RFMD2081

The RFMD2081 is a low power, wideband, IQ modulator with integrated fractional-N synthesizer and voltage controlled oscillator (VCO). The modulator features an input 3dB bandwidth of 100MHz, and 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 local oscillator (LO) signals from 90MHz to 5400MHz. The LO 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. This device also features a differential input for an external VCO or LO source. 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 135mA from a 3V supply.

Features:

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

-40dBc Unadjusted Carrier Suppression

-40dBc Unadjusted Sideband Suppression

100MHz Baseband Input 3dB Bandwidth

Very Low Noise Floor -162dBm/Hz Typical

Output P1dB +4dBm

Output IP3 +17dBm

2.7V to 3.3V Power Supply

135mA Typical Current Consumption

Serial Programming Interface