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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Submitted by webmaster on 15 January Fill in your details below or click an icon to log in: Naturally, it is frowned upon by a lot of designers that ln723 just half as old. If you need to regulate lower voltages, the LM chip itself needs a separate power input at 10V minimum.

Try with different output voltages, load currents and input voltages. They see this chip as an old-age part that has no merits today.

Minimum dropout voltage is ca. Take all networks into account, and make sure that the reference divider and the output sampling network present the same impedance to the error amplifier inputs. Input voltage goes up tp 40V constant, with 50V pulses allowed. With less accurracy, you may go below that, but not by much.

Error amp bias current. After some ping-pong TI recommended the MIL-spec part and guaranteed that this would be free from drift. So, in case you have decided for an LM to make a good power supply, there are some rules of thumb that will make your life easier:. The current limiting feature is implemented as a transistor that is turned on by the voltage drop on a current sensing resistor. Click here for a larger resolution picture … A lot of basic application circuits can be found in the LM datasheet.


One of the best low noise regulators even today when hooked up properly. 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 Click here for a larger resolution picture …. I added a reference study that compares voltage regulator noise. Intolerant to missing or misdesigned compensation. Its comparing apples and oranges.

Gate parasitic suppression resistors of a few Ohms are also a good idea. There is even an obsolete 80V version, the LCB.

You can tailor the frequency response to your application but you also have to do that because there is no internal compensation. Notify me of dattasheet comments via email.

National Semiconductor – datasheet pdf

The superbeta bipolars in the error amp have a low, but nonzero bias current that can cause voltage shifts of a few millivolts across voltage divider or RC filter resistors. If you have a heavily overcompensated i. Also able to use as either linear or switching type regulator. 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.


A schematic with all suggestions implemented can be seen at the bottom of this page. Extended Temperature Range available.

You are commenting using your Facebook account. Yes, it will oscillate if you forget or undercompensate. They dont make this part anymore.

National Semiconductor

This wastes some power, but speed, noise and other performance criteria are a lot better with a few volts across the pass transistor. This also acts as a soft start feature. Silence or no reply. TL — Programmable Reference Voltage. From a power supply manufacturer I read some email correspondence with TI tech support where he also claimed more drift in recent parts.

For your bread-and-butter PSU, they are still fine and noise is quite low. Can serve as positive, negative, shunt, pass, floating or switching regulator or as a temperature controller. The curves of the limiting transistors Vbe voltages over temperature in the LM datasheet should make it absolutely clear that no precision can be expected here. A PNP pass transistor can further improve noise performance. 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.

Minimum regulated output voltage is ca. Current limiting sensitive to overload. Leave a Reply Cancel reply Enter your comment here