# Adafruit STEMMA Piezo Driver Amp
## Overview
Piezos make noise when you put an AC voltage across them - and the bigger the voltage, the louder they are. With your standard 3V logic microcontroller you can make 3 volts peak to peak (Vpp) with a PWM out, or 6Vpp differential with two complementary outputs. But what if you want even louder? Or if you're using a piezo to sense distance using ultrasonic bounces?
We found the nifty [PAM8904](https://www.digikey.com/short/p9bwzp2t), which 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.
We 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.
Usage 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.
**Please 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.** (Yeah we also sorta wondered why the chip manufacturer allows it). So if you are using **3.3V power, x3 gain is OK** and will give you about 10V out but if you're powering with **5V use 2x gain** max to keep the max voltage at 10V.
[Piezo element](https://www.adafruit.com/product/1739) and [3-pin JST PH cable](https://www.adafruit.com/product/3893) not included! But we stock 'em in the shop if you want to pick up separately.
- [Next Page](https://learn.adafruit.com/adafruit-stemma-piezo-driver-amp/pinouts.md)
## Primary Products
### Adafruit STEMMA Piezo Driver Amp - PAM8904
[Adafruit STEMMA Piezo Driver Amp - PAM8904](https://www.adafruit.com/product/5791)
Piezos make noise when you put an AC voltage across them: and the bigger the Vpp the louder they are. With 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...
In Stock
[Buy Now](https://www.adafruit.com/product/5791)
[Related Guides to the Product](https://learn.adafruit.com/products/5791/guides)
## Featured Products
### Large Enclosed Piezo Element w/Wires
[Large Enclosed Piezo Element w/Wires](https://www.adafruit.com/product/1739)
This large (30mm diameter) piezo element is nicely enclosed with mounting holes so you can attach easily. Piezo elements convert vibration to voltage or voltage to vibration. That means you can use this as a buzzer for making beeps, tones and alerts AND you can use it as a sensor, to detect...
In Stock
[Buy Now](https://www.adafruit.com/product/1739)
[Related Guides to the Product](https://learn.adafruit.com/products/1739/guides)
### STEMMA JST PH 2mm 3-Pin to Male Header Cable - 200mm
[STEMMA JST PH 2mm 3-Pin to Male Header Cable - 200mm](https://www.adafruit.com/product/3893)
This cable will let you turn a JST PH 3-pin cable port into 3 individual wires with high-quality 0.1" male header plugs on the end. We're carrying these to match up with our Hallowing, for extending and connecting sensors or LEDs - and the wires are even color coded!
In Stock
[Buy Now](https://www.adafruit.com/product/3893)
[Related Guides to the Product](https://learn.adafruit.com/products/3893/guides)
### STEMMA JST PH 2mm 3-Pin to Female Socket Cable - 200mm
[STEMMA JST PH 2mm 3-Pin to Female Socket Cable - 200mm](https://www.adafruit.com/product/3894)
This cable will let you turn a JST PH 3-pin cable port into 3 individual wires with high-quality 0.1" female header sockets on the end. We're carrying these to match up with our Hallowing, for extending and connecting sensors or LEDs - and the wires are even color coded!
In Stock
[Buy Now](https://www.adafruit.com/product/3894)
[Related Guides to the Product](https://learn.adafruit.com/products/3894/guides)
### JST PH 2mm 3-pin Plug-Plug Cable - 100mm long
[JST PH 2mm 3-pin Plug-Plug Cable - 100mm long](https://www.adafruit.com/product/4336)
This cable is a little over 100mm / 4" long and fitted with JST-PH 3-pin connectors on either end.
We dig the solid and compact nature of these connectors and the latch that keeps the cable from coming apart easily. We're carrying these to
In Stock
[Buy Now](https://www.adafruit.com/product/4336)
[Related Guides to the Product](https://learn.adafruit.com/products/4336/guides)
### JST PH 2mm 3-pin Plug to Color Coded Alligator Clips Cable
[JST PH 2mm 3-pin Plug to Color Coded Alligator Clips Cable](https://www.adafruit.com/product/4030)
This cable will let you turn a JST PH 3-pin cable port into 3 individual wires with grippy mini alligator clips. We're carrying these to match up with any of our boards or breakouts with 3-pin 'STEMMA' connectors on them such as the
In Stock
[Buy Now](https://www.adafruit.com/product/4030)
[Related Guides to the Product](https://learn.adafruit.com/products/4030/guides)
## Related Guides
- [PowerWash Simulator Nozzle Controller](https://learn.adafruit.com/powerwash-simulator-nozzle-controller.md)
- [Adafruit IoT Button with NeoPixel BFF](https://learn.adafruit.com/adafruit-iot-button-with-neopixel-bff.md)
- [Adafruit Audio BFF](https://learn.adafruit.com/adafruit-audio-bff.md)
- [Adafruit LTC4316 I2C Address Translator](https://learn.adafruit.com/adafruit-ltc4316-i2c-address-translator.md)
- [Naughty or Nice Machine](https://learn.adafruit.com/naughty-or-nice-machine.md)
- [Adafruit STEMMA Soil Sensor - I2C Capacitive Moisture Sensor](https://learn.adafruit.com/adafruit-stemma-soil-sensor-i2c-capacitive-moisture-sensor.md)
- [Circuit Playground Express Automatic Sunglasses](https://learn.adafruit.com/circuit-playground-express-auto-sunglasses.md)
- [Google Graveyard with Adafruit MagTag](https://learn.adafruit.com/google-graveyard-with-adafruit-magtag.md)
- [Adafruit AM2320 Sensor](https://learn.adafruit.com/adafruit-am2320-temperature-humidity-i2c-sensor.md)
- [Adafruit Feather RP2350 with HSTX](https://learn.adafruit.com/adafruit-feather-rp2350.md)
- [Adafruit Audio FX Sound Board](https://learn.adafruit.com/adafruit-audio-fx-sound-board.md)
- [Analog Devices ADXL343 Breakout Learning Guide](https://learn.adafruit.com/adxl343-breakout-learning-guide.md)
- [Create a Memory Game on Fruit Jam Metro RP2350](https://learn.adafruit.com/create-a-memory-game-on-metro-rp2350.md)
- [CircuitPython Libraries on MicroPython using the Raspberry Pi Pico](https://learn.adafruit.com/circuitpython-libraries-on-micropython-using-the-raspberry-pi-pico.md)
- [Adafruit NeoKey 1x4 QT I2C Breakout](https://learn.adafruit.com/neokey-1x4-qt-i2c.md)