LT3080 LTSPICE Simulation error. (Dave PSU)

[xReM1x]

I set the current to 1.1A
as you can see, it set the current to 768mA.
I have no idea why is that.

[void_error]

Why is R1 shorted?

[xReM1x]

Why is R1 shorted?

shorted?

still the same thing, it does limit the current, its just not accurate at all.

[void_error]

Try using a LTC6101 for current sensing.

[xReM1x]

Try using a LTC6101 for current sensing.

nothing.

[void_error]

You're using it wrong. Check the datasheet first. Your current sense circuit using the LTC6101 should look like this (without the LTC2433):


You need R_IN and R_OUT for it to work.

[xReM1x]

You're using it wrong. Check the datasheet first. Your current sense circuit using the LTC6101 should look like this (without the LTC2433):


You need R_IN and R_OUT for it to work.

[indole]

Have a look at the current limit input-to-output differential graph on the datasheet.  I have a feeling that dropping 14V is what's causing it to limit it's output current to 800mA.

[void_error]

There's that and there's also the fact that the LT1013 doesn't swing close enough to ground (from the datasheet it can only go down to V- +1V) so the transistor doesn't switch off. You might want to use the LT1368 instead.

[indole]

Unless I'm mistaken in reading the LT1013 datasheet, in single supply operation it can swing within a couple mV of ground.

The LT1013/LT1014 are fully specified for single supply
operation, i.e., when the negative supply is 0V. Input
common mode range includes ground; the output swings
within a few millivolts of ground.

[void_error]

Unless I'm mistaken in reading the LT1013 datasheet, in single supply operation it can swing within a couple mV of ground.

The LT1013/LT1014 are fully specified for single supply
operation, i.e., when the negative supply is 0V. Input
common mode range includes ground; the output swings
within a few millivolts of ground.

I was looking at the output voltage swing specified for R_L=2k and +/-15V supply which is not the case here, oops...

Anyway, xReM1x, here's a version that will work. You had R1 set too low, giving you 0.1V/1A at the output. You could go with an op amp for current sensing but your accuracy will depend on the op amp's input offset voltage and the matching of the four resistors of the difference amplifier. LTC6101 is the easy way here and it will work.


EDIT: V3 should be 0.5V not 5V.