Gate controller for a charge pump converter

Provided is a gate controller having a primary signal input which is AC coupled to the gate through a capacitor, one or more bias inputs each connected to the gate through a resistor such as to control the DC voltage bias of the gate and therefore the conductivity of the switching element. The bias inputs can be properly connected to internal nodes of the charge pump, or charge pump stages, such that the gate controller is self-biased, without using bias-reference external to the charge pump. The gate controller can be made programmable by using potentiometers in place of the bias resistors. The programmable gate controller stages can be connected to form a programmable gate controlled charge pump.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a National Stage of International Application No. PCT/EP2020/081172 filed on Nov. 5, 2020, claiming priority based on European Patent Application No. 19207239.5 filed on Nov. 5, 2019.

TECHNICAL FIELD

The present invention relates to the field of charge pump converter and in particular of a stage of charge pump converter. More specifically, this invention deals with gate controller for a charge pump converter stage.

STATE OF THE ART

Charge pump is well known in the art, however, the active device, and more particularly the transistor, in diode configuration, is not controllable and as a consequence the charge pump input impedance and efficiency are largely dependent on the active device threshold voltage which varies with process corners and temperature.

The present invention discloses a gate controller for a charge pump converter stage, to control the gate bias voltage of the active device in a charge pump such that the charge pump input impedance and efficiency are more constant across process and temperature variations.

SUMMARY OF THE INVENTION

The present invention relates to a charge pump converter stage comprising at least one primary gate controller and at least one secondary gate controller; said at least one primary gate controller comprises at least one;primary signal output: said at least one primary signal output is configured to be connected to an at least one second primary signal input of a charge pump converter stage and/or a first circuit;first primary signal input: said at least one first primary signal input is configured to receive a first control signal;primary bias input: said at least one primary bias input configured to establish a voltage value and/or a current value of said at least one primary gate controller;second primary signal input: said at least one second primary signal input configured to be connected to an at least one primary signal output of a charge pump converter stage and/or to receive a main signal, preferably from an antenna, from an integrated circuit, at least one primary signal and/or from a charge pump converter stage; and,said at least one secondary gate controller comprises at least one:secondary signal output: said at least one secondary signal output is configured to be connected to an at least one second secondary signal input of a charge pump converter stage and/or a second circuit;first secondary signal input: said at least one first secondary signal input is configured to receive a second control signal;secondary bias input: at least one secondary bias input configured to establish a voltage value and/or a current value of said at least one secondary gate controller; and,second secondary signal input: said at least one second secondary signal input configured to be connected to an at least one secondary signal output of a charge pump converter stage and/or to receive said main signal, preferably from an antenna, from an integrated circuit, at least one secondary signal and/or from a charge pump converter stage;said at least one first primary signal input is configured to be connected to said at least one secondary signal output and said at least one first secondary signal input is configured to be connected to said at least one primary signal output.

Thanks to the arrangement according to the invention, the charge pump converter stage allows adjusting the bias voltage of the gate by coupling the gate of the switching element to the output of the previous charge pump converter stage and said at least one bias input, which sets the DC gate's voltage reference bias.

More specifically, the present invention comprises a gate controller having a primary signal input, a gate, one or more bias input each connected to the gate through a resistor or a transistor such as to control the DC voltage bias of the gate and therefore the conductivity of the switching element.

Said bias inputs can be properly connected to internal nodes of the charge pump, charge pump stage, or charge pump converter stage, such that the gate controller is self-biased without using bias-reference external to the charge pump.

Said gate controller can be made programmable by using potentiometers in place of the bias resistors.

According to an embodiment, said charge pump converter stage comprises at least one primary attenuator; said at least one primary attenuator comprises at least one primary attenuator input, at least one primary attenuator output and a ground.

According to an embodiment, said at least one primary attenuator input is configured to be connected to said at least one first primary signal input and said at least one primary attenuator output is configured to be connected to said at least one secondary signal output.

Thanks to one of those the arrangements according to the invention, said at least one primary signal may be attenuated or amplified through said at least one primary attenuator.

According to an embodiment, said charge pump converter stage comprises at least one secondary attenuator; said at least one secondary attenuator comprises at least one secondary attenuator input, at least one secondary attenuator output and a ground or said ground.

According to an embodiment, said at least one secondary attenuator input is configured to be connected to said at least one first secondary signal input and said at least one secondary attenuator output is configured to be connected to said at least one primary signal output.

Thanks to one of those the arrangements according to the invention, said at least one secondary signal may be attenuated or amplified through said at least one secondary attenuator.

