| 摘要 |
<p>Spectrometers often use a so called charge balance photodiode array. This type of photodiode array uses parallel A/D conversion in each channel of said photodiode array, whereby a charge provided by a photocurrent (Iph) is accumulated at a integrator circuit (35) and a dumping circuit (37) removes this charge by well defined charge packets to keep the system in balance. In order to expand the field of application of these photodiode arrays, a storage circuit is inserted to buffer a possible charge overflow caused by a light beam (2) of high intensity, as often occurs when flash light lamps are used in the spectrometers. The storage circuit comprises a capacitor (Cs) a current limiter (32) which linearly conducts the photocurrent (Iph) below a process limit defined by the saturation limit of the dumping circuitry (37) and which, above this limit, converts a photocurrent pulse into a constant overflow current (Iin) having a duration corresponding to the amplitude of the photocurrent pulse (Iph). <IMAGE></p> |
