The ADL5380 is a broadband quadrature I-Q demodulator that covers an RF/IF input frequency range from 400 MHz to 6 GHz. With a NF = 10.9 dB, IP1dB = 11.6 dBm, and IIP3 = 29.7 dBm @ 900 MHz, the ADL5380 demodulator offers outstanding dynamic range suitable for the demanding infrastructure direct-conversion requirements. The differential RF inputs provide a well-behaved broadband input impedance of 50 Ω and are best driven from a 1:1 balun for optimum performance.
Excellent demodulation accuracy is achieved with amplitude and phase balances of ~0.07 dB and ~0.2°, respectively. The demodulated in-phase (I) and quadrature (Q) differential outputs are fully buffered and provide a voltage conversion gain of ~7 dB. The buffered baseband outputs are capable of driving a 2 V p-p differential signal into 200 Ω.
The fully balanced design minimizes effects from second-order distortion. The leakage from the LO port to the RF port is <−50 dBm. Differential dc offsets at the I and Q outputs are typically <20 mV. Both of these factors contribute to the excellent IIP2 specification, which is >65 dBm.
The ADL5380 operates off a single 4.75 V to 5.25 V supply. The supply current is adjustable by placing an external resistor from the ADJ pin to either the positive supply, VS, (to increase supply current and improve IIP3) or to ground (which decreases supply current at the expense of IIP3).
The ADL5380 is fabricated using the Analog Devices, Inc., advanced silicon-germanium bipolar process and is available in a 24-lead exposed paddle LFCSP.
