MEMS audio sensor omnidirectional digital microphone
Document overview
- Manufacturer or author: STMICROELECTRONICS
- PDF pages: 16
Technical content
Datasheet sections
- 1 Pin description
- 2 Acoustic and electrical specificati ons
- 2.1 Acoustic and electrical characte ristics
- 2.2 Timing characteristics
- 2.3 Frequency response
- 3 Sensing element
- 4 Absolute maximum ratings
- 5 Functionality
- 5.1 L/R channel selection
- 6 Application recommendations
- 7 Package mechanical data
- 8 Revision history
Features
■ Single supply voltage ■ Low power consumption ■ 120 dBSPL acoustic overload point ■ 62.6 dB signal-to-noise ratio ■ Omnidirectional sensitivity ■ –26 dBFS sensitivity ■ PDM single-bit output with option for stereo configuration ■ RHLGA package – Bottom-port design – SMD-compliant – EMI-shielded –E C O P A C K ®, RoHS and “Green” compliant
Applications
■ Mobile terminals ■ Laptop and notebook computers ■ Portable media players ■ VoIP ■ Speech recognition ■ A/V eLearning devices ■ Gaming and virtual reality input devices ■ Digital still and video cameras ■ Antitheft systems
Description
The MP34DB01 is an ultra-compact, low-power, omnidirectional, digital MEMS microphone built with a capacitive sensing element and an IC interface with stereo operation capability. The sensing element, capable of detecting acoustic waves, is manufactured using a specialized silicon micromachining process dedicated to produce audio sensors. The IC interface is manufactured using a CMOS process that allows designing a dedicated circuit able to provide a digital signal externally in PDM format. The MP34DB01 has an acoustic overload point of 120 dBSPL with a best on the market 62.6 dB signal-to-noise ratio and -26 dBFS sensitivity. The MP34DB01 is available in a bottom-port, SMD-compliant, EMI-shielded package and is guaranteed to operate over an extended temperature range from -40 °C to +85 °C. RHLGA 3x4x1 4LD Table 1. Device summary
1 Pin description
Figure 1. Pin connections Table 2. Pin description
1 CLK Synchronization input clock
2 LR Left/right channel selection
3 Vdd Power supply
4 DOUT Left/right PDM data output
2 Acoustic and electrical specifications
2.1 Acoustic and electrical characteristics
T = 25 °C, unless otherwise noted. Table 3. Acoustic and electrical characteristics
- Typical specificat ions are not guaranteed.
- Input clock in static mode.
- Time from the first cloc k edge to valid output data.
Table 4. Distortion specifications
2.2 Timing characteristics
Figure 2. Timing waveforms Table 5. Timing characteristics
2.3 Frequency response
Figure 3. Typical frequency response normalized at 1 kHz Table 6. Frequency response mask for digital microphones
- At T = 20 °C and acoustic stimulus = 1 Pa (94 dB SPL).
3 Sensing element
The sensing element shall mean the acoustic sensor consisting of a conductive movable plate and a fixed plate placed in a tiny silicon chip. This sensor transduces the sound pressure into the changes of coupled capacity between those two plates. Omron Corporation supplies this element for STMicroelectronics.
4 Absolute maximum ratings
Table 7. Absolute maximum ratings permanent damage to the part.
5 Functionality
5.1 L/R channel selection
L/R pin must be connected to Vdd or GND. Table 8. L/R channel selection
6 Application recommendations
Figure 4. MP34DB01 electrical connections Figure 5. MP34DB01 electrical connections for stereo configuration near as possible to pin 3 of the device (common design practice). The L/R pin must be connected to Vdd or GND (refer to Table 8).
5 Top view
7 Package mechanical data
specifications, grade definitions and product status are available at: www.st.com. and is qualified for soldering heat resistance according to JEDEC J-STD-020. Landing pattern and soldering recommendations are available at www.st.com. Figure 6. Recommended soldering profile limits Table 9. Recommended soldering profile limits
Figure 7. RHLGA 3 mm x 4 mm x 1 mm 4-lead package outline Table 10. RHLGA 3 mm x 4 mm x 1 mm 4-lead package dimensions
8 Revision history
Table 11. Document revision history
electrical characteristics
07-May-2012 7 Added V IOL, VIOH to Table 3: Acoustic and electrical characteristics 05-Jul-2012 8 Added Section 3: Sensing element Updated operating temperature range throughout datasheet