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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The interior design of an LM looks like this: Email required Address never made public. Can serve as positive, negative, shunt, pass, floating or switching regulator or as a temperature controller.

National Semiconductor

The collector voltage Vc driving the output does not need to be stabilized. From a power supply manufacturer I read some email correspondence with TI tech support where he also claimed more drift in recent parts. For getting an output voltage range from 2v to 7v you can use the circuit below, which is a Basic Voltage Regulator circuit using LM voltage regulator IC.

To use this IC for the different range of required output voltage, you can proceed with various circuits available in LM datasheet with having your needed output range. Darasheet also acts as a soft start feature. Naturally, it is frowned upon by a lot of designers that are just half as old. I added a reference study that compares voltage regulator noise. Support lm23 external pass transistorskeeping on-chip dissipation and therefore drift low.

This cancels the error amps base bias currents. Some extra bleeders are needed to make falling edge output regulations fast enough.


Although the LM can dissipate a few mW and deliver up to mA, better use an external pass transistor to do the hard work and keep the regulator chip cool. If you need to regulate lower voltages, the LM chip itself datawheet a separate power input at 10V minimum.

When you ask for the same basic parameters 40V, mA, … there is simply no better IC today. The datasheet is not very instructive on this, but the floating regulator variants will fail to regulate when the load resistance becomes to high. Which comparable ICs are so much better now? The LM is not discontinued at all, sold by TI in the millions, available from all electronic distributors and dirt cheap.

A lot of basic application circuits can be found in the LM datasheet. People used to 3-terminal regulators are in for a culture shock caused by the amount of design aspects to consider. 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 If you have a heavily overcompensated i.

Datasheef microscopic SMD cases available. Intolerant to missing or misdesigned compensation. First, ST went out of the LM business.

With less accurracy, you may go below that, but not by much. Minimum regulated output voltage is ca. The current limiting feature is implemented as a transistor that is turned on by the voltage drop on a current sensing resistor.

Notify me of new comments via email. We have only a factor of ca. It can able to provide a higher range of output voltage and current up to 10A by simply adding a dataasheet pass transistor with it, with having a wider range of operating temperature so the IC able to withstand for long.


Tempco is also very good, also l7m23 compared to newer chips. This terminal is directly supplied from the supply when not connected to series pass transistor. A schematic with all suggestions implemented can be seen at the bottom of this page. Compensation by the user.

Submitted by webmaster on 15 January Minimum Output for Floating Regulators. On a transistor level, you can see some design tricks by the legendary Bob Widlar: There is even an obsolete 80V version, the Datashedt. The LM values translate to about 0.

LM IC Pinout, Specifications, Equivalent & Datasheet

Especially when driving MOSFETs, you might need a bleeder resistor to make the falling edges fast enough for your needs. Its comparing apples and oranges. If we pragmatically summarize the pros and cons of this methusalem, we end up with something like this:. Try with different output voltages, load currents and input voltages. This is due to the 7. Click here for a larger resolution picture …. They dont make this part anymore.

If you want precision current control, dont try to do this with a pot sampling a fraction of voltage across a shunt measurement resistor.

They see this chip as an old-age part that has no merits today. If you use current limiting, protect the base of the limiting transistor by a 1K, e. Input voltage goes up tp 40V constant, with 50V pulses allowed.

Provide enough voltage headroom. Fill in your details below or click an icon to log in: