UC3843: uc3843

Hi Valery,

Thanks for reaching out. The difference between UC3843 and UC3843A is:

"The UCx84xA family of control devices is a pin-for-pin compatible improved version of the UCx84x family. Providing the necessary features to control current mode or switched-mode power supplies, this family of devices has many improved features: startup current is less than 0.5mA, oscillator discharge is trimmed to 8.3mA, and during UVLO, the output stage can sink at least 10mA at less than 1.2V for VCC over 5V."

This information is given in the description section, in the first page of UC3943A datasheet: UCx84xA Current-Mode PWM Controller datasheet (Rev. H)

Please let me know if you have more questions. Else if you feel that I have answered your question, please click on "this resolved my issue" button.

Thank you.

Best,

Adhvaidh