Single Channel Differential Amplifier

Overview:

The DP-301 Single Channel Differential Amplifier is an AC/DC differential pre-amplifier highly suited for EEG, EKG and extracellular recording.
 

Features:

• High input impedance
• High common mode rejection
• Low noise with high gain
• High tolerance to DC offsets
• Bandwidth filtering available

High Input Z, High CMR
High common mode rejection is very important in minimizing electrical interference. The high input resistance of the DP-301 (10¹² Ω typical) ensures that the instrument's high CMR will not be degraded by differences in source impedance at the input. This is important in extracellular recording, where the difference in resistance of the recording and indifferent electrode is often large.

High DC Tolerance
Extracellular action potentials are typically measured in microvolts but are usually accompanied by much larger DC electrode voltages. The DP-301 is designed to amplify these microvolt level events with as much as ±3 VDC at the input.

High Gain, Low Noise and Bandwidth Limiting
Gain selections of x100, x1000 and x10000. Microvolt signals are sufficiently amplified for computer data acquisition and recorder inputs. Noise is very low, typically 10 µV p-p at 1 Hz to 10 kHz bandwidth. Reducing the bandwidth with the low pass and high pass filters further lowers noise.

Calibration Signal
The internal Cal signal provides a convenient check of amplifier gain and operation.

Battery Powered/Portable
The single channel DP-301 is powered with 4 standard 9 V transistor batteries yielding approximately 500 hours of normal operation. The small size of the DP-301 makes it possible to be placed at the measurement site or inside a Faraday cage. End of battery life is indicated by the Low Bat light.

Input Cables
The standard IC-2S input cables (2 per channel) which are not terminated at the outboard end. Optionally available are cables with 2 mm pin and alligator clip (p/n IC-4M). There is no additional cost if specified at time of order.

Summary of Features:

• Single channel AC/DC pre-amplifier designed for amplifying weak signals such as EEG, EKG and extracellular action potentials
• Battery powered amplifier with very low noise of 10 µV peak-to-peak (1 Hz to 10 kHz with input shorted)
• High gain with selections of x100, x1000 and x10000. Thus microvolt level signals are sufficiently amplified for computer data acquisition and signal analysis
• Excellent common mode rejection of 100 dB min (100000:1) at 60 Hz with input resistance 10¹² Ω typical
• Both high pass and low pass filters, each with 4 switch settings
• DC offset of ±600 mV at output BNC operates in both AC or DC modes
• A front panel calibrate push button applies 1 mV pulse to the amplifier input to check intermediate gains and support equipment

Applications:

The Single Channel Differential Amplifier allows recording of EEG, EKG and extracellular recording which include:

• Single Unit Recording – records the electrical activity of a single one neuron with a small tip electrode 
• Multi-Unit Recording – records electrical activity generated by several neurons
• Field Potentials - records the field potential generated from indistinguishable activity generated by many cells
• Amperometry - records changes in the chemical composition of the oxidized components of a biological sample using a carbon electrode

For more information see the Extracellular Recordings and Neurophysiology application pages.

Specifications:

• Voltage Gain, AC/DC: x100, x1000 and x10000
• Input Resistance: 10¹² Ω typical
• Leakage Current: 50 pA typical
• Common Mode Rejection: 100 dB min (100000:1) at 60 Hz
• Noise, input shorted: 10 µV p-p, 1 Hz to 10 kHz
• Low Frequency Filter Settings (high pass): 0.1, 1.0, 10 and 300 Hz
• High Frequency Filter Settings (low pass): 0.1, 1.0, 3.0 and 10 kHz
• Calibration Signal:  1 mV p-p at 10 Hz
• Max. Common Mode Signal: ±3 V
• Output Voltage Swing:  ±10 V
• Output Resistance: 220 Ω
• Input and Output Connectors: BNC
• Power Requirements: 4 x 9 V alkaline batteries
• Physical Size: 8.8 x 20 x 17.5 cm (H x W x D)
• Shipping Weight: 2.3 kg
• Warranty: Two years, parts and labor (excluding batteries)