Power Inductors # Technical Documentation: CDRH4D18CNP1R1P Power Inductor
Manufacturer : SUMIDA
Component Type : Shielded Drum Core Power Inductor
## 1. Application Scenarios
### Typical Use Cases
The CDRH4D18CNP1R1P is specifically designed for high-frequency power conversion applications where space constraints and EMI suppression are critical concerns. Typical implementations include:
- DC-DC Buck Converters : Operating in switching frequencies from 500 kHz to 2 MHz, particularly in step-down configurations where 1.1 μH inductance provides optimal ripple current filtering
- Voltage Regulator Modules (VRMs) : Supporting CPU core voltage regulation in computing systems requiring fast transient response
- Load Point Converters : Distributed power architecture systems where local power conditioning is necessary
### Industry Applications
Consumer Electronics
- Smartphones and tablets for power management IC (PMIC) output filtering
- Wearable devices where miniature footprint (4.0×4.0×1.8mm) is essential
- Portable gaming consoles and handheld medical devices
Computing Systems
- Motherboard VRM circuits for processors and memory
- SSD power conditioning circuits
- Network switch and router power supplies
Automotive Electronics
- Infotainment system power supplies (non-safety critical)
- ADAS sensor power conditioning
- Telematics control units
Industrial Equipment
- PLC I/O module power isolation
- Sensor interface power circuits
- Industrial communication module power supplies
### Practical Advantages and Limitations
Advantages:
- Excellent EMI Performance : Magnetic shielding reduces radiated emissions by 40-50% compared to unshielded counterparts
- High Saturation Current : 2.8A saturation current supports high transient load conditions
- Low DC Resistance : 90mΩ typical DCR minimizes conduction losses
- Thermal Stability : Operating temperature range of -40°C to +125°C ensures reliability in harsh environments
- Automated Assembly Compatibility : Standard reel packaging supports high-volume manufacturing
Limitations:
- Limited Current Handling : Maximum RMS current of 2.1A may require paralleling for higher power applications
- Frequency Dependency : Performance degrades above 3MHz due to core material characteristics
- Cost Premium : 15-20% higher cost compared to unshielded alternatives
- Size Constraints : Fixed 1.1μH value may not suit all application requirements
## 2. Design Considerations
### Common Design Pitfalls and Solutions
Pitfall 1: Inadequate Current Margin
- Problem : Designing too close to saturation current (2.8A) without considering temperature derating
- Solution : Maintain 20-30% design margin; derate current by 15% at 85°C ambient temperature
Pitfall 2: Improper Thermal Management
- Problem : Overheating due to poor airflow or adjacent heat sources
- Solution : Implement thermal vias in PCB, maintain minimum 2mm clearance from heat-generating components
Pitfall 3: Resonance Issues
- Problem : Unwanted resonance with parasitic capacitances at high frequencies
- Solution : Include damping networks or select alternative values for frequencies above 2MHz
### Compatibility Issues with Other Components
Switching Regulators
- Compatible : Most synchronous buck controllers (TPS62xxx, MPQxx series)
- Incompatible : Requires evaluation with hysteretic controllers due to variable frequency operation
Capacitors
- Optimal : Ceramic MLCCs (X7R, X5R) for low ESR and stable performance
- Caution : Avoid large tantalum capacitors in parallel without proper ESR consideration
Semiconductors
- MOSFETs : Compatible with
