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Input Buffer Gain

If you are hunting for a \(4.7 \mu F\) film capacitor online or in a parts bin, it will typically be labeled something like 475J63 or 475K100.

Here is how the math breaks down:

  • 47 (The Base): Your starting significant digits.
  • 5 (The Multiplier): This means "add 5 zeros" to the base in picofarads (pF). So, 47 + 00000 = \(4,700,000 \text{ pF}\).
  • The Conversion: \(4,700,000 \text{ pF}\) divided by 1,000,000 gives you exactly \(4.7 \mu F\).
  • The Letters/Letters (Tolerance and Voltage): "J" means \(\pm 5\)% tolerance (while "K" is \(\pm 10\)% ). The number at the end (like 63, 100, or 250) is the max DC voltage rating.

Just as a quick heads-up: if you order a 475J100 box film capacitor, prepare for it to be physically massive! It will easily be the largest component on this stage of your circuit.