US 2008/0174360 A1 · Charge pump circuit for high voltage generation

Abstract

A circuit and method are given, to realize a high efficiency voltage multiplier for integrated circuits generating an internal and flexible positive or negative high voltage on-chip supply voltage from low external positive or negative supply voltages or ground. Applying multi-phase control signals to voltage boost internal nodes allows for eliminating threshold voltage drop losses and thus improves the voltage pumping gain compared to circuits with diode-configured FETs of prior art. Making use of voltage signals from antecedent stages in order to bias the bulk of MOS transistors fabricated in triple-well technology enables relaxing of the gate oxide stress within high order stage MOS transistors. Such a method, called leap-frog bulk potential tracking method, makes MOS transistors from different stages exhibit about the same body effect, which is very important because MOS transistors of higher order stages now show the same performance as MOS transistors from lower order stages. Important also in terms of efficiency as the charge sharing speed of high order MOS transistors always dominates the total charge pump performance and the driving force of pumped currents, thus also allowing for a greater number of serially connectable stages overall or a smaller number necessary for a certain targeted output voltage.

Claims48

Dependent claims

A charge pump circuit being driven by a first set of control clock signals and a second set of control clock signals, comprising:

a first circuit stage driven by said first set of control clock signals;
a second circuit stage driven by said second set of control clock signals;
the first circuit stage comprising a first transistor, a second transistor between two terminals of the first transistor, and a third transistor connected between the first circuit stage and the second circuit stage, the second circuit stage comprising a fourth transistor, a fifth transistor between two terminals of the fourth transistor, and a sixth transistor connected between the first circuit stage and the second circuit stage;
wherein the charge pump is operated by the first and the second set of control clock signals such that when the first transistor is fully turned on the third transistor is fully turned on.

1 more element

A circuit, realizing a Charge Pump (CP) for High Voltage Generation used for voltage multiplier devices and consisting of a basic circuit structure arranged in a, versus a virtual middle line, fundamentally symmetrical configuration and being controlled by a set of three multiphase pairs of control clock signals either as a first pair of complementary signals or as second and third pairs of signals each member signal of which is shifted by one half clock cycle versus its other member signal, comprising:

an input stage;
an output stage;
one or more of twin circuit block stages, each stage of an essential four-pole or two-port character i.e. each stage made up of a pair of circuit blocks each having an input terminal and an output terminal, apart from having two additional pairs of auxiliary terminals for each of said twin circuit blocks, which themselves are built as symmetrical items mirrored to each other, each of identical structure and layout and each consisting of the same number and kind of components;
one pair of parallel virtual rails provided for possible connections as lines between said input stage, one or more of said twin circuit blocks and said output stage and arranged symmetrically in parallel to said virtual middle line located in the middle between said pair of possible connection lines;
and
a consecutive series of an arbitrary number of pairs of main nodes being situated on said pair of possible connection lines arranged in such a way, that each pair of main nodes has one part of it allofted to each part of said pair of possible connection lines respectively.

3 more elements

A method for implementing a Charge Pump (CP) Circuit for High Voltage Generation device with multiphase control clock signals and with one or more CP-stages implemented as MOS transistor components and realized as an Integrated Circuit (IC) fabricated in MOS technology, comprising the steps of:

providing a basic circuit structure built up as a series connection of an initial stage and one or more following twin circuit block stages operating as CP-stages, each stage of an essential four-pole or two-port character wherein each stage has a pair of input terminals and a pair of output terminals, apart from additional pairs of auxiliary and pump signal terminals for each of the twin circuit blocks;
arranging said basic circuit structure in a, versus a virtual middle line, fundamentally symmetrical configuration exhibiting two parallel rails of virtual connection lines each endowed with a consecutive series of pairs of main nodes whereby all upper parts of said pairs located above said virtual middle line are designated as A-parts, all lower parts located below said virtual middle line as B-parts;
defining “connect directly” as connecting A-part items to A-part items and B-part items to B-part items as well as “connect cross-over” as connecting A-part items to B-part items and vice-versa;
and translating this terminology also to other possible actions;
furnishing a set of three pairs of multiphase control clock signals, whereby direct A-part signals are shifted by one half clock cycle compared to B-part signals or vice-versa by designation and each pair is individually named as primary, secondary and tertiary;
providing for each of said main nodes a coupling capacitor realized as MOSFET in capacitor configuration and fed by associated primary control clock signals out of said set;
providing for auxiliary nodes connecting to each of said auxiliary and said pump signal terminals a coupling capacitor realized as MOSFET in capacitor configuration and fed by associated secondary and tertiary control clock signals out of said set;
providing as twin circuit block stage a general symmetrically cross-over connected Charge Pump (CP)—stage made up of a pair of symmetrically arranged Charge Transfer Switch (CTS) circuit blocks, also named A-part and B-part CTS blocks, whereby these A-part and B-part blocks are identical in structure and assembly of components only differing in their layouts which are mirrored to each other, thus both also designated commonly as CTS parts;
providing as said CTS circuit block an assembly of three MOSFETs, having one input terminal, one output terminal, a pair of auxiliary terminals named first and second, and another pair of pump signal terminals named first and second and all terminals named additionally as CTS part related;
connecting cross-over said pairs of first and second auxiliary terminals of each of said pair of CTS circuit blocks thus making up a symmetrically cross-over connected CP-stage in such a way, that first A-part auxiliary terminal links to second B-part auxiliary terminal and vice-versa;
connecting said pairs of input and output terminals of said general symmetrically cross-over connected CP-stages to said consecutive series of main nodes on each virtual connection line in such a way, that a real serial connection of all of said CP-stages is guaranteed according to their four-pole or two-port character;
one main node on each A- and B-part rail arranged as consecutive pairs connects to said pair of input terminals from one CP-stage respectively and the next main node on each A- and B-part rail connects to said pair of output terminals belonging together to said one CP-stage respectively, in order to now guarantee a serial connection of CP-stages also said pair of input terminals of the following CP-stage is connecting to this same pair of main nodes (to A- and B-part main nodes respectively) and so on for all following stages and main node connections;
and
feeding said two pairs of auxiliary nodes connecting to said pump signal terminals by pairs of secondary and tertiary control clock signals respectively.

11 more elements

Dependencies are inferred from the claim text.

Charge pump circuit for high voltage generation

Life of this patent

Charge pump circuit for high voltage generation

Life of this patent

Abstract

Claims48