While Digital Fault Recorders (DFRs) can detect transients in 17/20 μs at 60/50 Hz, transient recorders capture disturbances that can peak and decay well within a microsecond. This reference design demonstrates the capturing of transient inputs at up to 1 MHz for DFR and 25 MHz for transient tecorders. Both positive and negative transients (<=2-kV peak) can be captured with varying resolution based on application need (12-bit to 14-bit resolution) and within 10% accuracy using a differential amplifier driving a high-speed converter.
Features
- Transient recording from 10 MHz to 25 Mhz (> 166,000 samples/cycle)
- DFR of up to 1 MHz
- Differential amplifier front end to interface transient inputs to differential ADC
- Measurement range: capture input transient from 250-V to 2-kV peak, 1.2/50 us
- Measurement sensitivity (10% to 100% of input voltage range): ±20 V (resolution) for 2-kV peak
- Measurement accuracy (10% to 100% of input voltage range): < 10% for transient capture and < 1% for DFR
- Tested for surge immunity as per IEC61000-4-5 up to 4 kV with 42-Ω impedance