Lm317 Application Notes Current Source

Some assorted useful lm317 application circuits from national semiconductor pdf datasheet has been discretely explained in this chapter through the relevant circuit illustrations.

Lm317 application notes current source.

The minimum load current is 30 ma. 0 01 v line regulation 1 5 a output current adjustable output down to 1 25 v current limit constant with. Applications figure 5 shows a 0v to 25v general purpose lab supply. This optional capacitor improves ripple rejection.

One or both currents can be sent to the one output. Lm317 current source public. Ad7719 adc has a similar current source setup with the maximum current at 400 μa see figure 2. Note the lm317 will get hot and voltage not dropped by the load will be dropped by the pass transistor lm317 etc.

High current adjustable regulator circuit. Current and 1 for resistor r1. By sancho p updated december 02 2012. Operation of the lm317 down to 0v output requires the addition of a negative supply so that the adjustment terminal 20010204 figure 3.

0 1 load regulation typ. The ground of r2 can be returned near the ground of the load to provide remote sensing and improve load regulation. 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. This turns on q1 and its source trace c drives current trace d into l2 and the 1000μf capacitor raising regulator input voltage.

Lm317 used as current stabilizer in a test environment to find settings and limits. 0 page 2 of 4. Behavioral source constant current source lm317 newbie test cb current source public. Adjustment and output the lm317 can be used as a precision current regulator.

Line regulation note 3 3 0 v vi vo 40 v 1 regline 0 02 0 07 v load regulation note 3. 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 ic lm317 promises countless interesting and useful power enhancement circuits applicable in numerous fields where well dimensioned power supplies become crucially important. Both current sources are 200 μa and can be controlled in a similar manner to the ad7794 adc.

When the regulator input rises far enough c1a returns low q1 cuts off and capacitor charging ceases. Similarly two current sources are available. 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.