| 摘要 |
<p>An analog switching circuit may be implemented with MESFETs without forward biasing the switching device, and is applicable to JFET switches in general. Switching currents are provided from a nominal input line (20) which closely tracks the true analog input voltage, but is segregated therefrom. A current supply (E1) fed from the nominal input line (20) provides transient charging current to the gate of the switching transistor (M1) during the switching transition from OFF to ON states. Voltage setting devices (D1, R1, D2, R2) hold the gate and source of the enhancement-mode current supply (E1) at approximately the nominal supply voltage level when the switching transistor (M1) is ON, while a control section (D3, E3, D4, E4) holds the gate and source of the current supply device (E1) at a negative reference voltage level (V<->) when the switching transistor (M1) is OFF. In either case, the current supply device (E1) is inhibited from delivering gate current to the switching transistor (M1) during steady state operation.</p> |
