Lecroy DA1850A High-performance Differential Amplifier, 100MHz

The Lecroy DA1850A is a differential amplifier delivering 100 MHz bandwidth for precision signal conditioning in measurement and analysis applications. It amplifies differential signals with selectable gains of 1 or 10, complemented by a built-in ÷10 attenuator for effective gains of 10, 1, or 0.1. The instrument achieves superior common mode rejection and ultralow input noise of less than 4 nV/√Hz at ×10 gain, making it ideal for signal integrity analysis, automotive testing, and power electronics characterization.

Technical Specifications

• Bandwidth: 100 MHz


• Amplifier gain: Selectable 1 or 10


• Input attenuator: ÷10 factor (effective gains of 10, 1, or 0.1)


• Common mode dynamic range: ±15.5 V (÷1 gain) or ±155 V (÷10 gain)


• Output limiting: ±500 mV to prevent oscilloscope overdrive


• Input protection: ±250 V with automatic disconnection of overvoltage signals (manual reset required)


• Input noise (×10 gain): Less than 4 nV/√Hz, broadband


• DC drift (×10 gain): 50 µV/°C


• Power requirements: 100–250 VAC line operation without switching

Key Features

• High common mode rejection ratio enabling measurement fidelity previously unobtainable with standard oscilloscopes


• Significantly improved overdrive recovery for D/A converter settling measurements at 14-bit (60 ppm) precision


• Microprocessor control (A versions) with sleep mode to eliminate digital noise during normal operation


• Retained front panel settings between power cycles


• Probe coding input for multi-attenuation probe compatibility and standard probe decoding

Typical Applications Signal integrity analysis, automotive electronics testing, power electronics characterization, and precision differential signal measurement in laboratory and field environments.

Compatibility & Integration The DA1850A integrates directly with compatible oscilloscopes, leveraging its high CMRR and low-noise characteristics to extend measurement capability beyond standard single-ended acquisition. Output is limited to ±500 mV, ensuring safe oscilloscope input protection.