SparkFun Launches Compact Breakout Board for the Knowles SPH8878LR5H-1 Analog MEMS Microphone
On-board op-amp introduces a bias and boosts the signal ready for direct connection to your microcontroller's ADC pin.
SparkFun has launched a compact breakout board designed to make it easier to get audio into your projects, combining a MEMS microphone and an op-amp for direct connection to a microcontroller.
"The SparkFun Analog MEMS Microphone Breakout makes it easy to work with the SPH8878LR5H-1 analog microphone from Knowles," the company explains of its latest creation. "This board features an op-amp to bring the output of the microphone to a usable level, allowing you to plug directly into an ADC [Analog to Digital Converter] on a microcontroller or something like the SparkFun Spectrum Shield."
The op-amp isn't just there to amplify the signal from the microphone, though: It also adds a bias voltage equal to half VCC. "With sound sources such as a normal speaking voice a few feet away from the microphone," the company notes, "the AUD output signal will be at about 200mV peak-to-peak."
The board is designed to operate at voltages of 2.3-3.6V, and with an average current consumption claimed at 265µA. The microphone offers a frequency range of 7Hz to 36kHz, a 66dBV/Pa signal-to-noise ratio, and a 44dBV/Pa sensitivity.
It's not SparkFun's first MEMS microphone breakout, though: The company had launched two other variants in the past, one based on the Analog ADMP401 and the other on the InvenSense ICS-40180. The new model, the company promises, should be a pin-compatible drop-in replacement.
More details are available in the hookup guide, along with sample code; the breakout board itself can now be ordered from the SparkFun store at $6.95 before volume discounts.