According to an embodiment, said charge pump converter stage comprises at least one primary trim input configured to trim said at least one primary attenuator and/or said at least one secondary attenuator, and/or at least one secondary trim input configured to trim said at least one primary attenuator and/or said at least one secondary attenuator.

Thanks to the arrangement according to the invention, the attenuation or the amplification of said at least one primary signal and/or said at least one secondary signal may be trimmed through said at least one first secondary trim input and/or said at least one second secondary trim input.

According to an embodiment, said at least one primary attenuator comprises at least one first primary capacitor connected between said at least one primary attenuator input and said at least one primary attenuator output, and at least one second primary capacitor connected between said at least one primary attenuator output and said ground, and/or said at least one secondary attenuator comprises at least one first secondary capacitor connected between said at least one secondary attenuator input and said at least one secondary attenuator output, and at least one second secondary capacitor connected between said at least one secondary attenuator output and said ground.

According to an embodiment, said at least one primary trim input is configured to control the capacitance of said at least one second primary capacitor and/or the capacitance of said at least one second secondary capacitor.

According to an embodiment, said at least one secondary trim input is configured to control the capacitance of said at least one first primary capacitor and/or the capacitance of said at least one first secondary capacitor.

Thanks to one of those the arrangements according to the invention, the control on the K factor is made by trimming the values of said at least one first primary capacitor, said at least one second primary capacitor, said at least one first secondary capacitor and/or said at least one second secondary capacitor in said charge pump converter stage. Indeed, since it exists an optimal k-factor for each process and temperature, the charge pump converter stage efficiency can be in this way maximized over process and temperature.

According to an embodiment, said at least one primary gate controller comprises at least one primary switching element having a primary conduction path with a first primary terminal and a second primary terminal, and a primary gate configured to control the current flowing through said primary conduction path, said primary conduction path being configured to provide said at least one primary signal; said primary gate is configured to be connected to said at least one first primary signal input and to said at least one primary bias input, and/or wherein said at least one secondary gate controller comprises at least one secondary switching element having a secondary conduction path with a first secondary terminal and a second secondary terminal, and a secondary gate configured to control the current flowing through said secondary conduction path, said secondary conduction path being configured to provide said at least one secondary signal; said secondary gate is configured to be connected to said at least one first secondary signal input and to said at least one secondary bias input.

Thanks to the arrangement according to the invention, the charge pump converter stage allows adjusting the bias voltage of the gate by coupling the gate of the switching element to the output of the previous charge pump converter stage and said at least one bias input, which sets the DC gate's voltage reference bias.

According to an embodiment, said at least one primary bias input comprises a plurality of primary bias current flow controller comprising at least one first primary bias current flow controller and/or at least one first primary bias transistor and/or wherein said at least one secondary bias input comprises a plurality of secondary bias current flow controller comprising at least one first secondary bias current flow controller and/or at least one first secondary bias transistor.

Thanks to the arrangements according to the invention, the conduction path of the switching element may be controlled.

According to an embodiment, said at least one primary bias input is configured to be connected to said at least one second primary signal input, and/or said at least one secondary bias input is configured to be connected to said at least one second secondary signal input.

Thanks to the arrangements according to the invention, the conduction path of the switching element may be controlled.

The present invention relates to a charge pump converter comprising a plurality of charge pump converter stages including at least one first charge pump converter stage according to any precedent claims, and a second charge pump converter stage according to any precedent claims; said at least one first primary signal input of said at least one first charge pump converter stage is directly connected to said at least one first primary signal input of said at least one second charge pump converter stage, said at least one first secondary signal input of said at least one first charge pump converter stage is directly connected to said at least one first secondary signal input of said at least one second charge pump converter stage, said at least one primary signal output of said at least one first charge pump converter stage is directly connected to said at least one second primary signal input of said at least one second charge pump converter stage, said at least one secondary signal output of said at least one first charge pump converter stage is directly connected to said at least one second secondary signal input of said at least one second charge pump converter stage.

Thanks to the arrangements according to the invention, the charge pump converter stages are linked together.

According to an embodiment, said at least one primary trim input is configured to control the capacitance of said at least one second primary capacitor of said first charge pump converter stage, the capacitance of said at least one second secondary capacitor of said second charge pump converter stage, the capacitance of said first charge pump converter stage, and/or the capacitance of said second charge pump converter stage.

According to an embodiment, said at least one secondary trim input is configured to control the capacitance of said at least one first primary capacitor of said first charge pump converter stage, the capacitance of said at least one first secondary capacitor of said second charge pump converter stage, the capacitance of said first charge pump converter stage, and/or the capacitance of said second charge pump converter stage.

