Charge pump circuit and method for generating a supply voltage
First Claim
1. A charge pump circuit, comprising:
- a first stage and an at least second stage, each having a capacitor and a current source, wherein the first stage and the at least second stage each comprise;
a first switch arranged between the current source of the respective stage and a first electrode of the capacitor of the respective stage and set in a closed state in a first phase of operation and in an open state in a second phase of operation;
a second switch arranged between the first electrode of the capacitor of the respective stage and an output of the respective stage and set in an open state in the first phase of operation and in a closed state in the second phase of operation; and
a third switch that couples the first electrode of the capacitor of the respective stage to a reference potential terminal and is set in a closed state in a first sub-phase of the first phase of operation and in an open state in a second sub-phase of the first phase of operation and in the second phase of operation; and
a comparator having;
a first input which is coupled to an electrode of one of the capacitors of the first and the at least second stage,a second input for receiving a reference voltage, andan output for generating a comparator signal,wherein the charge pump circuit is configured such that, in the first phase of operation, the capacitor of the first stage is switched in series to the current source of the first stage for charging the capacitor of the first stage and the capacitor of the second stage is switched in series to the current source of the second stage for charging the capacitor of the second stage and that, in the second phase of operation, the capacitor of the first stage and the capacitor of the second stage are switched in series for providing a supply voltage at an output of the charge pump circuit, andwherein the first and the second phase are set depending on the comparator signal.
1 Assignment
0 Petitions
Accused Products
Abstract
A charge pump circuit (11) comprises a first stage (31) and at least a second stage (32), each having a capacitor (130, 230) and a current source (100, 200). The charge pump circuit (11) is configured such that, in a first phase (A) of operation, the capacitor (130) of the first stage (31) is switched in series to the current source (100) of the first stage (31) and the capacitor (230) of the second stage (32) is switched in series to the current source (200) of the second stage (32) and that, in a second phase (B) of operation, the capacitor (130) of the first stage (31) and the capacitor (230) of the second stage (32) are switched in series for providing a supply voltage (VHF) at an output (15) of the charge pump circuit (11). A comparator signal (SCOM) is generated by comparing a voltage at an electrode of one of the capacitors (130, 230) of the first and the at least second stage (31, 32) with a reference voltage (VR). The first and the second phase (A, B) are set depending on the comparator signal (SCOM).
23 Citations
16 Claims
-
1. A charge pump circuit, comprising:
-
a first stage and an at least second stage, each having a capacitor and a current source, wherein the first stage and the at least second stage each comprise; a first switch arranged between the current source of the respective stage and a first electrode of the capacitor of the respective stage and set in a closed state in a first phase of operation and in an open state in a second phase of operation; a second switch arranged between the first electrode of the capacitor of the respective stage and an output of the respective stage and set in an open state in the first phase of operation and in a closed state in the second phase of operation; and a third switch that couples the first electrode of the capacitor of the respective stage to a reference potential terminal and is set in a closed state in a first sub-phase of the first phase of operation and in an open state in a second sub-phase of the first phase of operation and in the second phase of operation; and a comparator having; a first input which is coupled to an electrode of one of the capacitors of the first and the at least second stage, a second input for receiving a reference voltage, and an output for generating a comparator signal, wherein the charge pump circuit is configured such that, in the first phase of operation, the capacitor of the first stage is switched in series to the current source of the first stage for charging the capacitor of the first stage and the capacitor of the second stage is switched in series to the current source of the second stage for charging the capacitor of the second stage and that, in the second phase of operation, the capacitor of the first stage and the capacitor of the second stage are switched in series for providing a supply voltage at an output of the charge pump circuit, and wherein the first and the second phase are set depending on the comparator signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
-
-
10. A method for generating a supply voltage with a charge pump circuit having a first stage and an at least second stage, which each comprises a capacitor and a current source, the method comprising:
-
in a first phase of operation, switching the capacitor of the first stage in series to the current source of the first stage for charging the capacitor of the first stage and switching the capacitor of the second stage in series to the current source of the second stage for charging the capacitor of the second stage; in a second phase of operation, providing a supply voltage at an output by switching the capacitor of the first stage and the capacitor of the second stage in series; generating a comparator signal by comparing a voltage at an electrode of one of the capacitors of the first and the at least second stage with a reference voltage; and setting the first and the second phase on the basis of the comparator signal, wherein the current sources are controlled such that the currents provided by the current sources rise with rising temperature. - View Dependent Claims (11, 12, 13, 14, 15)
-
-
16. A charge pump circuit, comprising:
-
a first stage and an at least second stage, each having a capacitor and a current source; a comparator having; a first input which is coupled to an electrode of one of the capacitors of the first and the at least second stage, a second input for receiving a reference voltage, and an output for generating a comparator signal; and a reference voltage circuit for generating the reference voltage based on a bandgap voltage and a signal from a ramp rate control oscillator, wherein the charge pump circuit is configured such that, in a first phase of operation, the capacitor of the first stage is switched in series to the current source of the first stage for charging the capacitor of the first stage and the capacitor of the second stage is switched in series to the current source of the second stage for charging the capacitor of the second stage and that, in a second phase of operation, the capacitor of the first stage and the capacitor of the second stage are switched in series for providing a supply voltage at an output of the charge pump circuit, and wherein the first and the second phase are set depending on the comparator signal and control signals for the first and the second phase are derived from the comparator signal only without further using the signal from the ramp rate control oscillator.
-
Specification