Broadband gain and power control

Analog Devices has introduced what it claims is the industry’s first single-chip RF VGA (variable-gain amplifier/attenuator) that operates at RF power levels for wireless infrastructure equipment.

The ADL5330 is also the first monolithic VGA to provide broadband operation from 1 MHz to 3 GHz with a precision 60-dB linear-in-dB gain-control range. The company says that these features, critical to demanding radio designs, have never before been available within a single integrated circuit (IC).

Unlike conventional discrete solutions that require many external components, the single-chip ADL5330 integrates broadband amplifiers and attenuators, offering savings in board area, component count and solution cost as compared to discrete implementations. The precision linear-in-dB control interface further simplifies and eases circuit design.

The ADL5330 provides 60 dB dynamic gain and attenuation (approximately +20 dB gain and -40 dB attenuation), an output power level of 22 dBm (1-dB compression point), an output third-order intercept (OIP3) of + 31 dBm at 1 GHz and a noise figure (NF) of 8 dB.

The dynamic range of the ADL5330, combined with its low distortion and low noise, makes the device an ideal choice for transmit signal paths – at both RF and IF frequencies – within wireless infrastructure equipment such as cellular base stations (CDMA, W-CDMA, GSM), point-to-point and point-to-multipoint radio links, satellite equipment, wireless local loop and broadband access services.

The ADL5330 can be used with the company’s I/Q modulators (AD8345, AD8346 and AD8349) and power detectors (AD8313, AD8314 and AD8362) to enable a complete transmit signal path.

Currently sampling in 24-lead (4 mm × 4 mm) chip-scale packaging (CSP), the device is priced at $4.98 per unit in 1,000-piece quantities. Full production will begin in February 2005.

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