The ADA400A Differential Preamplifier allows direct oscilloscope measurements of very low amplitude voltages and signals which are not ground referenced. The high impedance of both inputs eliminates the need to add additional ground points in the DUT, thereby avoiding circulating currents which disturb the measurement or the circuit. The high gain and extremely high common mode rejection of the ADA400A Differential Preamplifier provide usable measurements of voltages as low as 5 μV, even in high-noise environments. Selectable bandwidth limiting reduces normal mode noise from digital logic, switch mode power supplies, and line frequency sources. Adjustable differential offset allows the user to null out transducer bridge bias and galvanic potential from the test setup. An "infinite impedance" mode can be selected in the two highest gain ranges allowing accurate measurements of signals with high source impedance.

Key performance specifications
10 μV/div sensitivity
Typically 100 dB CMRR DC to 10 kHz
Key features
Active differential preamplifier
Integral probe power with TEKPROBE™ BNC
Connectivity
The ADA400A is powered directly from TDS400, TDS500, TDS600, TDS700, TDS5000, TDS7000 (TEKPROBE), TDS7000 (TekConnect) w/ TCA-1MEG Series oscilloscopes.
The ADA400A may also be powered by a 1103 Probe Power Supply.
Applications
Mechanical analysis
Audio design
Biomedical research (not certified for patient connection)
Medical equipment (not certified for patient connection)
Gain settings
100x, 10x, 1x, 0.1x
CMRR
≥100,000: 1 DC - 10 kHz

Tektronix ADA400A differential preamplifier