The general switch electric capacity electric charge pump type voltage switch can transform a positive voltage source voltage into the negative voltage, or causes it to double. But, certain (emitter-coupled logic) the electric circuit is composed completely by ECL equipment. Can only provide a negative voltage, like - 5.2V. Figure 1 explained how uses a switch electric capacity switch to obtain a being suitable is the ECL-TTL level switch and other electric circuit power supply positive electricity source voltage.
Although receives IC1 the segment as if to tie hands behind the back, but the IC1 interior switch’s bidirectional characteristic permission serves as the IC1 output foot the power source input end. When the IC1 internal switch the CAP foot earth, and meets through output foot OUT the CAP- foot to the negative supply, electric capacity C1 obtains the electric charge. In the second half cycle, IC1 earths CAP-, and meets CAP to (serves as generally input end), thus transmits the C1 positive charge for output capacity C3 and the load. In FSEL connects OUT in the situation, internal neterodyne electric charge electric discharge cyclic frequency hypothesis for approximately 1MHz.
As shown in Figure 2, the IC1 cut switch has the interface resistance, will have the influence output voltage scope, this output voltage scope will be lower than the input voltage, and when the output load electric current will increase will obtain not greatly ideal adjustment. In order to achieve the optimum performance, C1, input output bypass capacitor C2 and C3 must use the ESR small capacitor.
