TDK-Lambda DC-DC Converters

Isolated DC-DC converters provide galvanic isolation between input and output, breaking ground loops and providing safety isolation. Use isolated converters when: Connecting to external equipment with different ground potentials

Safety requirements mandate isolation (medical, industrial)

Breaking ground loops in sensitive analog circuits

Creating floating outputs for multi-polarity supplies. Non-isolated converters (buck, boost, buck-boost) are simpler, smaller, and more efficient. Use them when: Input and output share a common ground

Cost and size are critical

Efficiency is the highest priority

No safety isolation is required. TDK-Lambda offers both types to suit various application requirements.

Select isolated converters for safety-critical applications or ground loop elimination, non-isolated for cost-sensitive common-ground applications.

TDK-Lambda DC-DC converters achieve high efficiency through synchronous rectification and optimized magnetic designs. Typical efficiencies range from 85% to 93% depending on the series and operating conditions. Higher output voltage ratios (e.g., 48V to 5V) generally achieve better efficiency than large step-down ratios (e.g., 24V to 3.3V). Efficiency also varies with load - most converters achieve peak efficiency at 50-100% load and decrease at very light loads. The CCG series typically achieves 88-92% efficiency, while the higher power PHV series reaches 90-93%. High efficiency reduces heat generation, allowing smaller thermal management solutions and improving overall system reliability.

For thermally constrained applications, select converters with highest efficiency and verify efficiency at your actual operating load.

Isolation voltage selection depends on your application requirements: Basic isolation (1000-1500V) is suitable for breaking ground loops and providing functional isolation in industrial equipment

Reinforced isolation (3000V) is required for medical equipment and safety-critical applications where operator protection is needed

Working voltage ratings must also be considered - the continuous voltage that can be applied across the isolation barrier. For medical applications, IEC 60601-1 requires 2xMOPP (Means of Patient Protection) which typically translates to 4000V isolation test voltage. For industrial automation, 1500V to 2000V is typically sufficient. Always verify the specific requirements of your application safety standards.

For medical or safety-critical applications, select converters with 3000V or higher isolation. For industrial ground loop breaking, 1500V is typically adequate.

Many TDK-Lambda DC-DC converters support parallel operation for increased output current or redundancy. There are several approaches: Passive droop sharing where converters with similar output voltages naturally share current based on internal resistance

Active current sharing using dedicated control pins for precise load balancing

External OR-ing diodes for redundancy applications to prevent back-feeding. When paralleling converters, ensure all units have matched output voltages and adequate thermal management. Not all converters support parallel operation - check the datasheet for 'Parallel Operation' specifications. For high-reliability applications, consider using N+1 redundancy with external OR-ing diodes.

For parallel operation, select converters specifically designed for current sharing and follow TDK-Lambda application notes for proper implementation.

TDK-Lambda DC-DC converters include comprehensive protection features: Input undervoltage lockout (UVLO) prevents operation when input voltage is too low

Output overcurrent protection (OCP) limits current during overload or short circuit conditions

Output overvoltage protection (OVP) prevents damage to sensitive loads

Overtemperature protection (OTP) shuts down the converter if internal temperature exceeds safe limits

Short circuit protection allows continuous operation into a short with automatic recovery. Many converters also feature remote on/off control and output voltage trim. These protection features ensure reliable operation and protect both the converter and the load from damage.

Review the specific protection features in the datasheet to ensure they meet your application's safety and reliability requirements.