Class II ceramic characterisation

DC bias droop → reference library match

Compares a measured droop against reference C-DC-bias curves at the same case, value and absolute bias voltage, and reports which ratings remain consistent.

Reading

C at 0 V

C under bias

Bias (V)

Case

Label

Match tolerance

6 pt

A rating stays in the candidate list if the reference band at your bias comes within this many percentage points of your reading.

Fixture offset

4.5 pt

Subtracted from every reading before matching. Calibrated on a known 0805 0.1 µF X7R 100 V part: 47.2% measured at 50 V and 73.1% at 90 V, against reference bands of 36.2–42.4% and 64.5–68.9% — a constant +4.5 pt. Most likely AC drive level above the reference 1.0 Vrms. Set to 0 to see raw readings.

DC bias fixture

Bias tee schematic: a 1000 megohm resistor U1 feeds DC bias from a 0 to 100 volt supply to the DUT, with a 100 microfarad blocking capacitor C1 and a 1 kilohm bleed resistor R1 on the return rail, a times-100 voltmeter reading bias across the part, and an LCR meter on the right.

Bias tee. U1 injects DC while presenting a high impedance to the measurement; C1 blocks that DC from the LCR meter's terminal. R1 bleeds the DUT down when the supply is lowered. The ×100 voltmeter reads bias directly across the part — the drop across U1 means the supply setting is not the DUT voltage.

bold band = candidatefaint = ruled outdashed = X5R your reading

Sample log — 0 parts

#	Label	Case	0 V	Bias	V	ΔC	Reference family	Dielectric	Consistent ratings