The circuit in the figure uses the four current amplifiers of the LM3900 to generate a sawtooth signal with 'extremely slow rise, in the order of 100 s / V. Two amplifiers are connected in cascade to obtain a high gain for the integrator. The charge current of the capacitor is low, of the order of 10 nA, which means that this component must not leak, so that the losses are not greater than this load, thus preventing the operation of the circuit. An insulation resistance of 100,000 M ohms, for example, means a leakage current of 0.1 nA, which increases rapidly with temperature and can already cause malfunctions. With the 1 uF capacitor used in the circuit, a scan rate of 100 s / V is obtained. The reset rate is 0.7 s / V
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