Lm317 Application Notes Current Source

The ground of r2 can be returned near the ground of the load to provide remote sensing and improve load regulation.

Lm317 application notes current source.

Line regulation note 3 3 0 v vi vo 40 v 1 regline 0 02 0 07 v load regulation note 3. This optional capacitor improves ripple rejection. Operation of the lm317 down to 0v output requires the addition of a negative supply so that the adjustment terminal 20010204 figure 3. Similarly two current sources are available.

When the regulator input rises far enough c1a returns low q1 cuts off and capacitor charging ceases. Application information input output adjust lm317 2n2905 22 ω vi 5 kω 500 ω 120 ω 1n4002 see note a 10 µf see note b 10 µf 47 µf tip73 vo notes. 0 page 2 of 4. Application note 32 an32 5 an32f allowing q1 s gate trace b to rise.

The minimum load current is 30 ma. Current and 1 for resistor r1. 0 01 v line regulation 1 5 a output current adjustable output down to 1 25 v current limit constant with. One or both currents can be sent to the one output.

By sancho p updated december 02 2012. 0 1 load regulation typ. The load doesn t change the current from a constant current source in fact i could short out the output and maintain 120ma. Lm317 slvs044y september 1997 revised april 2020 lm317 3 terminal adjustable regulator 1 1 features 1 output voltage range adjustable from 1 25 v to 37 v output current greater than 1 5 a internal short circuit current limiting thermal overload protection output safe area compensation 2 applications atca solutions.

The lm317 serves a wide variety of applications including local on. High current adjustable regulator circuit. Ad7719 adc has a similar current source setup with the maximum current at 400 μa see figure 2. Lm317 used as current stabilizer in a test environment to find settings and limits.

The ic lm317 promises countless interesting and useful power enhancement circuits applicable in numerous fields where well dimensioned power supplies become crucially important. Adjustment and output the lm317 can be used as a precision current regulator. Lm117 lm317 n snvs774q may 2004 revised june 2020 lm117 lm317 n wide temperature three pin adjustable regulator 1 1 features 1 for a newer drop in alternative see the lm317 typ. Some assorted useful lm317 application circuits from national semiconductor pdf datasheet has been discretely explained in this chapter through the relevant circuit illustrations.

Applications figure 5 shows a 0v to 25v general purpose lab supply. Lm317 current source public. Note the lm317 will get hot and voltage not dropped by the load will be dropped by the pass transistor lm317 etc.