EFFICIENCY IMPROVEMENT FOR BATTERY SAVER SLEEP MODE
Original Publication Date: 1991-Dec-01
Included in the Prior Art Database: 2001-Dec-24
During inactive receiver standby mode selective cir- cuits are placed in a sleep or off mode (much lower or zero current drain), to conserve battery extending the operation time. A preferred method of reducing or eliminating a circuits battery drain is to open the current drain path without discharging supply lime bypass capacitors. The energy used to initially charge the supply bypass is Ec = ;CV* Joules Where: C = capacitance in Farads V = the voltage across the capacitor electrodes This can be accomplished with a series switching transistor or removal of transistor biasing. When a series switch cannot be provided, the circuit current is reduced by disconnecting the supply. Figure 1, is an example using supply switching as a means of putting the circuits in a sleep mode. The regulator function is switched off and the charge on Cl is discharge through the circuit to ground.