ZHCSDP1E January 2009 – February 2019 UC1842A-SP , UC1844A-SP
PRODUCTION DATA.
When using a low-value ceramic input filter capacitor, locate it as close as possible to the VIN pin of the IC. This eliminates as much trace inductance effects as possible and gives the internal IC rail a cleaner voltage supply. Some designs require the use of a feed-forward capacitor connected from the output to the feedback pin as well, usually for stability reasons. In this case, it should also be positioned as close as possible to the IC. Using surface mount capacitors also reduces lead length and lessens the chance of noise coupling into the effective antenna created by through-hole components.