Teledyne LeCroy DA1855A

1 Channel, 100 MHz Differential Amplifier with Precision Voltage Source

The DA1855A is a stand-alone, high-performance 100 MHz differential amplifier. It is intended to act as a signal conditioning preamplifier for oscilloscopes, digitizers and spectrum analyzers, providing differential measurement capability to instruments having only a single-ended input. When used with a DA1855A, oscilloscopes can obtain Common Mode Rejection Ratio (CMRR) and overdrive recovery performance levels previously unobtainable.

Amplifier gain can be set to 1 or 10. A built-in input attenuator can be separately set to attenuate signals by a factor of 10, providing gains of 10, 1, or 0.1 and common mode dynamic range of +/-15.5 V (÷1) or +/-155 V (÷10). Optional probes increase the maximum input signal and common mode ranges in proportion to their attenuation ratio but do not exceed their maximum input voltage rating. Effective gain of the DA1855A, including probe attenuation, amplifier gain and attenuator settings, is automatically displayed.

The DA1855A has a bandwidth of 100 MHz, but any one of the three 3-pole bandwidth limit filters can be selected to reduce bandwidth to 20 MHz, 1 MHz or 100 kHz to limit noise above the frequency of interest.

The DA1855A output is carefully limited to +/-500 mV, so that the oscilloscope is not overdriven by large inputs. This allows many oscilloscopes to directly measure the settling of D/A converters with 14-bit (60 ppm) precision, better than any other differential comparator.

The DA1855A features a built-in Precision Voltage Generator (PVG) that can be set to any voltage between +/-15.5 V (+/-10 V in Differential Offset) with up to 100 MicroV resolution. The PVGs output can be selected as an input to the inverting (-) input of the amplifier for operation as a differential comparator or applied internally as a true differential offset voltage. The PVG is also available for external use through a rear panel connector.

The DA1855A operates from 90 to 250 VAC line without line switching. High-performance differential probes such as the DXC100 ÷10/÷100 high CMRR probes are recommended.

Teledyne LeCroy DA1855A datasheet & specifications