Gated integrators

The SR250 gated integrator is a versatile, high-speed NIM module designed to recover fast analogue signals from noisy backgrounds.

The SR250 consists of a gate generator, a fast gated integrator, and exponential averaging circuitry. The gate generator, triggered internally or externally, provides an adjustable delay from a few nanoseconds to 100 ms before it generates a continuously adjustable gate with a width between 2 ns and 15 μs. The gate delay can be set from the front panel or automatically scanned by applying a rear-panel control voltage. Scanning the gate allows the recovery of entire waveforms.

The fast gated integrator integrates the input signal during the gate. The output from the integrator is then formalised by the gate width to provide a voltage proportional to the average of the input signal during the sampling gate. This signal is further amplified and sampled by a low-droop sample-and-hold amplifier, and output via a front-panel BNC connector. The last sample output provides a shot-by-shot analysis of the signal and makes the instrument a particularly useful component in a computer data acquisition system.