Circuit parameter calculations for a stepped-voltage reference generator

Summary

The above relationships make a rational approach to the selection of the generator circuit parameters possible, and provide its operating frequency range.

In addition,conclusions can be drawn about the basic conditions of the practical application of the above circuit:

• 1. When a small individual error in the steps is required, their numbern should be large, but the height of each step V₀ should be small.

• 2. In order to make the error due to the deviation of the gain from unity small, it is necessary to make C₁≪C₂ and hence, E≫V₀.

• 3. In order to obtain a high precision of the output voltage, it is necessary to obtain a correspondingly high precision and stability of the pulse E amplitude. A high stability of the pulse repetition frequency is not required. The source of E pulses must have a relatively low internal impedance; otherwise capacitor C₁ will not have enough time to recharge completely during the interval between pulses.

• 4. The “diode pump” circuit should only be used as a reference voltage source if the pulse repetition frequency is sufficiently high. Otherwise the error due to the discharge of capacitor C₂ in its load will be too large.