Chip maker unveils lowest-noise LMX2541 frequency synthesizer.

National Semiconductor Corp on Monday introduced its Powerwise LMX2541 chip, equipped with integrated VCO, the industry's fully integrated lowest –noise frequency synthesizer.

The new chip features ultra-low-noise delta-sigma fractional-N PLL, voltage-controlled oscillator (VCO), divider and output drive and offers advanced features such as programmable output power, digital frequency-shift-keying (FSK) modulation, a FastLock mode with cycle-slip reduction and a low-noise, integrated-input crystal oscillator circuit.

The chip provides less than 2 milli-radians (mrad) root-mean-square (rms) noise at 2.1 GHz and 3.5 mrad rms noise at 3.5 GHz, and well-suited for local oscillator (LO) applications in next-generation base station radio transceivers such as Long-Term Evolution (LTE), Worldwide Interoperability for Microwave Access (WiMAX), and multi-standard radios.

It also integrates low-dropout (LDO) regulators and output-driver matching network to provide higher supply noise immunity and more consistent performance, and it has a supply voltage range of 3.15V to 3.45V and device programming is facilitated using a three-wire MICROWIRE(R) bus interface that can operate down to 1.8V.

The LMX2541 is now available on in a 6 mm by 6 mm, 36-pin LLP package at $9.50 each in 1,000-unit quantities. For more information please visit http://www.national.com/pf/LM/LMX2541.html