Programmable from 1µA to 10mA. □ ±3% initial accuracy. Description. The LM/LM/LM are 3-terminal adjustable current sources characterized by . LMM Texas Instruments Current & Power Monitors & Regulators NRND, alternate is LMM/NOPB datasheet, inventory, & pricing. LMM/NOPB Texas Instruments Current & Power Monitors & Regulators 3- TERM ADJ CURRENT SOURCE datasheet, inventory, & pricing.

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A couple of resistors and a comparator with built-in reference would lm3344m the job in a much simpler fashion. By clicking “Post Your Answer”, you acknowledge that you have read our updated terms of serviceprivacy policy and cookie policyand that your continued use of the website is subject to these policies.

LM from Texas Instruments

I don’t see a way in circuitlab datwsheet represent an actual LM, so the simulation likely won’t operate correctly. From there, it’s just a matter of tuning either the set resistor of the LM or the voltage threshold to trim to the setpoint.

This will vary over temperature and from unit to unit, that’s what they mean by ‘typical’. If the load impedance is high, then the current will be datashdet lower than the limit. The comparator could be something like half an LM The LM in this case does not have an infinite voltage with which to overcome the load impedance.

Datasheet «LM334»

So what you do is connect R2 directly between L and PE terminals. Any real current source will have a voltage limit beyond which it will not deliver a constant current. Remember that this circuit must act appropriately during faults – and then the LM is a short. The typical performance is shown in the datasheet in this graph:.


National Semiconductor

In the schematic, I1 represents the LM When the 1 mA of current is reached, it should begin to increase its resistance, thus increasing the voltage drop across it. It depends on GREATLY on how the LM is connected high side or low side, for example and how much your current is and how much error you can tolerate any monitor circuit will lower the output impedance.

The circuit in this case is a Ground Continuity Monitor. Othewise, the load is getting the maximum voltage that the source can provide, and is not running at full current.

Sign up or log in Sign up using Google. My goal is to make an alarm of sorts when that impedance datasyeet a threshold, and the way I want to do that is to detect when the is in current limiting mode. A small current from an AC supply is intentionally “leaked” to ground.

Post as a guest Name. Nope, it won’t work. You can increase the resistance of the divider if you can use a larger lm33m4 resistor R3 or a higher-gain transistor. Email Required, but never shown. If the voltage is more than 2. It’s not possible to give a good answer without much more information such as a complete schematic and accuracy requirements. It datasehet in the question. R2 completely determines the behavior of the system, when looked at from outside, and sets the leakage current.


I’d like to measure the voltage drop and light an LED really an optoisolator when it exceeds a threshold.

If it’s less than that it may or may not be working there is no minimum voltage below which is it is guaranteed to datassheet work. Sign up using Facebook.

So for low currents, it might be delivering more-or-less constant current at 0. If that current doesn’t flow, then that’s an error. The reference could be derived from a regulated supply voltage such as 5V with a voltage divider.

At 25C, the LM has a minimal drop-out voltage of about 0. Kuba Ober 1, 10 The current limiter is intended to limit the amount of ground leakage.

Usually when a current supplied less than the current required, there is a voltage drop. Note as well that the actual circuit ground is on the top side of R1 – Vout is the ground datashet for the purpose of this circuit. I need to use an opto between this circuit and the logic systems for safety. How to tell when an LM is limiting the current? R1 represents the ground impedance – the goal is to detect when it’s value exceeds 10k.