The model CA5351 programmable current amplifier is a current input-voltage output preamplifier with variable gain. It achieves a measurement system with both high gain and wide bandwidth, which cannot be found anywhere else. Resonance does not occur even in the presence of cable or sensor capacitance because of its unique input circuit design and technology. And there is no overshoot or ringing in the response of pulse input as well. With high gain, wide bandwidth, fast response and low noise features, the model CA5351 is an ideal solution for a variety of small current measurements.