Skyworks announces frequency synthesizer for land mobile radio (LMR)
The SKY72310-11 is a 50MHz to 2.1GHz fractional-N frequency synthesizer for high-performance land mobile radio/professional mobile radio (LMR/PMR) systems, from Skyworks.
According to Skyworks, it simplifies transmitter design and is ideal for rugged portable and mobile two-way radios used in business as well as and mission-critical applications.
The synthesizer is for use in a phase locked loop (PLL), providing frequency resolution and low phase-noise performance. It has a low power consumption of 4mA at 3V, 900MHz to extend battery life. The configurable delta sigma architecture and a 10 or 18-bit modulator enable system designers to determine step size, phase noise, and reference spurious performance, explains Skyworks.
The SKY72310-11 has a fine step size of less than 100Hz, allowing the 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 ovenised crystal oscillators, reducing parts count and associated component cost. The device’s fine step size can also be used for Doppler shift corrections.
Reference crystals or oscillators up to 50 MHz can be used with the synthesizer. The crystal frequency is divided down by independent programmable dividers (one to 32). The phase detector can operate at a maximum speed of 50MHz, which allows better phase noise due to the lower division value, notes the company. 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. Typical switching times of less than 100 micro seconds can be achieved. The lower in-band phase noise also permits the use of lower cost voltage controlled oscillators (VCOs) in customer applications.
The SKY72310-11 is available in a 24-pin MCM (4.0 x 4.0mm), to MSL3 and operating at 260 degrees C per JEDEC J-STD-020.
