BDC688
BDC688: High-performance DC/DC converter
Technical specifications
preliminary
| Voltage range (high side) | 378-830 V |
| Voltage range (low side) | 200-400 V |
| Maximum current (low side) | 800 A |
| Voltage range (control circuit) | 9-18 V |
| Efficiency | >99.5 % |
| IP protection | IP67 |
| Communication interface | CAN |
| Cooling system | Water Cooling |
| Weight (without cooling water) | 41 kg |
The BDC688 is a boost converter for fuel cell and electric vehicle applications, converting lower-voltage inputs to higher-voltage outputs for 800 V systems. It features direct bus bar connections for efficient power transfer and includes advanced power distribution, real-time impedance spectroscopy, and robust safety features, making it ideal for commercial EVs and fuel cell buses.
Features
- Zero voltage switching for unmatched efficiency (up to 99.5%).
- Nominal low-side current of 800 A for high-power applications.
- Low current ripple, optimized for fuel cell and EV applications.
Power distribution & connectivity
- Supports multiple HV outputs for flexible energy distribution.
- 320 kW main output for primary power transfer.
- 50 kW output for compressors or auxiliary loads.
- 5 kW output for pumps or low-power applications.
- Direct bus bar connections facilitate a low-resistance interface with the fuel cell, reducing power losses and ensuring stable operation.
HFR impedance spectroscopy – fuel cell optimization
- Built-in electrochemical impedance spectroscopy (EIS) for real-time fuel cell health monitoring.
- 1kHz signal injection enables accurate impedance measurement and predictive maintenance.
- Improves fuel cell efficiency by detecting performance issues early.

