# Adafruit STEMMA Piezo Driver Amp - PAM8904

**Type:** Product page · **SKU:** ADA5791 · **Brand:** [Adafruit](https://core-electronics.com.au/brands/adafruit-australia)
**Page:** https://core-electronics.com.au/adafruit-stemma-piezo-driver-amp-pam8904.html ([markdown](https://core-electronics.com.au/adafruit-stemma-piezo-driver-amp-pam8904.html.md))

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...

## Pricing

- **Price:** $9.95 (inc GST) — $9.05 AUD, exc GST
- **Quantity discounts:** 10+ $8.77 (exc GST) · 50+ $8.59 (exc GST)

## Availability & dispatch

- Available with a lead time — expect dispatch between Aug 31 and Sep 02.

## Description

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 a piezo to sense distance using ultrasonic bounces?

Adafruit found the nifty [PAM8904](https://core-electronics.com.au/attachments/uploads/PAM8904E.pdf), 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.

Adafruit whipped up a quick breakout in Adafruit's 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. Theres 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 They 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://core-electronics.com.au/large-enclosed-piezo-element-w-wires.html) and [3-pin JST PH cable](https://core-electronics.com.au/jst-ph-3-pin-to-male-header-cable-200mm.html) not included!

## Technical Details

Product Dimensions: 22.5mm x 17.7mm x 10.2mm / 0.9" x 0.7" x 0.4"

Product Weight: 2.8g / 0.1oz

![RoHS 2 2011 65 EU Compliant](https://core-electronics.com.au/attachments/localcontent/RoHS2_2011_65_EU_7356c5574c.svg)![RoHS 2 2015 863 EU Compliant](https://core-electronics.com.au/attachments/localcontent/RoHS2_2015_863_EU_86773f57f9.svg)

## Images

- [Product image 1](https://core-electronics.com.au/media/catalog/product/A/D/ADA5791-1.jpg)