LOW NOISE AMPLIFIERS

 XC240x SERIES

Low Noise, High Gain Solutions using a CMOS Process

Torex use an advanced CMOS manufacturing process to produce high-gain, Low Noise Amplifiers (LNA), which offer both low noise operation (NF) and ultra low power consumption. Our new XC2401A8167R-G and XC2404A816UR-G are the first generation of Torex low cost 'CMOS' LNA.

Both chips are designed to operate at 1.575GHz and target GPS, Galileo, and GLONASS applications.

Simplified Block Diagrams:

Low Noise and High Gain...

The XC2401A8167R-G is a single stage LNA and achieves a 15dB gain with an ultra-low-noise figure of 0.69dB @ 1.575GHz while providing a IP1dB of -12dBm and an IIP3 of -1dBm.

Fig 1. XC2401A8167R-G; Typical Performance Characteristics (Gain & Noise Figure vs. Frequency)

The XC2404A816UR-G includes a 2nd LNA stage to increase the gain to 26.5dB with only a minimal reduction in Noise performance, typically 0.94dB @ 1.575GHz.

However the Noise Figure can be further reduced with careful selection of external components and an NF as low as 0.75dB is possible using only five (5) external components.

Fig2. XC2404A816UR-G Noise Figure vs. Frequency with special external component selection

Low Cost CMOS Process

Using CMOS process has allowed Torex to lower power consumption, but CMOS also has much lower costs when compared with more traditional SiGe and GaAs fabrication methods so this gives the double benefits; lower power and lower price.

Torex utilised a 0.13µ CMOS process to minimise cost and reduce current consumption. The XC2401A8167R-G is designed to operate from input Voltages down to 1.2V whilst consuming only 5.5mA (typ), so the overall power consumption is minimised to 6.6mW (typ).

The typical application circuit is shown below. Only five (5) external components are necessary:

Those customers wishing to run the LNA at higher input Voltages can implement a Self-Bias circuit as shown below:

Fig 3. XC2401A8167R-G Self-Bias Circuit and 'Rbias' selection table

Ultra Small Solution

The XC2401A8167R-G is available now, in our environmentally friendly USPN-4B02 package, measuring only 0.95mm x 0.75mm with a maximum height of just 0.4mm.