Digital Stimulus Isolation

Microelectrode Amplifier
A/D Stimulus Isolation
Digital Stimulus Isolation


Digital Stimulus Isolation Amplifier  

Digital Stimulus Isolation Amplifier  

The Model 4D Digital Stimulus Isolation Amplifier (SIU) is a low-noise optical isolation amplifier design to optically isolate electrical stimulating currents.  

ZERO leakage current, high compliance (72 VDC), ZERO power on spikes (maintains short circuit across electrode when off), battery load test function, good step response.  

Theory of operation:  
Inputs: The input mode is digital. TTL or CMOS 0V to 5V. Input connector is isolated BNC.  
Output: Output is a current source. Therefore unit operates as a Digitally controlled Current Source. Output connector is also an isolated BNC.  
Range: Three output ranges are 0-0.1mA, 0-1mA or 0-10mA. The output is adjust with a 10-turn potentiometer where the value of the pot reflects the value of the output current when a digital pulse is applied. e.g. when the range is 0-1mA and the pot is set at 6 turns the output current will be 0.6mA during the time that the digital input is at a "high" logic level. The range is set from a three position toggle switch.  
Power: Powered by 10 9Volt alkaline batteries.  

Digital Stimulus Isolation Amplifier Specifications 
Input impedance Digital mode => N/A
Input voltage range  Digital mode => TTL/CMOS 0 - 5V 
Gain Digital mode => Adjustable in the ranges; 0-0.1mA, 0-1mA, 0-10mA
Output Double-ended, isolated from ground.
Output impedance  Greater than 10^6 ohms.
Output Compliance 72 VDC
Step response <10 microseconds (digital mode, output 5mA, load = 1Kohm). Note; rise time is highly a function of load and output current level.
Leakage current  ZERO
Isolation 2500 Volts
Dimensions 7.25" x 2.5" x 6.25"
Other features Low battery indicator with load test. Rack mount option.
Getting Instruments, Inc - 20030330