I just breadboarded a power supply using an OnSemi LM317BT and OnSemi LM337T.
The 317 datasheet has the regular 0.1uF cap on the input "*Cin is required if regulator is located an appreciable distance from power supply filter."
I used a little round ceramic 104.
BUT the 337 datasheet says "*Cin is required if regulator is located more than 4 inches from power supply filter.
*A 1.0uF solid tantalum or 10uF aluminum electrolytic is recommended."
I used a 10uF electrolytic
You would assume that On Semiconductor manufactures the positive and negative regulators almost exactly the same way and that they would recommend the same input capacitor for both of them.
What would be the reason for the difference in recommendations for the 317 and 337?
The 317 datasheet has the regular 0.1uF cap on the input "*Cin is required if regulator is located an appreciable distance from power supply filter."
I used a little round ceramic 104.
BUT the 337 datasheet says "*Cin is required if regulator is located more than 4 inches from power supply filter.
*A 1.0uF solid tantalum or 10uF aluminum electrolytic is recommended."
I used a 10uF electrolytic
You would assume that On Semiconductor manufactures the positive and negative regulators almost exactly the same way and that they would recommend the same input capacitor for both of them.
What would be the reason for the difference in recommendations for the 317 and 337?