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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You can tailor the frequency response to your application but you also have to do that because there is no internal compensation. This is due to the 7. It can able to provide a higher range of output voltage and current up to 10A by simply adding a series pass transistor with it, with having a wider range of operating datawheet so the IC able to withstand for long. Submitted by webmaster on 15 January Not a very high PSRR.
This cancels the error amps base bias currents. We have only a factor of ca.
The collector voltage Vc driving the output does not dataeheet to be stabilized. If you need to regulate lower voltages, the LM chip itself needs a separate power input at 10V minimum. If we pragmatically summarize the pros and cons of this methusalem, we end up with something like this: You are commenting using your Twitter account.
Error amp bias current. Dataaheet — Programmable Reference Voltage. There are only better ones with low voltage 10V and lessand they cost a lot more than a LM Intolerant to missing or misdesigned compensation.
Naturally, it is frowned upon by a lot of designers that are just half as old. The net and some manufacturers application notes are datawheet a good source of information. Fill in your details below or click an icon to log in: Both have been making s for decades, and after the sale TI took over the National Datashest designation of LM and used their own of uA From a power supply manufacturer I read some email correspondence with TI tech support where he also claimed more drift in recent parts.
For finding the value of output voltage for this circuit you can use the formula below:.
Tempco is also very good, also when compared to newer chips. The LM is not discontinued at all, sold by TI in the millions, available from all electronic distributors and dirt cheap. 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.
When you ask for the same basic parameters 40V, mA, … there is simply no better IC today. They see this chip as an old-age part that has no merits today.
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. 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 l723.
Before you datasheef a compensation cap, run a few tests using SPICE to see if gain and phase margins are in order.
If you have a heavily overcompensated i. The datasheet is not very instructive on this, but the floating regulator variants will fail to regulate when the load resistance becomes to high. A lot of basic application circuits can be found in the LM datasheet.
LM Datasheet(PDF) – National Semiconductor (TI)
So, in case you have decided for an LM to make a datashret power supply, there are some rules of thumb that will make your life easier:.
Dataeheet of the best low noise regulators even today when hooked up properly. Click here for a larger resolution picture … A lot of basic application circuits can be found in the LM datasheet. Support for external pass transistorskeeping on-chip dissipation and therefore drift low. Minimum dropout voltage is ca. Extended Temperature Range available.
Compensation by the user. A schematic where all this has been implemented can be see below: 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 No microscopic SMD cases available. 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. Leave a Reply Cancel reply Enter your comment here Reason one is the low noise buried Zener reference, reason two is the fact that the reference voltage can be noise filtered before going into the error amp.