| 摘要 |
A swtiching circuit for switching an input dc voltage of predetermined polarity is used, for example, for a synchronous dc-dc converter. The switching circuit is divided between a high side package (52) and a low side package (56) each having a logic input (90) and a switch (6, 8) connected between switching outputs (84, 86). The switching outputs (84, 86) of the high and low side packages (52, 56) are connected in series between input voltage terminals (4, 2). A pulse width modulator (18) is connected to the logic inputs (90) of the packages for supplying an alternating control signal for switching the high and low side switches (6, 8) alternately. Each of the high and low side packages (52, 56) contains logic circuitry (150) for controlling the respective switch (6, 8) based solely on the voltages on the respective logic input (90) and respective switching outputs (84, 86) to prevent teh switches (6, 8) in the high and low side packages (52,56) from conducting at the same time. The logic circuitry (150) may use a predermined delay or incorporate sense circuitry that switches based on teh voltage on the outputs. In this way, the need for control interconnections between the high and low side packages (52, 56) is avoided. |
