National frequency synthesizers suit 2.5G, 3G basestations

vNational Semiconductor Corp. has expanded its PLLatinum line of PLL products with the addition of the LMX2346 and LMX2347 frequency synthesizers that feature low-phase noise and are targeted for 2G, 2.5G, and 3G basestations.

Manufactured using the company's advanced BiCMOS process, both devices exhibit a phase noise of -91dBc/Hz (900MHz) and -85dBc/Hz (1.96MHz), enabling improved radio sensitivity, which results to fewer dropped calls, extended basestation range, and improved voice quality.

They also employ a proprietary digital PLL technique to generate stable, low noise control signals for UHF and VHF VCOs. Other features include a charge pump power supply voltage of up to 6V, a selectable oscillator input buffer mode that minimizes buffer noise current, and the support of higher reference frequencies of up to 104MHz.

The LMX2346 and LMX2347 operate at frequencies up to 2GHz and 2.5GHz, respectively, and offer 2.7V to 5.5V operation, current consumption of 6.5mA, and digital lock detect.

Available in both CSP-16 and TSSOP-16 packages, the LMX2346 and LMX2347 are priced starting at $2.05 and $2.50, respectively, in 1,000-unit quantities.