40V current source operates from -40 to +85°C

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The temperature coefficient of D1 offsets that of the LM317LZ, so a temperature range of -40 to +85°C will alter the current limit less than ±100 µA for the 5-mA limit shown. This works for currents from 2.5 to over 20 mA with no special heatsinking and accommodates VIN-VOUT of 40V dc. To use the current source/limit, place an LED, zener diode, switch, etc. in series with the circuit as shown. VIN minimum should be 3.5V plus the voltage drop of the series device.

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http://www.edn.com/archives/1995/062295/13di3.htm

This entry was posted on Saturday, November 3rd, 2007 at 11:29 pm and is filed under LM317, Power supply. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.