Abstract: In a circuit for supplying a load with a direct voltage, a diode is connected in a current path for supplying the load, a step-up converter is connected in the current paths parallel with the diode, and a control unit drives the step-up converter according to predetermined criteria in order to supply the load at least partially via the step-up converter. Such a circuit has advantageous power consumption characteristics. In comparison to conventional circuits that require an expensive filter, this circuit is more economical and/or has a smaller structural size.

Abstract: A driver circuit for a semiconductor test system generates test signals having predetermined voltage levels without being affected by stray capacitances.

Abstract: A multi-level driver circuit comprises: (a) an output buffer; (b) a first switch for applying a first analog level to the output buffer when in a closed state; (c) a second switch for applying a second analog level to the output buffer when in a closed state; (d) a third switch for applying a third analog level to the output buffer when in a closed state, wherein the third switch applies to the output buffer a capacitance which is dependent upon level when the third switch is in an open state and is unclamped; and (e) a clamping circuit for clamping the third switch such that the third switch applies to the output buffer a capacitance which is substantially independent of the third analog level when the third switch is in an open state and is clamped by the clamping circuit. The switches can be solid-state switches, such as diode bridges. Any number of switches can be provided, and more than one of the switches can be provided with a clamping circuit.

Abstract: A driver circuit for a semiconductor test system significantly reduces power consumption and limits current flowing from a power-supply. The driver circuit provides a test signal having predetermined voltage levels to a semiconductor test under test by switching diode bridges connected with high and low reference voltages. When receiving a switching signal, transistor circuits drive the diode bridge so that a test signal having the reference voltage is supplied to an output driver through the selected diode bridge. The output driver then supplies the test signal to the semiconductor device under test. The transistor circuits drive the diode bridge by supplying bridge current to ON/OFF control the diode bridges. Each of the diode bridges has a plurality of diodes connected symmetrically and an output of the diode bridge is taken from a point shifted by one diode from a center the diode bridge.