1.0 A, Adjustable Output Voltage, Step-Down Switching Regulator # DO5022P104 Power Inductor Technical Documentation
## 1. Application Scenarios
### Typical Use Cases
The DO5022P104 is a 100µH shielded power inductor primarily employed in:
DC-DC Converter Applications
- Buck Converters : Functions as the output filter inductor in step-down configurations, storing energy during switch-on periods and releasing it during off periods
- Boost Converters : Serves as energy storage element in voltage step-up circuits
- Buck-Boost Converters : Provides stable inductance in variable output voltage applications
Power Supply Filtering
- Input Filtering : Suppresses electromagnetic interference (EMI) and high-frequency noise from power sources
- Output Filtering : Smooths output ripple current in switching power supplies
- LC Filter Networks : Forms resonant circuits with capacitors for noise suppression
### Industry Applications
Consumer Electronics
- Smartphones/Tablets : Power management ICs (PMICs) and voltage regulation modules
- Wearable Devices : Space-constrained applications requiring minimal EMI radiation
- Portable Audio Equipment : Audio amplifier power supplies and noise filtering
Automotive Systems
- Infotainment Systems : Power conditioning for display and audio subsystems
- ADAS Modules : Sensor power supplies requiring stable, low-noise operation
- Body Control Modules : Distributed power distribution networks
Industrial Equipment
- PLC Systems : Digital I/O module power isolation
- Motor Drives : Control circuit power supplies
- Test & Measurement : Precision analog circuit power conditioning
Telecommunications
- Network Equipment : Point-of-load converters for FPGAs and ASICs
- Base Stations : RF power amplifier bias supplies
### Practical Advantages and Limitations
Advantages
- High Current Handling : Rated for 0.29A saturation current, suitable for moderate power applications
- Shielded Construction : Minimizes electromagnetic interference to adjacent components
- Thermal Stability : Maintains inductance within ±20% across operating temperature range (-40°C to +125°C)
- Mechanical Robustness : Molded construction resists mechanical stress and vibration
- Low DCR : 3.65Ω maximum DC resistance minimizes power losses
Limitations
- Current Handling : Not suitable for high-current applications (>0.29A)
- Frequency Limitations : Performance degrades above self-resonant frequency (~10MHz typical)
- Saturation Characteristics : Inductance drops significantly near saturation current
- Size Constraints : 5.8mm × 5.2mm footprint may be large for ultra-compact designs
## 2. Design Considerations
### Common Design Pitfalls and Solutions
Current Saturation Issues
- Pitfall : Operating near saturation current causes inductance collapse and efficiency degradation
- Solution : Design with 20-30% margin below Isat (limit to ~0.23A maximum operating current)
- Detection : Monitor output ripple voltage increase as saturation indicator
Thermal Management
- Pitfall : Excessive core losses at high frequencies causing temperature rise
- Solution : Ensure adequate airflow and consider thermal vias in PCB layout
- Monitoring : Use thermal imaging during validation to identify hot spots
Resonance Problems
- Pitfall : Operating near self-resonant frequency causing unpredictable behavior
- Solution : Keep switching frequency below 1/3 of SRF for stable operation
- Compensation : Include damping networks if operation near resonance is unavoidable
### Compatibility Issues with Other Components
Semiconductor Interactions
- Switching FETs : Ensure fast switching transitions to minimize switching losses
- Controller ICs : Verify compatibility with inductor's DCR for current sensing applications
- Diodes : Match reverse recovery characteristics with inductor current waveform
Capacitor Selection
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