Thanks to one of those the arrangements according to the invention, the control on the K factor is made by trimming the values of said at least one first primary capacitor, said at least one second primary capacitor, said at least one first secondary capacitor and/or said at least one second secondary capacitor in said charge pump converter stage. Indeed, since it exists an optimal k-factor for each process and temperature, the charge pump converter stage efficiency can be in this way maximized over process and temperature.

DESCRIPTION OF THE INVENTION

Specific embodiments of the invention will now be described in detail with reference to the accompanying figures. Like elements in the various figures are denoted by like reference numerals for consistency. Further, the use of “Fig.” will be equivalent to the use of “figure” in the description.

The present invention relates to a charge pump converter stage100comprising at least one primary gate controller200and at least one secondary gate controller300as depicted inFIG.1. Said at least one primary gate controller200may comprise at least one primary signal output250, at least one first primary signal input230, at least one primary bias input220and at least one second primary signal input210.

Said at least one primary signal output250may be connected in series to a first circuit and/or an at least one second primary signal input210of a charge pump converter stage100. Indeed, said at least one second primary signal input210may be connected to, preferably directly connected to an at least one primary signal output250of a following charge pump converter stage100and/or to receive a main signal, preferably from an antenna, from an integrated circuit and/or from a charge pump converter stage100, and said at least one first primary signal input230may receive a first control signal and said at least one primary bias input220may establish a voltage value and/or a current value of said at least one primary gate controller200.

Further, said at least one primary gate controller200may comprise at least one primary switching element240having a primary conduction path245with a first primary terminal241and a second primary terminal242, and a primary gate243configured to control the current flowing through said primary conduction path245: said primary conduction path245may provide said at least one primary signal. By controlling, the skilled man in the art would understand that the current flowing through said primary conduction path245or said secondary conduction path345may be varied in amplitude, frequency, and/or in phase such as to be transmitted to another charge pump converter stage for instance as shown inFIG.7.

Said primary gate243may be also connected to, preferably directly connected to said at least one first primary signal input230preferably via at least one primary coupling capacitor231and to said at least one primary bias input220via at least one primary bias element221, like at least one first primary bias current flow controller221, as depicted inFIG.2for example. So, the charge pump converter stage allows adjusting the bias voltage of said primary gate243by coupling said primary gate243of the switching element to the output of the previous charge pump converter stage and/or said at least one bias input, which sets the DC gate's voltage reference bias.

Similarly to said at least one primary gate controller200, said at least one secondary gate controller300may comprise at least one secondary signal output350, at least one first secondary signal input330, at least one secondary bias input320and at least one second secondary signal input310. Said secondary gate343may be also connected to, preferably directly connected to said at least one first secondary signal input330preferably via at least one secondary coupling capacitor331and to said at least one secondary bias input320via at least one secondary bias element321, like at least one first secondary bias current flow controller321, as depicted inFIG.2for example.

Said at least one secondary signal output350may be connected in series to a second circuit an at least one second secondary signal input310of a charge pump converter stage100. Indeed, said at least one second secondary signal input310may be connected to, preferably directly connected to an at least one secondary signal output350of a following charge pump converter stage100and/or to receive said main signal, preferably from an antenna, from an integrated circuit and/or from a charge pump converter stage100, and said at least one first secondary signal input330may receive a second control signal, and said at least one secondary bias input320may establish a voltage value and/or a current value of said at least one secondary gate controller300. As shown inFIG.1, said at least one first primary signal input230may be connected to, preferably directly connected to said at least one secondary signal output350and said at least one first secondary signal input330may be connected to, preferably directly connected to said at least one primary signal output250.

Further, said at least one secondary gate controller300may comprise at least one secondary switching element340having a secondary conduction path345with a first secondary terminal341and a second secondary terminal342, and a secondary gate343configured to control the current flowing through said secondary conduction path345: said secondary conduction path345may provide said at least one secondary signal.

Said secondary gate343may be also configured to be connected to, preferably directly connected to said at least one first secondary signal input330, via at least one secondary coupling capacitor331, and to said at least one secondary bias input320. So, the charge pump converter stage allows adjusting the bias voltage of said secondary gate343by coupling the said secondary gate343of the switching element to the output of the previous charge pump converter stage and said at least one bias input, which sets the DC gate's voltage reference bias.

