LM386

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The LM386N-1

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[edit]

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

The LM386 was invented by Ernie Leroy Long at Motorola in 1969. It was originally for part of a fuel injection system for a Ford Car.[citation needed]

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[edit]

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[edit]

  • 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.

Usage in amateur radio[edit]

The LM386 is very commonly used in the audio amplifier of low power QRP amateur radio rigs, like the Pixie.

See also[edit]

References[edit]

  1. ^ "Data Sheet (National Semiconductor)" (PDF). Texas Instruments. 2000. Retrieved 4 Nov 2013. 
  2. ^ "Data Sheet (Unisonic Technologies Co.)" (PDF). Unisonic Technologies Co. 2014. Retrieved 2 Sep 2015. 
  3. ^ "Data Sheet (New Japan Radio Co. Ltd.)" (PDF). New Japan Radio Co. Ltd. Retrieved 29 Aug 2015. 
  4. ^ "Data Sheet (New Japan Radio Co. Ltd.)" (PDF). New Japan Radio Co. Ltd. Retrieved 29 Aug 2015. 
  5. ^ "Data Sheet (New Japan Radio Co. Ltd.)" (PDF). New Japan Radio Co. Ltd. Retrieved 2 Sep 2015. 
  6. ^ "Single-in-line package outline drawing (New Japan Radio Co. Ltd.)" (PDF). New Japan Radio Co. Ltd. Retrieved 2 Sep 2015. 
  7. ^ "Texas Instruments completes acquisition of National Semiconductor". 
  8. ^ "LM386 audio amp Spice model?". 
  9. ^ "The EasyEDA Tesseract Guitar Practice Amp simulation files". 
  10. ^ "Tesseract Guitar Practice Amp". 
  11. ^ "Little Gem amps at runoffgroove". 
  12. ^ "Ruby amp at runoffgroove". 

External links[edit]

Historical Data Books