Transmitter digital-to-analog converter (dac)- baseband filter (bbf) common mode interface
AssigneeQUALCOMM Incorporated
InventorsMinghui Chen, Mahim Ranjan, Jeremy Mark Goldblatt, Frederic Bossu
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Abstract
Removing common-mode current from a pair of complementary current signals, including: generating a common-mode voltage of the pair of complementary current signals including at least a first current signal and a second current signal; measuring and outputting a difference voltage between the generated common-mode voltage and a common-mode reference voltage; and removing at least a portion of the common-mode current from the first current signal and the second current signal based on the difference voltage.
Claims20
A circuit for removing common-mode current from a pair of complementary current signals, the circuit comprising:
- a generator unit configured to generate a common-mode voltage of the pair of complementary current signals comprising at least a first current signal and a second current signal;
- and
- a measurement unit configured to measure and output a difference voltage configured to remove the common-mode current from the first current signal and the second current signal, wherein the difference voltage is based on a difference between the common-mode voltage generated by the generator unit and a common-mode reference voltage.
A method for removing common-mode current from a pair of complementary current signals, the method comprising:
- generating a common-mode voltage of the pair of complementary current signals comprising at least a first current signal and a second current signal;
- measuring and outputting a difference voltage between the generated common-mode voltage and a common-mode reference voltage;
- and
- removing at least a portion of the common-mode current from the first current signal and the second current signal based on the difference voltage.
An apparatus for removing common-mode current from a pair of complementary current signals, the apparatus comprising:
- means for generating a common-mode voltage of the pair of complementary current signals comprising at least a first current signal and a second current signal;
- means for measuring and outputting a difference voltage between the generated common-mode voltage and a common-mode reference voltage;
- and
- means for removing the common-mode current from the first current signal and the second current signal based on the difference voltage.
A circuit for removing common-mode current from a pair of complementary current signals received from a digital-to-analog converter (DAC) and sent to a baseband filter (BBF) of a transmitter, the circuit comprising:
- a first node to receive a first current signal of the pair of complementary current signals from the DAC, the first node coupled to a positive terminal of an operational amplifier in the BBF;
- a second node to receive a second current signal of the pair of complementary current signals from the DAC, the second node coupled to a negative terminal of the operational amplifier in the BBF;
- a first resistor coupled to the first node to remove the common-mode current from the first current signal;
- and
- a second resistor coupled to the second node to remove the common-mode current from the second current signal.
Dependencies are inferred from the claim text.