In order to adjust the bias voltage of the gates243,343, the gates243,343of the switching elements in said at least one primary gate controller200and said at least one secondary gate controller300may be coupled to the output of the previous charge pump converter stage and/or said at least one bias input220,320, which sets the DC gate's voltage reference bias. More specifically, the present invention may comprise said at least one primary gate controller200and said at least one secondary gate controller300having said primary gate243, said at least one primary bias input220connected to, preferably directly connected to said primary gate243through a bias element like a resistor or a transistor and said secondary gate343, said at least one secondary bias input320connected to, preferably directly connected to said secondary gate343through at least one primary bias element221and/or at least one secondary bias element321like a resistor or a transistor respectively such as to control the DC voltage bias of said primary gate243and said secondary gate343and therefore the conductivity of at least one primary switching element240and at least one secondary switching element340respectively. Said bias inputs, more precisely said at least one primary bias input220and said at least one secondary bias input320may be properly connected to, preferably directly connected to internal nodes of said charge pump converter stage100such that said at least one primary gate controller200and said at least one secondary gate controller300are self-biased without using bias-reference external to the charge pump. As it may be inFIG.2, where said at least one primary bias input220may be directly connected to, preferably directly connected to said at least one second primary signal input210, and said at least one secondary bias input320may be directly connected to, preferably directly connected to said at least one second secondary signal input310.

As previously mentioned, said bias element may be a resistor or a transistor. Indeed, said at least one primary bias input220may comprise at least one first primary bias current flow controller221, like at least one first primary bias transistor221. In some embodiments not represented, said primary gate243may be connected to, preferably directly connected to said second primary terminal242, rather said at least one primary signal output250via an at least one second primary bias current flow controller and/or at least one second primary bias transistor thus the primary conduction path245of the primary switching element240may be controlled. The same applies for the secondary switching element340with at least one first secondary bias current flow controller221, like at least one first secondary bias transistor221and at least one second secondary bias current flow controller like at least one second secondary bias transistor.

The applicant does not exclude the gate voltage of said primary gate243may be determined by configuration of said at least one first primary bias current flow controller221, like a resistor, and at least one second primary bias current flow controller, like a resistor, forming a resistive divider and the DC primary gate voltage may be comprised between the voltage value of said at least one second primary signal input210and of a second primary terminal242. The same applies for the secondary switching element340.

According to some embodiments not represented, instead of a resistor as said at least one first primary bias current flow controller221and/or as said at least one second primary bias current flow controller, a transistor and preferably by a MOS transistor may be used such as the primary conduction path245of the primary switching element240may be controlled and may make said charge pump converter stage100programmable and more specifically said at least one primary gate controller200programmable. The same applies for the secondary switching element340.

Further, said at least one first primary bias transistor221may be trimmed such as to control the current flowing through and/or said at least one first primary bias transistor221and/or wherein said at least one second primary bias transistor may be trimmed such as to control the current flowing through said at least one first primary bias transistor221. So, the primary conduction path245of the switching element240may be controlled which makes the charge pump converter programmable via an integrated circuit, a microcontroller and/or a processor. The same applies for the secondary switching element340.

The applicant may want to have a linear control of said charge pump converter stage100programmable and more specifically said at least one primary gate controller200programmable a potentiometer and/or the digital potentiometer may replace said transistor and preferably said MOS transistor in linear with a controlled channel resistance. Since the plurality of primary bias current flow controller may comprise at least one first primary bias transistor221and at least one second primary bias transistor, the conduction path245of the primary switching element240may be linearly controlled and may make the charge pump converter programmable via an integrated circuit, a microcontroller and/or a processor. The same applies for the secondary switching element340.

Moreover, since it exists an optimal k-factor for each process and temperature, in prior art, the charge pump efficiency999may vary uncontrollably as a function of temperature, for example. Whereas, the charge pump converter stage efficiency199, seeFIG.7, according the invention, can be maximized for a given process and temperature. In order to achieve this, said charge pump converter stage100may comprise at least one primary attenuator410and/or at least one secondary attenuator420.

As illustrated inFIGS.3and4, said at least one primary attenuator410may comprise a ground499, at least one primary attenuator input411configured to be connected to, preferably directly connected to said at least one first primary signal input230and at least one primary attenuator output412configured to be connected to, preferably directly connected to said at least one secondary signal output350, such as said at least one primary signal may be attenuated or amplified through said at least one primary attenuator410.

Similarly, said charge pump converter stage100may comprise said ground499, at least one secondary attenuator input421configured to be connected to, preferably directly connected to said at least one first secondary signal input330and at least one secondary attenuator output422configured to be connected to, preferably directly connected to said at least one primary signal output250, such as said at least one secondary signal may be attenuated or amplified through said at least one secondary attenuator420.

