LMN/NOPB Texas Instruments Audio Amplifiers 5-W AUDIO POWER AMP datasheet, inventory, & pricing. LMN Datasheet, LMN National Semiconductor 5-Watt Audio Amplifier Datasheet, buy LMN. The LM is a power audio amplifier for consumer applica- tion In order to hold system cost to a minimum gain is internally fixed at 34 dB A unique input stage.

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It’s worth mentioning that the above circuit can be simulated and will give the expected results, but you need to replace the upper NPN output transistor Q7 with a Darlington pair or you will not get symmetrical clipping.

The bypass cap C2 is optional as well, but if you don’t include it the power supply rejection is rather poor, so anything other than a battery supply may cause some hum.

Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet. The quiescent output voltage is set internally to be half the supply voltage, and by default the gain is 20 26dB.

The output is short-circuit proof with internal thermal limiting. If you want to know more, have a look at the datasheets. Of the three types, the LM is the more popular. There’s no doubt that a small amp with similar performance can be made using an opamp and a couple of transistors, but the total cost and component count will be a great deal higher than will be the case with one of these ICs.

Every so often, you’ll find a need for a low power amplifier. C5 is a supply bypass cap, and it should be as close to the supply pins as possible.

LM386, LM380 & LM384 Power Amplifiers

The circuit is shown for reference only, and is adapted from the datasheet but has been redrawn. The heatsink on the right can km384n fabricated from sheet copper, and I added two ‘spigots’ that can be inserted into the PCB to stabilise the heatsink against vibration.

See SNAA for circuit details. The load impedance needed is higher than any small speakers you can get, and you simply don’t build an amp using an LM if you need more than a few milliwatts. Uses range from signal tracers, workshop monitor amps to listen to distortion residuals for exampleor just a simple project for the fun of it.


Probably the most interesting thing to look at is the input stages. The minimum useful voltage is around 6V, and 12V is the maximum suggested for the LM For best thermal performance, the heatsink s should be soldered directly to the pins, and ideally will also have a good thermal bond with the top of the IC package.

The 8-pin version of the LM is capable of around 1W, but that’s under ideal conditions. The input capacitor is optional – you can connect the source or pot wiper directly to the input pin if you prefer. The supply voltage needs to be no more than 12V and the load impedance should not be less than 8 ohms. The negative input signal doesn’t get cut off as you might expect, because the emitter is still positive. None are anything special, and they are fairly low power the LM is only rated for mW into 8 ohms.

In order to hold system cost to a minimum, gain is internally fixed at 34 dB. The LM is similar, but uses 50k resistors at the inputs, and has two series resistors ohms and 1. Commercial use is prohibited without express written authorisation from Rod Elliott. The IC is useful for headphones, intercoms, portable radios etc.

Reproduction or re-publication by any means whatsoever, whether electronic, mechanical or electro-mechanical, is strictly prohibited under International Copyright laws. If these pins are linked by a 10uF capacitor, the gain is 46dB.

The LM is available in two packages – 8-pin and pin. The suggested heatsink designs are shown below. The datasheets don’t mention it, but there’s every chance that the ICs will oscillate if you fail to bypass the supply. LM or LM can use a supply voltage of 10V up to 22V or 26V respectively, but don’t even think about it if you don’t include heatsinks. Home – IC Supply – Link.


Feel free to include a nF multilayer ceramic bypass cap as close to the supply pins as possible it’s not shown in the above drawings.

LMN datasheet & applicatoin notes – Datasheet Archive

They can be run without a heatsink, but only for low power output, and care is lm384j to ensure the IC doesn’t overheat. However, the performance is such that I doubt it would meet the required standards for professional use, and I have never seen an LM used in pro gear.

These are certainly not hi-fi by any stretch of the imagination, but they are fine for a utility amplifier where a bit of distortion is unlikely to be a deal-breaker. That means that the maximum input voltage will be around mV RMS sinewave at the onset of clipping. The output automatically self-centers to one-half the supply voltage. Two are needed, one for each side of the IC.

LMN Datasheet(PDF) – TI store

The power supply can be anything you have handy, including a battery. The output automatically self-centers to one-half the. Quiescent Output Voltage is at One Half of the. It’s important to understand that the LM is not an opamp, and none of the traditional opamp circuits can be applied. While you may see it rated for up to 1W output, this is a little adventurous to put it mildly. It is possible to use a ground-plane on a PCB as a heatsink, but it’s not very effective and you need a lot of area to get what is still a sub-standard heatsink.

A unique input stage allows ground referenced input signals. The author Rod Elliott grants the reader the right to use this information for personal use only, and further allows that one 1 copy may be made for reference while ddatasheet the project.

It should be easy enough to fabricate a suitable heatsink if you have some sheet copper available.