LM is an adjustable voltage regulator IC used for shunt regulator, current regulator, and temperature controller. The LM LMC is a voltage regulator designed primar- ily for series regulator applications By itself it will supply output currents up to mA but external. Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet. 2All trademarks are the property of their respective.

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Relying on a buried Zener low noise reference, it can compete with a lot of newer chips when it comes to stability it does have a long term stability rating in the datasheet, few new chips have that.

A lot of basic application circuits can be found in the LM datasheet. You are commenting using your Facebook account.

If you want precision current control, dont try to do this with a pot sampling a fraction of voltage across a shunt measurement resistor. This cancels om723 error amps base bias currents. The performance of an LM is not bad at all, especially for noise and long term stability. The LM values translate to about 0. Before you specify a compensation cap, run a few tests using SPICE to see if gain and phase margins are in order.

L7m23 or no reply.

National Semiconductor – datasheet pdf

They dont make this part anymore. With less accurracy, datahseet may go below that, but not by much. Error amp bias current. Its a self-heated reference. Both have been making s for decades, and after the sale TI took over the National Semiconductor designation of LM and used their own of uA The curves of the limiting transistors Dayasheet voltages over temperature in the LM datasheet should make it absolutely clear that no precision can be expected here.


Email required Address never made public. The LM is a classic, now available for 50 continuous years and still going strong. For your bread-and-butter PSU, they are still datwsheet and noise is quite low. People used to 3-terminal regulators are in for a culture shock caused by the amount of design aspects to consider.

LM Datasheet(PDF) – National Semiconductor (TI)

On a transistor level, you can see some design tricks datashewt the legendary Bob Widlar: It can able to provide a higher range of output voltage and current up to 10A by simply adding ddatasheet series pass transistor with it, with having a wider range of operating temperature so the IC able to withstand for long.

The load must be able to drain at least the supply current of the circuit without exhibiting a voltage higher than the desired output voltage. For finding the value of output voltage for this circuit you can use the formula below:. I added a reference study that compares voltage regulator noise.

First, ST went out of the LM business. No wonder after 50 years, it is known what you may expect and what not.


But this IC is specially designed for series regulator application. This also acts as a soft start feature. Yes, it will oscillate if you forget or undercompensate.

National Semiconductor

This is due to the 7. The way to go is either high side sensing with an op amp that can do that, or a floating design like the famous Elektor one from 1 x LM, 2 x LM Not a very high PSRR. If you have a heavily overcompensated i. One of the best low noise regulators even today when hooked up properly. The current limiting feature is implemented as a transistor that is turned on by the voltage drop on a current sensing resistor. Pin configuration Pin No. Which comparable ICs are so much better now?

From a power supply manufacturer I read some email correspondence with TI tech support where he also claimed more drift in recent parts. As I found out and others did as well their consumer parts where a bit drifty within spec limitsprobably by a conversion to a new manufacturing process with not just improvements as a consequence.

Try with different output voltages, load currents and input voltages. If we pragmatically summarize the pros and cons of this methusalem, we end up with something like this:. We have only a factor of ca.