As shownFIGS.5and6, said at least one primary attenuator410may comprise at least one first primary capacitor413connected between said at least one primary attenuator input411and said at least one primary attenuator output412, and at least one second primary capacitor414connected between said at least one primary attenuator output412and said ground499. In other side, said at least one secondary attenuator420may comprise at least one first secondary capacitor423connected between said at least one secondary attenuator input421and said at least one secondary attenuator output422, and at least one second secondary capacitor424connected between said at least one secondary attenuator output422and said ground499.

In order to control the K factor and thus the attenuation and amplification of said at least one primary signal and/or said at least one secondary signal, the value or values of said at least one first primary capacitor413, said at least one second primary capacitor414, said at least one first secondary capacitor423and/or said at least one second secondary capacitor424may be trimmed via at least one primary trim input445and/or at least one secondary trim input435. Indeed, since it exists an optimal k-factor for each process and temperature, said at least one primary attenuator410and/or said at least one secondary attenuator420may be trimmed such as to attenuate or amplify said at least one primary signal and/or said at least one secondary signal and thus the charge pump converter stage efficiency may be maximized over process and temperature.

In order to attenuate or amplify said at least one primary signal and/or said at least one secondary signal, said charge pump converter stage100may comprise at least one primary trim input445configured to trim said at least one primary attenuator410and/or said at least one secondary attenuator420. It may be also possible that said charge pump converter stage100may comprise also at least one secondary trim input435configured to trim said at least one primary attenuator410and/or said at least one secondary attenuator420in order to achieve the attenuation or the amplification of said at least one primary signal and/or said at least one secondary signal.

So, the control on the K factor may be made by trimming the values of said at least one first primary capacitor413, said at least one second primary capacitor414, said at least one first secondary capacitor423and/or said at least one second secondary capacitor424in said charge pump converter stage100. Indeed, since it exists an optimal k-factor for each process and temperature, the charge pump converter stage efficiency can be in this way maximized over process and temperature.

As it may be observed inFIGS.5and6, said at least one primary trim input445may control the capacitance C414of said at least one second primary capacitor414and/or the capacitance C424of said at least one second secondary capacitor424. Similarly, said at least one secondary trim input435may control the capacitance C413of said at least one first primary capacitor413and/or the capacitance C423of said at least one first secondary capacitor423.

As example, the following formula describes a sinusoidal clock signal RFin(X) from said at least one first secondary signal input330:
RFin(X)=RFin0-pk·sin(2πft)

X being the number of said gate controller100, for example the third charge pump converter stage100would be written as follow: RFin(3).

Neglecting the stray capacitance, the input voltage of the third at least one primary gate controller200and at least one secondary gate controller300, rather the voltage of said at least one second primary signal input210, for example, could be written as:
OUT(3−1)=K·(3−1)·(2RFin0-pk−Vdiode)+K·RFin0-pk·sin(2πft)

and the gate voltage on said primary gate243of the 3rd gate controller100is:
G(3)=vbias3+RFin0-pk·sin(2πft)

Where K being an attenuation coefficient or an amplification coefficient of said at least one primary attenuator410, as previously mentioned:

Further, as early mentioned, said at least one primary bias input220can be properly connected to a bias-reference external to the charge pump or alternatively to an internal node of the charge pump, or charge pump stages, as shown onFIGS.2,4and6, such that said at least one primary gate controller200is self-biased without using bias-reference external to the charge pump.

As shown inFIG.8, a charge pump converter, according to another aspect of the invention, may comprise a plurality of charge pump converter stage100according to any precedent embodiment.

Said at least one primary gate controller200and said at least one secondary gate controller300are in differential and said at least one first primary signal input230of all charge pump converter stage100are connected to each other and said at least one first secondary signal input330of all charge pump converter stage100are also connected to each other, and said at least one second primary signal input210is connected to said at least one primary signal output250of a previous charge pump converter stage100. The same applies for said at least one secondary gate controller300, e.g. said at least one secondary signal output350is connected to an at least one second secondary signal input310of a previous charge pump converter stage100.

Thanks to the arrangement according to the invention, the charge pump converter stage allows adjusting the bias voltage of the gate by coupling the gate of the switching element to the output of the previous charge pump converter stage and said at least one bias input, which sets the DC gate's voltage reference bias.

More specifically, the present invention comprises a gate controller having a primary signal input, a gate, one or more bias input each connected to the gate through a resistor or a transistor such as to control the DC voltage bias of the gate and therefore the conductivity of the switching element.

Said bias inputs can be properly connected to internal nodes of the charge pump, charge pump stage, or charge pump converter stage, such that the gate controller is self-biased without using bias-reference external to the charge pump.