| 摘要 |
An electronics module (FIG. 1, 30) requires two distinct voltage inputs (V1, V2) and can be damaged when the difference between the two voltages exceeds a maximum value during power up. Additionally the electronics module (30) can be damaged during a power down transition when the difference between the two voltages exceeds a maximum negative value. A voltage ratio control circuit (FIG. 8) which includes at least one diode (D1), a capacitor (C1) whose value is proportional to the product of the value of the second voltage source (V2) and the value of the sum of any decoupling capacitances (C2) divided by the difference between the two input voltages is used to reduce the difference between the two voltages. This prevents damage to the electronic module (FIG. 1, 30) during power up and power down transitions caused by excessive voltage differences in the two voltage inputs (V1 and V2).
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