High voltage charge-pump with a feedback control loop
A high voltage charge-pump includes a plurality of voltage boosting stages, a low voltage input, and at least one clock input. A sensing charge-pump having a voltage detector output has at least one voltage sensing stage that is communicably coupled to at least one of the plurality of voltage boosting stages. A loop filter in a feedback control loop includes a voltage detector input coupled to the voltage detector output, a voltage reference input, and a voltage error output. A voltage controlled oscillator (VCO) with a variable frequency output has a voltage error input coupled to the voltage error output. The feedback control loop also includes at least one driver having a variable frequency input coupled to the variable frequency output and at least one clock output coupled to the at least one clock input.
1. A charge-pump circuit comprising:
a charge-pump section having a low voltage input, at least one clock input and a high voltage output, the charge-pump section including a plurality of voltage boosting stages;
a sensing charge-pump having a voltage detector output, the sensing charge-pump including a voltage sensing stage, the voltage sensing stage communicably coupled to at least one of the plurality of voltage boosting stages and adapted to selectively charge and discharge at least one capacitor from a voltage present at the coupled at least one of the plurality of voltage boosting stages to produce a sensing voltage; and
a voltage controlled oscillator (VCO) in communication with the voltage detector output and the at least one clock input and adapted to vary the frequency of a clock signal delivered to the at least one clock input based upon the voltage detector output.
2. The charge-pump circuit of claim 1 , wherein the charge-pump section has a Dickson type charge-pump topology.
3. The charge-pump circuit of claim 1 , wherein the voltage sensing stage comprises a diode having an anode coupled to one of the plurality of voltage boosting stages and a cathode coupled to the at least one capacitor having a first end that is usable as the voltage detector output and a second end that is coupled to a fixed voltage node.
4. The charge-pump circuit of claim 3 , wherein the fixed voltage node is a ground node.
5. The charge-pump circuit of claim 1 , wherein the charge-pump circuit is adapted to receive an enable signal for activating and deactivating the charge-pump circuit.
6. A charge-pump circuit comprising:
a charge-pump section having a low voltage input, at least one clock input and a high voltage output, the charge-pump section including a plurality of voltage boosting stages; and
a sensing charge-pump having a voltage detector output, the sensing charge-pump including at least one voltage sensing stage communicably coupled to at least one of the plurality of voltage boosting stages;
a loop filter having a voltage detector input coupled to the voltage detector output, a voltage reference input, and a voltage error output;
a voltage controlled oscillator (VCO) having a voltage error input coupled to the voltage error output and a variable frequency output; and
at least one driver having a variable frequency input coupled to the variable frequency output and at least one clock output coupled to the at least one clock input of the charge-pump section.
7. The charge-pump circuit of claim 6 , wherein a band gap voltage reference is coupled to the voltage reference input of the loop filter.
8. The charge-pump circuit of claim 6 , wherein the loop filter is an integrator type loop filter.
9. A mobile terminal comprising:
an antenna;
a micro-electro-mechanical systems (MEMS) switch coupled to the antenna;
a charge-pump circuit having a high voltage output for activating the MEMS switch, the charge pump circuit comprising:
a charge-pump section having a low voltage input, at least one clock input and the high voltage output, and a plurality of voltage boosting stages; and
a sensing charge-pump having a voltage sensing output, the sensing charge-pump including at least one voltage sensing stage communicably coupled to at least one of the plurality of voltage boosting stages, and
a control system for enabling and disabling the charge pump circuit.
10. The mobile terminal of claim 9 , wherein the charge-pump circuit further includes:
a loop filter having a voltage detector input coupled to the voltage sensing output, a voltage reference input, and a voltage error output;
a voltage controlled oscillator (VCO) having a voltage error input coupled to the voltage error output and a variable frequency output; and
at least one driver having a variable frequency input coupled to the variable frequency output and at least one clock output coupled to the at least one clock input of the charge-pump section.
11. The mobile terminal of claim 10 , wherein a band gap voltage reference is coupled to the voltage reference input of the loop filter.
12. The mobile terminal of claim 10 , wherein the loop filter is an integrator type loop filter.
13. The mobile terminal of claim 9 , wherein the charge-pump section has a Dickson type charge-pump topology.
14. The mobile terminal of claim 9 , wherein the at least one voltage sensing stage comprises a diode having an anode coupled to one of the plurality of voltage boosting stages and a cathode coupled to a holding capacitor having a first end that is usable as the voltage sensing output and a second end that is coupled to a fixed voltage node.
15. The mobile terminal of claim 14 , wherein the fixed voltage node is a ground node.
16. A charge-pump circuit comprising:
a charge-pump section having a low voltage input, at least one clock input and a high voltage output, the charge-pump section including a plurality of voltage boosting stages;
a sensing charge-pump having a voltage detector output, the sensing charge-pump including at least one voltage sensing stage communicably coupled to at least one of the plurality of voltage boosting stages; and
a feedback loop comprising:
a loop filter having a voltage detector input coupled to the voltage detector output, a voltage reference input, and a voltage error output;
a voltage controlled oscillator (VCO) having a voltage error input coupled to the voltage error output and a variable frequency output; and
at least one driver having a variable frequency input coupled to the variable frequency output and at least one clock output coupled to the at least one clock input of the charge-pump section.
17. The charge-pump circuit of claim 16 , wherein a band gap voltage reference is coupled to the voltage reference input of the loop filter.
18. The charge-pump circuit of claim 16 , wherein the loop filter is an integrator type loop filter.
19. The charge-pump circuit of claim 16 , wherein the charge-pump section is a Dickson charge-pump.
20. The charge-pump circuit of claim 16 , wherein the charge-pump circuit is adapted to be activated and deactivated by an enable signal.