“Stacking the REF50xx for High-Voltage References” (PDF ... and then stacked ten of them for a 1000V reference. Leaving it for 24 hours to settle, they achieved a precision of +/- 2.5ppm ...

TDK Corporation has released the X1 capacitors of the EPCOS B3291xH/J4 series for power line filtering of EMI in demanding automotive and industrial applications with a rated AC voltage of up to 480V.