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 bs eliminates the need to add additional ground points in the DUT, thereby avoiding circulating currents which disturb the measurement or the circuit.
The ADA400A may also be powered by a 1103 Probe Power Supply.
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 bandb 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.
All specifications are guaranteed unless noted otherwise. All specifications apply to all models unless noted otherwise.
Signal ranges
| Gain setting | Common Mode signal range | Differential signal range 1 | Max offset |
|---|---|---|---|
| 100x | ±10 V | 0.1 V | ±1.0 V |
| 10x | ±10 V | 1 V | ±1.0 V |
| 1x | ±40 V | 10 V | ±40 V |
| 0.1x | ±40 V | 80 V | ±40 V |
1 For higher voltages, attenuating probes may be used, but CMRR perbance will be degraded.
Bandb limits100 Hz, 3 kHz, 100 kHz, full (≥1 MHz)Input impedance1 MΩ || ~ 55 pF (infinity Ω selectable in 100x and 10x gains)NoiseTypically ≤30 μVRMS at 100x gain (referred to b)
Ordering inbation
