详细描述
The RFMD2080 is a low power, highly integrated, IQ modulator with integrated fractional-N synthesizer and voltage controlled oscillator (VCO). The RFMD2080 can generate output frequencies of between 45MHz and 2700MHz, making it suitable for a wide range of applications.
The fractional-N synthesizer takes advantage of an advanced sigma-delta architecture that delivers ultra-fine step sizes and low spurious products. The synthesizer/VCO combined with an external loop filter allows the user to generate an oscillator signal covering 90MHz to 5400MHz. The signal is buffered and routed to a high accuracy quadrature divider (/2) that drives the balanced I and Q mixers. The output of the mixers are summed and applied to a differential RF output stage. The device also features a differential input for an external VCO or LO source.
The baseband I and Q stages are highly integrated; featuring variable gain and filtering as well as generation of DC offset voltages. The programmable DC offsets enable improved carrier suppression. The baseband input 3dB bandwidth can be tuned from 1.5MHz to 10MHz, and the total gain control range is 38dB with 2dB resolution.
Device programming is achieved via a simple 3-wire serial interface. In addition, a unique programming mode allows up to four devices to be controlled from a common serial bus. This eliminates the need for separate chip-select control lines between each device and the host controller. Up to six general purpose outputs are provided, which can be used to access internal signals (the LOCK signal, for example) or to control front end components. The device is optimized for low power operation, consuming typically only 155mA from a 3V supply.
特点
RF Output Frequency Range 45MHz to 2700MHz
Fractional-N Synthesizer with Very Low Spurious Levels
Typical Step Size 1.5Hz
Fully Integrated Wideband VCOs and LO Buffers
Integrated Phase Noise <0.2° rms at 1GHz
Integrated Baseband Amplification Stage with Variable Gain and Filtering
Tunable Baseband Filters Input 3dB Bandwidth from 1.5MHz to 10MHz
-45dBc Unadjusted Carrier Suppression
-40dBc Unadjusted Sideband Suppression
Very Low Noise Floor -150dBm/Hz Typical
Output P1dB +4dBm
Output IP3 +18dBm
3.0V to 3.3V Power Supply
155mA Typical Current Consumption
Serial Programming Interface