LM386
The LM386 is an integrated circuit containing a low voltage audio power amplifier.[1] It is suitable for battery-powered devices such as radios, guitar amplifiers, and hobby electronics projects. The IC consists of an 8 pin dual in-line package (DIP-8) and can output 0.25 to 1 watts of power depending on the model using a 9-volt power supply.
Models
There are three different models of the LM386 that have slightly different specifications, outlined below.
| Chip Name | Min Voltage | Max Voltage | Minimum Output Power | Typical Output Power | Load Impedance |
| LM386N-1 | 4 volts | 12 volts | 250 mW | 325 mW | 8 ohms |
| LM386N-3 | 4 volts | 12 volts | 500 mW | 700 mW | 8 ohms |
| LM386N-4 | 5 volts | 18 volts | 700 mW | 1000 mW | 32 ohms |
Almost identical versions of the device are available from Unisonic (Unisonic Technologies Co. or UTC) as the LM386 [2] and the New Japan Radio Co. Ltd. (JRC) [3] as the NJM386 [4] and NJM386B.[5]
The JRC devices are also available in a single-in-line package.[6]
JRC devices, marked as 386 JRC, are sometimes misleadingly referred to as the JRC386.
SPICE simulation models
Although National Semiconductor and Texas Instruments (who bought Nat Semi in 2011[7]) do not provide an official SPICE model for the LM386, there are two independently developed models freely available:
- The original "No-Frills LM386 Model" by Dave Dilatush.[8]
- An improved model, "The EasyEDA LM386EE spice model" developed for the simulations of the "Tesseract Guitar Practice Amplifier" project.[9]
Usage in guitar amplifiers
- The LM386 is one of the most common amps used in DIY guitar preamplifiers and sustainers due to its ability to run on a single 9V battery.
- The EasyEDA "Tesseract" Guitar Practice Amplifier is a versatile design based on the LM386 and features distortion and full-wave rectification effects.[10]
- The well-known "Smokey Amp" created by Bruce Zinky uses an LM386 and is notable for being able to fit in a cigarette package.
- The "Little Gem" and "Little Gem MkII" are modified/cloned versions of the "Smokey Amp".[11]
- The "Ruby" amp[12] is a modified version of a Little Gem amplifier.
- The Marshall MS-2 and MS-4 miniature practice amplifiers use a single-in-line packaged NJM386 manufactured by JRC.
See also
References
- ↑ "Data Sheet (National Semiconductor)" (PDF). Texas Instruments. 2000. Retrieved 4 Nov 2013.
- ↑ "Data Sheet (Unisonic Technologies Co.)" (PDF). Unisonic Technologies Co. 2014. Retrieved 2 Sep 2015.
- ↑ "Data Sheet (New Japan Radio Co. Ltd.)" (PDF). New Japan Radio Co. Ltd. Retrieved 29 Aug 2015.
- ↑ "Data Sheet (New Japan Radio Co. Ltd.)" (PDF). New Japan Radio Co. Ltd. Retrieved 29 Aug 2015.
- ↑ "Data Sheet (New Japan Radio Co. Ltd.)" (PDF). New Japan Radio Co. Ltd. Retrieved 2 Sep 2015.
- ↑ "Single-in-line package outline drawing (New Japan Radio Co. Ltd.)" (PDF). New Japan Radio Co. Ltd. Retrieved 2 Sep 2015.
- ↑ "Texas Instruments completes acquisition of National Semiconductor".
- ↑ "LM386 audio amp Spice model?".
- ↑ "The EasyEDA Tesseract Guitar Practice Amp simulation files".
- ↑ "Tesseract Guitar Practice Amp".
- ↑ "Little Gem amps at runoffgroove".
- ↑ "Ruby amp at runoffgroove".