Fixed Inductors for Cellular Phone # Technical Documentation: 972AS330M Inductor
Manufacturer : TOKO
Component Type : Surface Mount Power Inductor
## 1. Application Scenarios
### Typical Use Cases
The 972AS330M is a 33µH shielded power inductor designed for high-frequency power conversion applications. Primary use cases include:
DC-DC Converters
- Buck/boost converter output filtering
- Voltage regulator modules (VRMs)
- Point-of-load (POL) converters
- Typical operating frequencies: 100kHz to 2MHz
Power Supply Filtering
- Switching power supply input/output filtering
- EMI/RFI noise suppression
- LC filter networks in power delivery systems
- Decoupling applications in high-speed digital circuits
### Industry Applications
Consumer Electronics
- Smartphones and tablets (power management ICs)
- Laptop computers (CPU/GPU power delivery)
- Gaming consoles and portable devices
- LED lighting drivers and controllers
Automotive Electronics
- Infotainment systems power supplies
- Advanced driver assistance systems (ADAS)
- Engine control units (ECU power conditioning)
- LED lighting drivers in automotive applications
Industrial Equipment
- Programmable logic controller (PLC) power systems
- Motor drive circuits
- Industrial automation power supplies
- Test and measurement equipment
Telecommunications
- Base station power systems
- Network equipment power distribution
- RF power amplifier bias circuits
- Data center server power supplies
### Practical Advantages and Limitations
Advantages:
- High Saturation Current : Capable of handling up to 1.2A without significant inductance drop
- Low DC Resistance : 0.65Ω typical, minimizing power losses
- Shielded Construction : Reduced electromagnetic interference (EMI)
- Thermal Stability : Maintains performance across -40°C to +125°C
- Compact Size : 7.3×6.6×4.5mm footprint suitable for space-constrained designs
Limitations:
- Current Handling : Maximum 1.2A limits use in high-power applications
- Frequency Range : Optimal performance up to 2MHz, not suitable for RF applications
- Self-Resonant Frequency : Approximately 8MHz, limiting high-frequency applications
- Thermal Considerations : Requires adequate PCB copper area for heat dissipation
## 2. Design Considerations
### Common Design Pitfalls and Solutions
Saturation Current Miscalculation
- Pitfall : Operating near maximum current causing inductance collapse
- Solution : Design for 70-80% of Isat maximum, implement current monitoring
Thermal Management Issues
- Pitfall : Overheating due to inadequate heat sinking
- Solution : Use thermal vias, ensure proper copper pour area (minimum 100mm²)
PCB Stress Problems
- Pitfall : Mechanical stress from board flexure affecting performance
- Solution : Maintain minimum 2mm clearance from board edges, avoid mounting near connectors
### Compatibility Issues
Semiconductor Compatibility
- Compatible with most switching regulators (TI, Analog Devices, Maxim)
- May require additional snubber circuits with fast-switching MOSFETs
- Check controller switching frequency compatibility (100kHz-2MHz optimal)
Capacitor Selection
- Pair with low-ESR ceramic capacitors for best performance
- Avoid using with high-ESR electrolytic capacitors in critical filter applications
- Recommended: X5R/X7R ceramics with voltage ratings 2× operating voltage
Layout Conflicts
- Maintain minimum 3mm clearance from high-frequency digital circuits
- Avoid placement near transformers or other magnetic components
- Keep away from crystal oscillators and clock circuits
### PCB Layout Recommendations
Power Routing
- Use wide, short traces for high-current paths (minimum 20mil width for
