12 channel DC-coupled EEG amplifier

This is an open-source EEG amplifier project. It includes the schematic, the boardlayout and
the Gerber- and Excellonfiles.
No SMD/SMT components are used in this design. Licences used in this project is the Creative Commons Share Alike.

This amplifier has been designed to complete the ADC-box and it will fit in the same housing.

Properties

• channels: 12
• frequencyrange: DC - 1200 Hz
• gain: 20 x
• input lowpassfilter: 1th order, 1231 Hz
• RMS noise: less than 1 microVolt from 0.1 Hz to 70 Hz
• powersupply: +/- 1.5 Volt to +/- 18 Volt
• rail to rail output: yes

Downloads

• image of the schematic
• image of the boardlayout
• Eagle schematic and board files and the Gerber X, Excellon files
• partslist, including manufacturer codes and Farnell ordercodes
• drawing of the frontpanel in DXF format, can be edited with QCAD

• 12 channel ADC-board

Notes

Feedback

Report any errors, mistakes, omissions to teuniz@gmail.com

External links

Software used for this project

• Eagle CAD software used to edit the schematic and board
• Gerbv, a viewer used to review and check the Gerber X files
• QCAD, a multi-platform 2D CAD system used to design the front- and backpanel of the housing

Datasheets

• AD822
• enclosure/housing Hammond 1598H
• medical approved power adapter

Recommended reading

• Leakage Current Standards Simplified
• Converters Address Medical Equipment Compliance
• PDF version: Converters Address Medical Equipment Compliance (this PDF has the images/schematics)
• Designing Medical Electrical Equipment to Meet Safety Certification and Regulatory Requirements