{"product_id":"adafruit-stereo-3-7w-class-d-audio-amplifier","title":"Adafruit Stereo 3.7W Class D Audio Amplifier","description":"\u003cp\u003eThis incredibly small stereo amplifier is surprisingly powerful - able to deliver 2 x 3.7W channels into 3 ohm impedance speakers. Inside the miniature chip is a class D controller, able to run from 2.7V-5.5VDC.\u003c\/p\u003e\n\u003cp\u003eSince the amp is a class D, its incredibly efficient (over 90% efficient when driving an 8Ω speaker at over a Watt) - making it perfect for portable and battery-powered projects. It has built in thermal and over-current protection but we could barely tell it got hot. This board is a welcome upgrade to basic \"LM386\" amps!\u003c\/p\u003e\n\u003cp\u003eThe inputs of the amplifier go through 1.0uF capacitors, so they are fully 'differential' - if you don't have differential outputs, simply tie the R- and L- to ground. The outputs are \"Bridge Tied\" - that means they connect directly to the outputs, no connection to ground. The output is a 360KHz square wave PWM that is then 'averaged out' by the speaker coil - the high frequencies are not heard. All the above means that you can't connect the output into another amplifier, it should drive the speakers directly.\u003c\/p\u003e\n\u003cp\u003eComes with a fully assembled and tested breakout board with 1.0uF input capacitors. Adafruit also include header to plug it into a breadboard, 3.5mm screw-terminal blocks so you can easily attach\/detach your speakers, and a 2x4 header + jumper to change the amplifier gain on the fly. You will be ready to rock in 15 minutes! \u003cstrong\u003eSpeakers are not included, use any 3ohm or greater impedance speakers.\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eOutput Power: 3.7W at 3Ω, 10% THD, 1.7W at 8Ω, 10% THD, with 5V Supply\u003c\/li\u003e\n\u003cli\u003ePasses EMI limit unfiltered with up to 12 inches (30 cm) of speaker cable\u003c\/li\u003e\n\u003cli\u003eHigh 83dB PSRR at 217Hz\u003c\/li\u003e\n\u003cli\u003eSpread-Spectrum Modulation and Active Emissions Limiting\u003c\/li\u003e\n\u003cli\u003eFive pin-selectable gains: 6dB, 9dB, 12dB, 15dB and 18dB. Select with a jumper or by setting the G and G' breakout pins (see \u003ca href=\"http:\/\/www.adafruit.com\/datasheets\/MAX98306schem.png\" target=\"_blank\"\u003eschematic for breakout board showing gain pin settings\u003c\/a\u003e for details)\u003c\/li\u003e\n\u003cli\u003eExcellent click-and-pop suppression\u003c\/li\u003e\n\u003cli\u003eThermal and short-circuit\/over-current protection\u003c\/li\u003e\n\u003cli\u003eLow current draw: 2mA quiescent and 10uA in shutdown mode\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003eTECHNICAL DETAILS\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e\u003ca href=\"https:\/\/learn.adafruit.com\/stereo-3-7w-class-d-audio-amplifier\/downloads\" target=\"_blank\"\u003eDatasheet, schematic, and Fritzing library available in the product tutorial\u003c\/a\u003e\u003c\/p\u003e\n\u003cp\u003eDimensions (without 0.1\" header):\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eLength:28.25mm\/1.11in\u003c\/li\u003e\n\u003cli\u003eWidth:24.15mm\/0.95in\u003c\/li\u003e\n\u003cli\u003eHeight:3.03mm\/0.12in\u003c\/li\u003e\n\u003cli\u003eWeight:2.33g\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Adafruit","offers":[{"title":"Default Title","offer_id":315959611,"sku":"ADA987","price":15.0,"currency_code":"AUD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0174\/1800\/products\/987.jpg?v=1539264774","url":"https:\/\/shop.pimoroni.com\/en-au\/products\/adafruit-stereo-3-7w-class-d-audio-amplifier","provider":"Pimoroni Ltd","version":"1.0","type":"link"}