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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LM is an adjustable voltage regulator IC used for shunt regulator, current regulator, and temperature controller. 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.
Especially when driving MOSFETs, you might need a bleeder resistor to make the falling edges fast enough for your needs. Tempco is also very good, also when compared to newer chips. Provide enough voltage headroom. A lot of basic application circuits can be found in the LM datasheet.
With less accurracy, you may go below that, but not by much.
National Semiconductor – datasheet pdf
The current limiting feature is implemented as a transistor that is turned on by the voltage drop on a current sensing resistor. After some ping-pong TI recommended the MIL-spec part and guaranteed that dahasheet would be free from drift.
Naturally, it is frowned upon by a lot of designers that are just half as old. On a transistor level, you can see some design tricks by the legendary Bob Widlar: Which comparable ICs are so much better now? Error amp bias current. Intolerant to missing or misdesigned compensation. There are only better ones with low voltage 10V and lessand they cost a lot more than a LM Leave a Reply Cancel reply Enter your comment here Also able to use as either linear or switching type regulator.
A Collection of Proper Design Practices using the LM IC Regulator – Electronic Projects for Fun
They see this chip as an old-age part that has no merits today. Pin configuration Pin No. The LM values translate to about 0. Submitted by webmaster on 15 January The curves of the limiting transistors Vbe voltages over temperature in the LM datasheet dqtasheet make it absolutely clear that no precision can be expected here. Minimum regulated output voltage is ca. This also acts as a soft start feature.
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 This terminal is directly datashee from the supply when not connected to series pass transistor. Gate parasitic suppression resistors of a few Ohms are also a good idea. Yes, it will oscillate if you forget or undercompensate. You can tailor the frequency response to your application but you also have to do that because there is no internal compensation.
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. When you ask for the same basic parameters 40V, mA, … there is simply no better IC today.
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. People used to 3-terminal regulators are in for a culture shock caused by the amount of design aspects to consider.
If we pragmatically summarize the pros and cons of this methusalem, we end up with something like this: It can be found here. The datasheet is not very instructive on this, but the floating regulator variants will fail lm72 regulate when the load resistance becomes to high. 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.
If you use current limiting, protect the base of the limiting transistor by a 1K, e. If you need to regulate lower voltages, the LM chip itself needs a separate power input at 10V minimum. Datashert on a buried Zener low noise reference, it datazheet 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.
Its comparing apples and oranges. If you want precision current daasheet, dont try to do this with a pot sampling a fraction of voltage across a shunt measurement resistor. Moderate error amplifer gain. Try with different output voltages, load currents and input voltages.
Extended Temperature Range available.
Click here for a larger resolution picture … A lot of basic datsheet circuits can be found in the LM datasheet. No wonder after 50 years, it is known what you may expect and what not. From a power supply manufacturer I read some email correspondence with TI tech support where he also claimed more drift in recent parts. Fill in your details datsheet or click an icon to log in: Compensation by the user.
For your bread-and-butter PSU, they are still fine and noise is quite low. This is due to the 7. Silence or no reply.
We have only a factor of ca. No microscopic SMD cases available. I added a reference study that compares voltage regulator noise. First, ST went out of the LM business.