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US 2002/0075705 A1Published application
Dc/dc converter and method of operating a dc/dc converter
AssigneeTexas Instruments Incorporated
InventorsErich Bayer, Hans Schmeller
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AssigneeTexas Instruments Incorporated
InventorsErich Bayer, Hans Schmeller
Estimating the term…
The invention relates to a DC/DC converter including a charge pump circuit comprising one or more capacitors and a plurality of controllable switches connected thereto, the controllable switches being controllable by a control circuit so that the capacitor(s) is/are alternatingly switched in a charging and discharge phase; a first current source set to a predetermined base current located either in the discharge or charging path of the charge pump circuit and a second current source connected in parallel thereto; and a regulator circuit for generating a first control signal representing the difference between a voltage characterizing the output voltage and a first reference voltage and controlling the second current source when the charge pump circuit is active so that the controllable current is reduced or increased with an increase and reduction respectively in the difference to track the voltage characterizing the output voltage in accordance with the first reference voltage; and for generating a second control signal guided to the control circuit, this signal assuming a first status when the voltage characterizing the output voltage exceeds a second reference voltage at a predetermined level above the first reference voltage, upon which the control circuit deactivates the charge pump circuit, and assumes a second status when the voltage characterizing the output voltage drops below the second reference voltage, upon which the control circuit activates the charge pump circuit. The invention relates further to a method of operating a DC/DC converter.
A DC/DC converter
The DC/DC converter as set forth in any of the preceding claims comprising in addition a reference voltage generator circuit for generating said first reference voltage.
The DC/DC converter as set forth in any of the preceding claims wherein said control circuit comprises a clock, the clock signal of which cycles said controllable switches of said charge pump circuit ON/OFF.
The DC/DC converter as set forth in any of the preceding claims wherein one or more of said controllable switches forms said first current source and/or said controllable second current source.
The DC/DC converter as set forth in any of the preceding claims wherein all of said controllable switches are MOSFETs.
The DC/DC converter as set forth in any of the preceding claims wherein said charge pump circuit comprises a charge pump capacitor and four controllable switches, one electrode of said charge pump capacitor being connectable via a first of said four switches to the input voltage of said converter and via a second of said four switches to GND, and the other electrode of said capacitor being connectable via the third of said four switches to said input voltage and via the fourth of said four switches to the output of said converter.
The DC/DC converter as set forth in any of the preceding claims comprising a further charge pump circuit configured and circuited corresponding to said first charge pump circuit, the controllable switches of said further charge pump circuit being signalled by said control signal opposite in phase to those of said first charge pump circuit so that the ripple of said output voltage of said DC/DC converter is reduced.
A method for operating a DC/DC converter including a charge pump circuit comprising one or more charge pump capacitors and a plurality of controllable switches connected thereto comprising the steps
Dependencies are inferred from the claim text.