Patent application number | Description | Published |
20090121759 | FAST-SWITCHING LOW-NOISE CHARGE PUMP - In one embodiment of the invention, a method for a charge pump is disclosed. The method includes biasing a plurality of transistors; switching a pair of main transistor switches to apply or remove a net charge on an output terminal though the biased transistors; and turning on auxiliary transistor switches when the main transistor switches are turned off. The auxiliary transistor switches when turned on provide an auxiliary equalizing path to nodes between the main transistor switches and the biased transistors. The auxiliary equalizing path equalizes voltages between the intermediate nodes to rapidly turn off the biased transistors and reduce noise on the output terminal of the charge pump. | 05-14-2009 |
20090261917 | AUXILIARY VARACTOR FOR TEMPERATURE COMPENSATION - Techniques for compensating for the effects of temperature change on voltage controlled oscillator (VCO) frequency are disclosed. In an embodiment, an auxiliary varactor is coupled to an LC tank of the VCO. The auxiliary varactor has a capacitance controlled by a temperature-dependant control voltage to minimize the overall change in VCO frequency with temperature. Techniques for generating the control voltage using digital and analog means are further disclosed. | 10-22-2009 |
20090278620 | VCO CAPACITOR BANK TRIMMING AND CALIBRATION - Techniques are disclosed for trimming a capacitance associated with a capacitor bank for use in a voltage-controlled oscillator (VCO). In an embodiment, each capacitance is sub-divided into a plurality of constituent capacitances. The constituent capacitances may be selectively enabled or disabled to trim the step sizes of the capacitor bank. Further techniques are disclosed for calibrating the trimmable capacitance to minimize step size error for the capacitor bank. | 11-12-2009 |
20100225402 | VCO TUNING WITH TEMPERATURE COMPENSATION - Techniques for setting a fine tuning input signal Vtune for a voltage-controlled oscillator (VCO) in a coarse tuning mode of the VCO. In an exemplary embodiment, the fine tuning input signal during coarse tuning mode is made temperature-dependent to account for possible variation of Vtune over temperature during fine tuning mode. Methods and apparatuses employing the techniques are further described. | 09-09-2010 |
20100295622 | SYSTEMS AND METHODS FOR SELF TESTING A VOLTAGE CONTROLLED OSCILLATOR IN AN OPEN LOOP CONFIGURATION - Methods and apparatus for self testing a multiband voltage controlled oscillator (VCO) are disclosed. A tuning voltage of the VCO is adjusted where the output of the VCO does not affect the input to the VCO. Frequency bands in the VCO are selected. Output frequencies of the VCO are measured. | 11-25-2010 |
20110291716 | FAST-SWITCHING LOW-NOISE CHARGE PUMP - In one embodiment of the invention, a method for a charge pump is disclosed. The method includes biasing a plurality of transistors; switching a pair of main transistor switches to apply or remove a net charge on an output terminal though the biased transistors; and turning on auxiliary transistor switches when the main transistor switches are turned off. The auxiliary transistor switches when turned on provide an auxiliary equalizing path to nodes between the main transistor switches and the biased transistors. The auxiliary equalizing path equalizes voltages between the intermediate nodes to rapidly turn off the biased transistors and reduce noise on the output terminal of the charge pump. | 12-01-2011 |
20120187994 | SYSTEM FOR I-Q PHASE MISMATCH DETECTION AND CORRECTION - System for I-Q phase mismatch detection and correction. An apparatus to correct a phase mismatch between I and Q signals includes a correction circuit configured to continuously compare a reference signal and a phase error signal associated with the I and Q signals to generate an I bias signal and a Q bias signal, a first CMOS buffer configured to receive the I signal and the I bias signal and output a phase adjusted I signal based on the I bias signal, and a second CMOS buffer configured to receive the Q signal and the Q bias signal and output a phase adjusted Q signal based on the Q bias signal. | 07-26-2012 |
20140253255 | VOLTAGE CONTROLLED OSCILLATOR BAND-SELECT FAST SEARCHING USING PREDICTIVE SEARCHING - A method, an apparatus, and a computer program product are provided. The apparatus tunes a frequency provided by a VCO. The apparatus determines a relative capacitance change associated with a first frequency and a desired frequency from a look-up table. The apparatus adjusts a capacitor circuit in the VCO based on the determined relative capacitance change determined from the look-up table in order to tune from the first frequency to the desired frequency. The apparatus determines that the frequency provided by the VCO is a second frequency different than the desired frequency after adjusting the capacitor circuit. The apparatus performs an iterative search to further adjust the capacitor circuit when a difference between the second frequency and the desired frequency is greater than a threshold. | 09-11-2014 |