Specifications of modularEEG 

digital part:

isolated power supply:
•	input voltage: 7..12V dc, or 5V dc stabilized (from PC or mains adaptor)
•	isolated with DCDC-converter(TMA0505S):
Isolation voltage Input/Output 1'000 VDC
Isolation capacity Input/Output 60 pF typ.
Isolation resistance Input/Output >1'000 Mohm

isolated RS232 Data-lines (opto-isolated) 
•	2x 6N139 (RxD, TxD)
Viso > 2500 Vrms (Input-Output Momentary Withstand Voltage)
Resistance (Input-Output) Rio=10^12 ohm
Capacitance (Input-Output) Cio=0.6 pF

Microcontroller:
•	Atmel AVR AT90S4433 at 7.3728Mhz
with 6 channel (multiplexed) 10 bit resolution ADC, internal Sample and Hold Amplifier
  
analog part:

•	EEG-amplifier:
2differential mode (bipolar) channels
•	512uVp-p input range 
•	0.5uV resolution
•	lower –3dB corner frequency: 0.25Hz, 2nd order
•	upper –3dB corner frequency: 75Hz, 5-pole Butterworth
•	driven right leg circuit (DRL)
•	shield drivers for shielded electrodes
•	noise: about 1uVp-p over above specified bandwidth
•	common-mode rejection: typ. 115dB
•	Impedance, Differential 10^6 ohm || 1nF
•	Impedance, Common-Mode 10^10ohm || 60pF

misc.:

•	256Hz samplefrequency, (optional 200 Hz)
•	4 unused ADC-channels (input range +-2V)
•	4 TTL-inputs (for switches e.g. for marking events by the user)
•	4 LED-driver outputs (e.g. for light goggles)
•	1 PWM output 
•	hardware UART (RS232 transmission)
•	parameters are: 1 startbit, 8 data bits, 1 stopbit, no parity, 57600 baud)
•	on board calibration generator: 50uVpp 10Hz rectangle wave
•	easy in system programmable uC-EEPROM/Flashrom
•	uC-firmware written in AVR-GNU-C