{"product_id":"adafruit-stemma-piezo-driver-amp-pam8904","title":"Adafruit STEMMA Piezo Driver Amp - PAM8904","description":"\u003cp\u003ePiezos make noise when you put an AC voltage across them: and the bigger the Vpp the louder they are.\u003c\/p\u003e\n\u003cp\u003eWith your standard 3V logic microcontroller you can make 3Vpp with a PWM out, or 6Vpp differential with two complimentary outputs. But what if you want even louder? Or if you're using a piezo to sense distance using ultrasonic bounces?\u003c\/p\u003e\n\u003cp\u003eThe nifty \u003ca href=\"https:\/\/www.digikey.com\/short\/p9bwzp2t\"\u003ePAM8904\u003c\/a\u003e is an amplifier specifically designed for driving piezo elements - and unlike audio amplifiers it's good for up to 300 KHz! It's a switched-cap piezo driver that has bridge-tied load (BTL) output and up to 3x voltage multiplication thanks to a built in boosting circuit for up to ~13Vpp.\u003c\/p\u003e\n\u003cp\u003eAdafruit whipped up a quick breakout in our 2mm JST-PH STEMMA form-factor to make it easy for anyone who wants to beep their boops very loudly. \u003c\/p\u003e\n\u003cp\u003eUsage is easy: power with 3 to 5VDC on the Vin and GND pins. Then provide a square wave on the signal pin, from 20Hz to 300KHz - any duty cycle is ok but 50% will probably work best. There's a dual DIP switch to set the gain: you can set it to off (zero gain), x1 gain, x2 gain and x3 gain. The output is differential so 2x gain will give you 4xVin peak-to-peak across the piezo lines. Connect your piezo to the terminal block and you're ready to rock. \u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003ePlease note: If you are powering the driver from 5VDC, don't set the gain to x3 because the 15V output is higher than the driver is specified for.\u003c\/strong\u003e (Yeah we also sorta wondered why the chip manufacturer allows it). So if you are using \u003cstrong\u003e3.3V power, x3 gain is OK\u003c\/strong\u003e and will give you about 10V out but if you're powering with \u003cstrong\u003e5V use 2x gain\u003c\/strong\u003e max to keep the max voltage at 10V.\u003c\/p\u003e\n\u003cp\u003e\u003ca href=\"https:\/\/www.adafruit.com\/product\/1739\"\u003ePiezo element\u003c\/a\u003e and \u003ca href=\"https:\/\/www.adafruit.com\/product\/3893\"\u003e3-pin JST PH cable\u003c\/a\u003e not included!\u003c\/p\u003e\n\u003ch2\u003eLearn\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003ca href=\"https:\/\/learn.adafruit.com\/adafruit-stemma-piezo-driver-amp\"\u003ePrimary Guide: Adafruit STEMMA Piezo Driver Amp\u003c\/a\u003e\u003cbr\u003eAmp up your piezo\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"https:\/\/learn.adafruit.com\/products\/5791\/guides\" target=\"_blank\" rel=\"noopener\"\u003eSee All Guides\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Adafruit","offers":[{"title":"Default Title","offer_id":41128287109203,"sku":"ADA5791","price":4.95,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0174\/1800\/files\/5791-00.jpg?v=1698908870","url":"https:\/\/shop.pimoroni.com\/en-eu\/products\/adafruit-stemma-piezo-driver-amp-pam8904","provider":"Pimoroni Ltd","version":"1.0","type":"link"}