Filter networks for driving capacitive loads
AssigneeMediaTek Singapore Pte. Ltd.
InventorsBryan Liangchin Huang, Osama Khalil Shanaa
Life of this patent
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Abstract
According to at least one aspect, a filter network is provided. The filter network comprises: an active filter comprising an amplifier (e.g., an operational amplifier), wherein the active filter is configured to add at least one member selected from the group consisting of a pole and a zero to a transfer function of the filter network; a passive filter coupled to the active filter and configured to add at least one pole to the transfer function of the filter network; and a non-inverting amplifier (e.g., a voltage buffer) having an input coupled to the passive filter and an output coupled to the active filter.
Claims20
A filter network, comprising:
- an active filter comprising an amplifier, wherein the active filter is configured to add at least one member selected from the group consisting of a pole and a zero to a transfer function of the filter network, the amplifier comprising a first input, a second input, a first output and a second output;
- a passive filter coupled to the active filter and configured to add at least one pole to the transfer function of the filter network, the passive filter comprising at least one first passive component coupled to the first output of the amplifier and at least one second passive component coupled to the second output of the amplifier;
- and
- a non-inverting amplifier having a first input coupled to the at least one first passive component, a second input coupled to the at least one second passive component, a first output coupled to the first input of the amplifier and a second output coupled to the second input of the amplifier,
- wherein the non-inverting amplifier does not include an operational amplifier, and
- wherein the amplifier has an open-loop gain that is at least 10 times larger than an open-loop gain of the non-inverting amplifier.
A filter network, comprising:
- an amplifier having a first input, a second input, a first output and a second output;
- a passive filter coupled to the first and second outputs of the amplifier and configured to add at least one pole to a transfer function of the filter network;
- a voltage buffer having first and second inputs coupled to first and second outputs of the passive filter, respectively, and first and second outputs coupled to the first and second inputs of the amplifier, respectively;
- and
- a circuit package housing at least the amplifier, the passive filter, and the voltage buffer,
- wherein the voltage buffer does not include an operational amplifier, and
- wherein the amplifier has an open-loop gain that is at least 10 times larger than the open-loop gain of the voltage buffer.
A filter network, comprising:
- an amplifier having a first input, a second input, a first output and a second output;
- a passive filter coupled to the first and second outputs of the amplifier and configured to add at least one pole to a transfer function of the filter network;
- and
- a voltage buffer means having first and second inputs coupled to the passive filter and first and second outputs coupled to the first and second inputs of the amplifier, respectively,
- wherein the voltage buffer means does not include an operational amplifier, and
- wherein the amplifier has an open-loop gain that is at least 10 times larger than an open-loop gain of the voltage buffer means.
Dependencies are inferred from the claim text.