Voltage drive circuit, voltage drive apparatus and semiconductor-device testing apparatus
AssigneeAdvantest Corporation
InventorsShoji Kojima, Takashi Sekino
Life of this patent
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Abstract
A circuit includes a first current path formed by a resistance R2, a transistor Q2, a transistor Q5 and a resistance R5. When an input signal A is low, a current i4 flows through the first circuit and the circuit outputs a shift voltage shifted from a constant voltage. When the input signal is high, the circuit directly outputs the constant voltage VH. The circuit further includes a second current path formed by a resistance R3 and a transistor Q3. By running a simulation current through the second current path, the shift voltage is monitored by a comparator OP1, and the current i4 is adjusted.
Claims30
A voltage drive circuit generating a voltage in accordance with an input signal, comprising:
- an output voltage generator including:
- a current drive circuit having a current adjustable terminal;
- an output voltage generating transistor being switched on and off in accordance with said input signal;
- an output voltage generating resistance through which a current flows when said output voltage generating transistor is in a first operational state and being switched on;
- and
- an output point where an output voltage which is shifted from a predetermined voltage is generated by a voltage drop caused at both ends of said output voltage generating resistance;
- and
- an output voltage monitor including a comparator comparing said shifted output voltage with a predetermined expected voltage,
- wherein an output from said comparator is connected to said current adjustable terminal of said current drive circuit.
A voltage drive circuit generating a voltage in accordance with an input signal, comprising:
- an output voltage generator including:
- a first circuit generating a predetermined voltage and an output voltage which is shifted from said predetermined voltage in accordance with a value of said input signal;
- and
- an output point where said shifted output voltage is generated;
- and
- an output voltage monitor including:
- a second circuit generating a reference voltage whose ratio to said shifted output voltage is a predetermined value;
- and
- a comparator comparing said reference voltage with a predetermined expected voltage;
- wherein said shifted output voltage shifted by said output voltage generator is adjusted based on an output from said comparator.
A voltage drive apparatus comprising a first voltage drive circuit generating a voltage in accordance with a first input signal and a second voltage drive circuit generating a voltage in accordance with a second input signal:
- wherein said first voltage drive circuit comprises:
- a first output voltage generator including:
- a first current drive circuit having a first current adjustable terminal;
- a first output voltage generating transistor being switched on and off in accordance with said first input signal;
- an output voltage generating resistance through which a current flows when said first output voltage generating transistor is in a first operational state, said current flowing through said first current drive circuit;
- and
- a first output point where a first output voltage which is shifted from a predetermined voltage is generated by a voltage drop caused at both ends of said output voltage generating resistance, and
- a first output voltage monitor including a comparator which compares said shifted first output voltage with a predetermined first expected voltage, wherein an output from said comparator being connected to said first current adjustable terminal, and
- said second voltage drive circuit comprises:
- a second output voltage generator including:
- a second current drive circuit having a second current adjustable terminal;
- a second output voltage generating transistor being switched on and off in accordance with said second input signal;
- and
- a second output point where a second output voltage being shifted from a predetermined voltage is generated by a voltage drop caused at both ends of said output voltage generating resistance, by a current flowing through said output voltage generating resistance when said second output voltage generating transistor is in a first operational stat, said current flowing through said second current drive circuit, and
- a second output voltage monitor including a second comparator comparing said shifted second output voltage with a predetermined second expected voltage, an output from said comparator being connected to said second current adjustable terminal.
Dependencies are inferred from the claim text.