SKY72301-22数据手册集成电路（IC）的时钟发生器PLL频率合成器规格书PDF

描述 Description

Skyworks SKY72301-22 direct digital modulation fractional-N frequency synthesizer provides ultra-fine frequency resolution, fast switching speed, and low phase-noise performance. This synthesizer is a key building block for high-performance radio system designs that require low power and fine step size.
The ultra-fine step size of less than 100 Hz allows this synthesizer to be used in very narrowband wireless applications. With proper temperature sensing or through control channels, the synthesizer’s fine step size can compensate for crystal oscillator or Intermediate Frequency (IF) filter drift. As a result, crystal oscillators or crystals can replace temperature- compensated or ovenized crystal oscillators, reducing parts count and associated component cost. The device’s fine step size can also be used for Doppler shift corrections.
The SKY72301-22 has a phase noise floor of –95 dBc/Hz up to 1.0 GHz operation as measured inside the loop bandwidth. This is permitted by the on-chip low noise dividers and low divide ratios provided by the device’s high fractionality.
Reference crystals or oscillators up to 50 MHz can be used with the SKY72301-22. The crystal frequency is divided down by independent programmable divider ratios of 1 to 32 for the main and auxiliary synthesizers. The phase detectors can operate at a maximum speed of 25 MHz, which allows better phase noise due to the lower division value. With a high reference frequency, the loop bandwidths can also be increased. Larger loop bandwidths improve the settling times and reduce in-band phase noise. Therefore, typical switching times of less than 100 s can be achieved. The lower in-band phase noise also permits the use of lower cost Voltage Controlled Oscillators (VCOs) in customer applications.
The SKY72301-22 has a frequency power steering circuit that helps the loop filter steer the VCO when the frequency is too fast or too slow, further enhancing acquisition time.
The unit operates with a three-wire, high-speed serial interface. A combination of a large bandwidth, fine resolution, and the three-wire, high-speed serial interface allows for a direct frequency modulation of the VCO. This supports any continuous phase, constant envelope modulation scheme such as Frequency Modulation (FM), Frequency Shift Keying (FSK), Minimum Shift Keying (MSK), or Gaussian Minimum Shift Keying (GMSK).
The capability to support such modulation schemes eliminates the need for In-Phase and Quadrature (I/Q) Digital-To-Analog Converters (DACs), quadrature upconverters, and IF filters from the transmitter portion of the radio system.

特性 Features

·Spur-free operation
·1 GHz maximum operating frequency
·500 MHz maximum auxiliary synthesizer
·Ultra-small step size, 100 Hz or less
·High internal reference frequency enables large loop bandwidth implementations
·Very fast switching speed (e.g., below 100 µs)
·Phase noise to –96 dBc/Hz inside the loop filter bandwidth @ 950 MHz
·Software programmable power-down modes
·High-speed serial interface up to 100 Mbps
·Three-wire programming
·Programmable division ratios on reference frequency
·Phase detectors with programmable gain provide a programmable loop bandwidth
·Frequency power steering further enhances rapid acquisition time
·On-chip crystal oscillator
·Frequency adjust for temperature compensation
·Direct digital modulation
·3 V operation

简介

SKY72301-22属于集成电路（IC）的时钟发生器PLL频率合成器。由制造生产的SKY72301-22时钟发生器，PLL，频率合成器时钟发生器、PLL 和频率合成器集成电路 (IC) 可为逻辑器件提供参考信号的稳定定时脉冲，这些器件包括计算机、微控制器、数据通信系统和图形/视频发生器。这些集成电路可能包括缓冲器、驱动器、分频器、倍频器、多路复用器、合成器、扇出分配器和预分频器。