Abstract:
A transmission channel (1) is described of the type comprising at least one high voltage buffer block (4) comprising buffer transistors (MB1, MB2, MB3, MB4) and respective buffer diodes (DB1, DB2, DB3, DB4), being inserted between respective voltage references (HVPO, HVP1, HVMO, HVM1), these buffer transistors (MB1, MB2, MB3, MB4) being also connected to a clamping block (5), in turn comprising clamping transistors (MC1, MC2) connected to at least one output terminal (HVout) of this transmission channel through diodes (DC1, DC2) connected to prevent the body diodes of the clamping transistors (MC1, MC2) from conducting. Advantageously according to the invention, the transmission channel (1) comprises at least one reset circuit (20) comprising diodes (DME1, DME2, DME3, DME4) and being inserted between circuit nodes (XME1, XME2, XME3, XME4, XC1, XC2) of the high voltage buffer block (4) and of the clamping block (5), these circuit nodes (XME1, XME2, XME3, XME4, XC1, XC2) being in correspondence with conduction terminals of the transistors (MB l, MB2, MB3, MB4; MC1, MC2) comprised into the high voltage buffer block (4) and into the clamping block (5).
Abstract:
A switching circuit (30) is described being inserted between a connection terminal (Xdcr) and an output terminal (LVout) of a transmission channel (1) and of the type comprising at least one first and one second switching transistor (MSW1, MSW2) which are high voltage MOS transistors of complementary type inserted, in series to each other and by having respective equivalent or body diodes (DSW1, DSW2) in anti-series, between the connection terminal (Xdcr) and the output terminal (LVout). Advantageously according to the invention, the switching circuit comprises at least one bootstrap circuit (31) connected to respective first and second control terminals (XG1, XG2) of these at least one first and one second switching transistor (MSW1, MSW2), as well as to respective first and second voltage references (VDD_P, VDD_M) and having values of parasite capacities between these first and second control terminals (XG1, XG2) and at least one first and one second bootstrap node (XB1, XB2) of at least one order of magnitude lower with respect to the gate-source capacities (Csw1, Csw2) of these at least one first and one second switching transistor (MSW1, MSW2).
Abstract:
It is described a driving circuit (1) having at least one output terminal (OUT) connected to an ultrasonic pulse generator circuit and providing thereto with an output voltage (Vout), characterized in that it comprises at least one first portion (2A) connected to a first voltage reference (VPH) and including at least one first output transistor (MOP) being inserted between the first voltage reference (VPH) and the output terminal (OUT), such a first portion (2A) further comprising: at least one first high voltage comparator (3A) being connected to said output terminal (OUT) and to a first threshold voltage reference (VTHP), at least one first start-up circuit (4A) being controlled by a first setting signal (SETP); at least one first switching ON /OFF circuit (5A) being connected at its input to the first start-up circuit (4A), in correspondence with a first internal circuit node (XP), and to the first high voltage comparator (3A), in correspondence with a second internal circuit node (YP), and at its output to a control terminal of the first output transistor (MOP); the first start-up circuit (4A) providing a switching on signal (ONA) to the first switching on/ off circuit (5A) while the high voltage comparator (3A) provides a switching off signal (OFFA) to the first switching on/ off circuit (5A) which causes the switching off of the output transistor (MOP), the high voltage comparator (3A) generating the switching off signal (OFFA) when the output voltage (Vout) reaches a first desired supply voltage value which depends on the value of the first threshold voltage reference (VTHP).
Abstract:
A transmission channel (1) is described comprising at least one high voltage buffer block (4) comprising buffer transistors (MB1, MB2, MB3, MB4) and respective buffer diodes (DB1, DB2, DB3, DB4), being inserted between respective voltage references (HVP0, HVP1, HVM0, HVM1), a clamping circuit (10) being connected to a first output terminal (HVout) of the transmission channel (1), an antinoise block (6) being connected between the first output terminal (HVout) and a connection terminal (Xdcr) of the transmission channel (1); as well as a switching circuit (30) being inserted between the connection terminal (Xdcr) and a second output terminal (LVout) of the transmission channel (1). Advantageously according to the invention, the clamping circuit (10) comprises a clamping core (11), a reset circuit (20) comprising diodes (DME1, DME2, DME3, DME4 ) inserted between circuit nodes (XME1, XME2, XME3, XME4, XC1, XC2) of the high voltage buffer block (4) and of the clamping circuit (10), the circuit nodes (XME1, XME2, XME3, XME4, XC1, XC2 ) being in correspondance with conduction terminals of said transistors (MB1,MB2,MB3,MB4,MC1,MC2) comprised into the high voltage buffer block(4) and into the clamping circuit (10), and a switching circuit (30).
