US Patent No. 9,742,415

APPARATUS FOR LINEARIZING A DIFFERENTIAL CHARGE PUMP


Patent No. 9,742,415
Issue Date August 22, 2017
Title Apparatus For Linearizing A Differential Charge Pump
Inventorship Shirin Chegeni, Sunnyvale, CA (US)
Koushik Krishnan, San Jose, CA (US)
Assignee Quantenna Communications, Inc., Fremont, CA (US)

Claim of US Patent No. 9,742,415

2. A charge pump comprising:
a differential charge pump having differential inputs and primary and mirror outputs, and the differential charge pump responsive
to a down signal at the differential inputs to provide a negative current at the primary output and a positive current at
the mirror output, and responsive to an up signal at the differential inputs to provide a positive current at the primary
output and a negative current at the mirror output;

an auxiliary charge pump having differential inputs and an auxiliary output coupled to the mirror output of the differential
charge pump, and responsive to the down signal at the differential inputs to provide a negative current at the auxiliary output,
and responsive to the up signal at the differential inputs to provide a positive current at the auxiliary output; and the
auxiliary charge pump including:

a positive voltage source;
a first resistor coupled to the positive voltage source;
a 1st switch switchably coupling and uncoupling the first resistor to the auxiliary output responsive to the up signal and the down
signal respectively;

a negative voltage source;
a second resistor coupled to the negative voltage source;
a 2nd switch switchably coupling and uncoupling the second resistor to the auxiliary output responsive to the down signal and the
up signal respectively.