation : Zero voltage turn-on reduces EMI
- Optical Isolation : 4000V RMS input-output isolation
- Compact Design : Industry-standard package (DIN 41617)
### Limitations
- Heat Dissipation : Requires proper heatsinking at full load current
- Voltage Drop : Typical 1.6V forward voltage reduces efficiency
- Leakage Current : <5mA when in off-state
- Minimum Load : May not switch properly with very low loads (<100mA)
- Cost Consideration : Higher initial cost compared to electromechanical relays
## 2. Design Considerations
### Common Design Pitfalls and Solutions
Thermal Management Issues
- Pitfall : Inadequate heatsinking leading to thermal shutdown or premature failure
- Solution : Calculate thermal resistance requirements using:
```
Tj = Ta + (P × Rθj-a)
Where P = I² × Rds(on) + switching losses
```
Ensure junction temperature remains below 110°C
Snubber Circuit Omission
- Pitfall : Voltage transients causing false triggering or device damage
- Solution : Implement RC snubber circuit (typically 100Ω + 0.1µF) across output
Insufficient Input Drive
- Pitfall : Incomplete turn-on leading to excessive heating
- Solution : Provide minimum 10mA input current with proper voltage (3-32V DC)
### Compatibility Issues
Microcontroller Interfaces
- Issue : Insufficient drive capability from microcontroller GPIO
- Resolution : Use buffer IC (e.g., ULN2003) or transistor driver stage
Power Supply Considerations
- Issue : Inrush current during turn-on causing voltage dips
- Resolution : Implement soft-start circuits or oversize power supply
EMI/RFI Concerns
- Issue : Switching noise affecting sensitive analog circuits
- Resolution : Implement proper filtering and physical separation on PCB
### PCB Layout Recommendations
Thermal Design
- Use 2oz copper thickness for power traces
- Provide adequate copper area for heatsinking (minimum 25cm²)
- Position away from heat-sensitive components
High-Current Routing
- Trace width: Minimum 3mm per 10A of current
- Use multiple vias for layer transitions in high-current paths
- Keep output traces as short as possible
