Linear Tech RF chipset operates down to 1.8V

Linear Technology Corp. has announced the 1.8GHz to 2.7GHz RF transceiver chipset that operates from 1.8V to 5.25V, and suitable for use in 802.11b-compliant and non-compliant 802.11 systems in the 2.4GHz ISM band, as well as WLAN, WLL, and PC card modems.

The low-voltage operation reduces RF power consumption and the size of the power supply by eliminating the need for a dc/dc converter and/or an additional battery. The 1.8V operating capability is the same as the core voltage supply requirements of system logic ICs such as the baseband processor, DSP, and FPGA.

The chipset consists of the LT5500 receiver front end, LT5502 quadrature IF demodulator with RSSI, and LT5503 direct IQ modulator and mixer.

The LT5500 is a 1.8GHz to 2.7GHz receiver front end consists of an LNA, mixer, and an LO buffer, all packaged in a 24-lead SSOP casing. The LNA can be set to either high gain or low gain mode (13.5dB or -14dB at 2.5GHz), while the mixer has a 5dB conversion gain and IIP3 of 2.5dBm (2.5GHz).

Housed in a 24-lead SSOP casing, the LT5502 integrates an IF limiter, quadrature down mixers, lowpass filters, and divide-by two LO buffers. The IF limiter has an 84dB small-signal gain and a built-in RSSI with >90dB linear range.

The LT5503 is a front-end transmitter IC designed for operation over the 1.2GHz to 2.7GHz frequency range. It contains an HF quadrature modulator with a variable gain amplifier and a balanced mixer in a 20-lead TSSOP.

The modulator includes a 900 phase shifter and signal combiner that allows direct modulation of an RF signal by the baseband I and Q signals.

The LT5500, LT5502, and LT5503 are priced at $3.30, $5.25, and $3.85 each, respectively, in 1,000-piece quantities.