Delta Developments

Fast, Screened Amplifiers

These Amplifiers were originally designed specially for Photon-Drag Detectors for CO2 TEA Lasers, but can, of course, be used for any general purpose amplification requirement. They have been carefully designed to eliminate noise from all sources and are mounted in an ultra screened box thus minimising pick up from the laser HV discharge or from transients from the AC mains supply.

The battery state is monitored continuously and on board regulation ensures that the performance remains constant as it discharges. Any reflections back from the oscilloscope are absorbed because the amplifiers are reverse terminated (that is, the output impedance is exactly 50Ω).

Amplifiers for Photon Drag Detectors
Fast Amplifier Specifications
Model A3 A10 A100
Gain X 3.1 X 10 X 100
Polarity Non-inverting Non-inverting Inverting
Input Imp. (BNC) 50Ω 50Ω 50Ω
Output Imp. (BNC) 50Ω 50Ω 50Ω
Rise-time (10-90%) 1.4ns 2.3ns 4.5ns
Freq. Band 6kHz - 240MHz 6kHz - 140MHz 12kHz - 70MHz
Gain-Bandwidth 700 MHz 1.4GHz 7GHz
Output Swing +500mV,-500mV +160mV, -90mV -150mV, +50mV
Input Noise (RMS) <35µV <30µV <30µV
Size 75x80x60mm 75x80x60mm 75x80x60mm
Batteries 2x PP3 (9V) 2x PP3 (9V) 2x PP3 (9V)
Battery Life 20hrs 35hrs 20hrs

Ultra Low Noise Amplifiers

These very low noise amplifiers are designed for Thermopiles, Calorimeters etc. Being battery powered they are virtually immune from 50/60Hz pick-up due to earth loops. The battery state is continuously monitored.

Input impedance is 30kΩ. Input bias current 10-20µA.