Voltage translating control structure
A voltage translating control structure for switching logic is described. A battery drain problem is corrected by this structure. The voltage translating feature allows reliable switching between power supply and battery even if the power supply voltage has significantly decreased. Operation is adaptable to include all DC power systems. Logic circuitry that also allows voltage translation is presented.
1. A voltage translating control structure operable to control switching
from a primary voltage reference to a battery voltage reference with no drain on the battery voltage reference, comprising:
a transistor operable to enable switching to the battery voltage reference; and
a level translating structure to control the transistor; and
wherein the level translating structure is operable to present to the control terminal of the transistor only those signals which are referenced to the battery voltage reference.
2. The voltage translating control structure of claim 1 , wherein:
the level translating structure accepts a plurality of logic inputs with each logic input referenced to either the primary voltage reference or to the battery voltage reference.
3. The voltage translating control structure of claim 1 , further comprising:
a plurality of inverters coupled in a feedback arrangement of the level translating structure translate binary input switch states to output states referenced to the battery voltage reference.
4. The voltage translating control structure of claim 1 , further comprising:
a plurality of transistors are utilized to couple logic inputs at the input of the voltage translating control structure to circuitry of the voltage translating control structure.