详细描述
The RF2056 is a low power, high performance, VHF/UHF frequency conversion chip with integrated local oscillator (LO) generation and a pair of mixers. The synthesizer includes an integrated fractional-N phase locked loop that can control the VCO to produce a low phase noise and low spurious LO signal with very fine frequency resolution. The VCO output can then be divided by one, two, or four in the LO divider, the output of which drives the mixer, which converts the signal into the required frequency band. The mixer bias current can be programmed dependent on the required performance and available supply current. The LO generation block has been designed to operate with the VCO covering the frequency range from 200 MHz to 500 MHz, dependant on the value of the external inductor used. With the LO dividers, the LO range achievable is within the range of 50 MHz to 500 MHz. The mixer is broadband and can operate from 30 MHz to 500 MHz at the input and output, enabling both up and down conversion. An external crystal of between 10 MHz and 26 MHz, or an external reference source of between 10 MHz and 104 MHz, can be used with the RF2056 to accommodate a variety of reference frequency options.
All on-chip registers are controlled through a simple three-wire serial interface. The RF2056 is designed for 2.7 V to 3.6 V operation. It is available in a plastic 32-pin, 5 mm x 5 mm QFN package.
特点
Fractional-N Synthesizer
Very Fine Frequency Resolution 1.5 Hz for 26 MHz Reference
LO Frequency Range Between 50 MHz and 500 MHz
Low Phase Noise VCO
VCO Range 200 MHz to 500 MHz
Dependent on External Inductor
Integrated LO Buffers and LO Dividers
On-Chip Crystal-Sustaining?Circuit With Programmable?Loading Capacitors
Two High-Linearity RF Mixers
Mixer Frequency Range 30 MHz to 500 MHz
Mixer Input IP3 +25 dBm
Mixer Bias Adjustable for Low Power Operation
2.7 V to 3.6 V Power Supply
Low Current Consumption 45 mA to 65 mA at 3 V
3-Wire Serial Interface