Vout = Vref * (1 + R1/R2) where R1 is a resistor from the output to the ADJ pin and R2 is from the ADJ pin to ground.
Vref is 1.2 volts the Vref may change from device to device, but it is 1.2 volts for the LM338 and the LM317 typical resistor value for R1 is 120 ohms best regards, Steve Thatcher -----Original Message----- Sent: Feb 22, 2005 7:32 AM To: Multiple recipients of list CHIPDIR-L <[email protected]> Cercuits using 3-terminal adjustable voltage regulators like the LM317 or LM338K 3-terminal adjustable regulators have a resistor from the Adjust pin to ground that one must set carefully to determine the output voltage of the regulator. There is also a fixed resistor that connects the Output pin of the regulator to the Adjust pin which appears to be a feedback path. What exactly is the formula for calculating the exact value for the feedback resistor if any? I read lots of stuff these days via speech synthesizer and this is the kind of information that typically gets put in to graphs or otherwise made difficult to read by putting it in to images rather than text. I can certainly understand why, but that is why I am asking here. Martin McCormick WB5AGZ Stillwater, OK OSU Information Technology Division Network Operations Group -- Author: Martin McCormick INET: [EMAIL PROTECTED] Fat City Hosting, San Diego, California -- http://www.fatcity.com --------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB CHIPDIR-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing). -- Author: Steve Thatcher INET: [EMAIL PROTECTED] Fat City Hosting, San Diego, California -- http://www.fatcity.com --------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB CHIPDIR-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).
