NSi6601
NSi6601 is a single-channel isolated gate driver with 4A/6A output, desaturation detection, and soft turn-off for IGBT protection.
Product Overview
Description
The NSi6601 is a high-reliability single-channel isolated gate driver featuring integrated desaturation detection and soft turn-off protection. With 4A source and 6A sink current, it provides robust drive capability for IGBTs up to 300A.
The integrated desaturation detection monitors the IGBT collector-emitter voltage during conduction and initiates soft turn-off if overcurrent is detected. This protects the IGBT from damage during short-circuit conditions while minimizing voltage transients.
With 5kVrms reinforced isolation, >150kV/us CMTI, and comprehensive protection features, the NSi6601 is ideal for industrial motor drives, inverters, and power supplies requiring high reliability.
Product Series
NSi
Primary Application
Industrial motor drives
Key Features
- 4A/6A peak output current
- Integrated desaturation detection
- Soft turn-off for fault protection
- 5kVrms reinforced isolation
- >150kV/us CMTI
- Active Miller clamp
- UVLO protection on all supplies
- Fault indication output
Specifications
| Peak Output Current | 4A source/6A sink |
|---|---|
| Isolation Voltage | 5kVrms (reinforced) |
| Working Voltage | 1.5kVrms |
| CMTI | >150kV/us |
| Propagation Delay | 65ns typical |
| Desaturation Threshold | 7V typical |
| Soft Turn-off Time | 2.5us typical |
| Operating Temperature | -40°C to +125°C |
| Package | SOIC-16 |
| Certification | UL1577, IEC 60747-5-5 |
| Voltage Rating | 5kVrms |
| Current Rating | 6A |
| Temperature Range | -40°C to +125°C |
Applications
Industrial motor drives
Motor drive and control systems
IGBT inverters
Electronic system design
Welding equipment
Electronic system design
UPS systems
Electronic system design
Induction heating
Electronic system design
Power factor correction
Electronic system design
FAE Expert Insights
"The NSi6601 is my top choice for IGBT applications requiring short-circuit protection. The integrated desaturation detection eliminates the need for external protection circuits, saving BOM cost and PCB space. The soft turn-off feature is critical - I've seen hard turn-off during faults cause voltage spikes that damage IGBTs. The 2.5us soft turn-off time in NSi6601 limits voltage overshoot while still clearing faults quickly. The 6A sink current ensures fast turn-off even with large IGBTs. For motor drives and inverters where reliability is paramount, the NSi6601 provides comprehensive protection in a single IC."
Excellent protection features for high-reliability IGBT applications
— Senior Applications Engineer, BeiLuo
Frequently Asked Questions
How does the desaturation detection circuit work?
The desaturation detection circuit monitors the IGBT collector-emitter voltage during the on-state to detect overcurrent conditions. When the IGBT is on, if the current exceeds the rated value, the VCE(sat) increases above normal levels. The desaturation circuit compares the VCE to an internal threshold (typically 7V). If VCE exceeds this threshold for longer than the blanking time (typically 300ns), a fault is detected. The driver then initiates a soft turn-off sequence, gradually reducing the gate voltage over 2.5us to prevent high di/dt and voltage spikes. The fault is reported via the FLT output pin, allowing the controller to take appropriate action such as disabling all phases.
Use NSi6601 for IGBT applications requiring short-circuit protection. Adjust blanking time based on your IGBT's switching characteristics.
What is the difference between soft turn-off and normal turn-off?
Soft turn-off and normal turn-off differ in gate discharge rate: Normal turn-off uses the full sink current (6A for NSi6601) to rapidly discharge the gate, turning off the IGBT in typically 100-200ns. This is used for normal switching to minimize switching losses. Soft turn-off uses a controlled current source to slowly discharge the gate over 2.5us. This is used during fault conditions to limit di/dt and prevent voltage overshoots. During a short-circuit fault, the IGBT is carrying very high current. If turned off rapidly (hard turn-off), the high di/dt combined with circuit inductance creates large voltage spikes (V = L × di/dt) that can exceed the IGBT's voltage rating and cause failure. Soft turn-off limits di/dt, keeping voltage within safe limits while still clearing the fault.
Soft turn-off is automatically activated during desaturation faults. No external configuration is required.