Abstract:
The invention relates to a High Voltage switch configuration (10) having an input terminal (IN) which receives an input signal (Vin) to drive a load and an output terminal (OUT) which issues an output signal (Vout) to the load. Advantageously according to the invention, the High Voltage switch configuration ( 10) comprises at least a first and a second diode (D1, D2), being placed in antiseries between said input and output terminals (IN, OUT) and having a pair of corresponding terminals in common, in correspondence of a first internal circuit node (Xc1).
Abstract:
A switching circuit (10) for an ultrasound transmission channel (1) is inserted between a connection terminal (Xdcr) and a low voltage output terminal (LVout) and comprising a receiving switch (30) a high voltage clamp circuit (HV1) inserted between the connection terminal (Xdcr) and a central node (Vc), a low voltage clamping switch (25) inserted between said central node (Vc) and a reference voltage (GND), the receiving switch (30) being low voltage and being inserted between the central node (Vc) and the low voltage output terminal (LVout), the clamping switch (25) and the receiving switch (30) being controlled in a complementary way with respect to each other. A transmission channel ( 1) for ultrasound applications is also described comprising at least such a switching circuit (10) and a process for driving said switching circuit (10).
Abstract:
A clamping circuit (10) to a voltage reference (GND) is described, of the type comprising at least one clamping core (11) connected to an output terminal (HVout) and having a central node (XC) connected to the voltage reference (GND) and in turn including at least one first and one second clamp transistor (MC1; MC2), connected to the central node (XC) and having respective control terminals (XG1, XG2), the clamping core (11) being also connected at the input to a low voltage input driver block (13). Advantageously according to the invention, the clamping core (11) further comprises at least one first switching off transistor (MS1) connected to the output terminal (HVout) and to the first clamp transistor (MC1), as well as a second switching off transistor (MS2) connected to the output terminal (HVout) and to the second clamp transistor (MC2), these first and second clamp transistors (MC1, MC2) being high voltage MOS transistors of complementary type and these first and second switching off transistors (MS1, MS2) being high voltage MOS transistors of complementary type and connected to the first and second clamp transistors (MC1, MC2) by having the respective equivalent or body diodes in anti-series so as to close themselves when the clamping circuit (10) is active and to sustain positive and negative high voltages when the clamping circuit (10) is not active.
Abstract:
The invention relates to a driving method for obtaining a linear gain variation of a transconductance amplifier, of the type comprising at least one differential transistor cell, with adjustment of a driving voltage value (Vtgc1) of a degenerative driving transistor (MD1) of said transconductance amplifier, comprising the steps of : generating an output current signal of a differential cell (11) being a copy of said differential transistor cell of said transconductance amplifier, said output current signal having a linear relationship with a transconductance value of said copy differential cell (11) as said driving voltage (Vtgc1) varies; generating a reference current signal having a linear relationship with a differential input voltage; comparing said output current signal and said reference current signal for adjusting said driving voltage value (Vtgc1) and modifying said transconductance value of said copy differential cell (11) up to a balance of said current signals.
Abstract:
Gate driver circuit for a half bridge or full bridge output driver stage, identifying a high side branch connected to one or more high side transistors (Mp) and a low side branch connected to one or more low side transistors (Mn), comprising a high side gate driver (10; 21p) and a low side gate driver (10n; 21n) receiving input signals at a low voltage level (VDD) and operating with a high voltage level (VPP), outputting signals at a high voltage level as gate driving signals (Gp, Gn) for the high side transistors (Mp) and low side transistors (Mn) In the solution described the high side and the low side branches of the gate driver (11) include each a set-reset latch (24p, 24n) which signal output (Qp, Qpn) is fed as gate signal to the corresponding transistor (Mp, Mn) of the half bridge or full bridge driver (11), a differential capacitive level shifter circuit (23p, 23n) receiving said input signals at a low voltage level and outputting high voltage signals to drive the set (S) and reset (R) inputs of the set-reset latch (24p, 24n).