Apparatus and method for frequency calibration in frequency synthesizer

• Main Authors: LIM KYOOHYUN, KANG KISUB, OH SECHANG
• Format: Patent
• Language: English
• Published: 27.08.2013
• Subjects: AUTOMATIC CONTROL, STARTING, SYNCHRONISATION, OR STABILISATIONOF GENERATORS OF ELECTRONIC OSCILLATIONS OR PULSES; BASIC ELECTRONIC CIRCUITRY; ELECTRICITY

An apparatus and a method for frequency calibration in a frequency synthesizer are disclosed. The present invention includes an up/down processor. The up/down processor is utilized for outputting one of a GND voltage and a VDD voltage to a voltage-controlled oscillator via a loop filter in an open loop status, or outputting one of a step-up voltage and a step-down voltage in accordance with a phase difference to the voltage-controlled oscillator via the loop filter in a close loop status. When the up/down processor outputs one of the GND voltage and the VDD voltage in the open loop status, a memory bank selector compares frequencies for selecting a value of a memory bank and then adds an offset to the value of the memory bank so as to determine a final value of a VCO memory bank in the phase locked loop.