Clamping circuit to a reference voltage for ultrasound applications
AssigneeSTMicroelectronics S.r.l.
InventorsSandro Rossi, Davide Ugo Ghisu, Antonio Ricciardo
Life of this patent
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Abstract
A clamping circuit includes a clamping core connected to an output terminal and having a central node connected to a voltage reference and at least one first and one second clamp transistor, connected to the central node and having respective control terminals, the clamping core being also connected at the input to a low voltage input driver block. The clamping core includes a first switching off transistor connected to the output terminal and to the first clamp transistor, as well as a second switching off transistor connected to the output terminal and to the second clamp transistor.
Claims26
A high-voltage clamping device, comprising:
- an output;
- an input configured to couple to a reference voltage;
- a first clamping transistor;
- a second clamping transistor;
- a first switching transistor coupled between the output and the first clamping transistor;
- and
- a second switching transistor coupled between the output and the second clamping transistor, wherein,
- the first and second clamping transistors are high-voltage MOS transistors of complementary types;
- the first clamping transistor is coupled between the first switching transistor and the input, the first clamping transistor and the first switching transistor having body diodes coupled together in anti-series;
- and
- the second clamping transistor is coupled between the second switching transistor and the input, the second clamping transistor and the second switching transistor having body diodes coupled together in anti-series.
A system, comprising:
- a voltage clamping core, including:
- an output;
- an input configured to couple to a reference voltage;
- a first clamping transistor;
- a second clamping transistor;
- a first switching transistor coupled between the output and the first clamping transistor;
- and
- a second switching transistor coupled between the output and the second clamping transistor, wherein,
- the first and second clamping transistors are high-voltage MOS transistors of complementary types;
- the first clamping transistor is coupled between the first switching transistor and the input, the first clamping transistor and the first switching transistor having body diodes coupled together in anti-series;
- and
- the second clamping transistor is coupled between the second switching transistor and the input, the second clamping transistor and the second switching transistor having body diodes coupled together in anti-series;
- and
- a switching transistor driving block configured to generate driving signals to close said first and second switching transistors when said clamping core is active.
A transmission channel, comprising:
- means for clamping an output of the transmission channel to a reference voltage;
- anti-charging means coupled to the means for clamping.
The transmission channel of clam 18 wherein the means for clamping comprises first and second MOS clamping transistors and the anti-charging means includes a first MOS switching transistor coupled to the first MOS clamping transistor with body diodes coupled together in anti-series and a second MOS switching transistor coupled to the second MOS clamping transistor with body diodes coupled together in anti-series.
A method, comprising:
- transmitting a series of high-voltage pulses through a transmission channel;
- and
- clamping an output of the transmission channel to a reference voltage between pulses, the clamping including,
- closing a first switching MOS transistor coupled between a first clamping transistor and the output, wherein the first clamping transistor is coupled between the reference voltage and the first switching transistor;
- and
- closing a second switching MOS transistor coupled between a second clamping transistor and the output, wherein the second clamping transistor is coupled between the reference voltage and the second switching MOS transistor.
Dependencies are inferred from the claim text.