Three transceiver building blocks operate from supply voltages that range from 1.8 to 5.25 V. The LT5500 receiver front end, the LT5502 quadrature IF demodulator with RSSI, and the LT5503 direct IQ modulator and mixer support IEEE 802.11b-compliant and noncompliant 802.11 systems in the unlicensed 2.4-GHz ISM band, as well as WLAN, WLL, and PC-card modems. Their low-voltage operation reduces RF power consumption and the power supply's size by eliminating the dc-dc convertor and the additional battery.
The LT5500 is a 1.8- to 2.7-GHz receiver front end consisting of a low-noise amplifier, a mixer, and an LO buffer in a 24-lead SSOP package. Also in a 24-lead SSOP package, the LT5502 is a 70- to 400-MHz quadrature IF demodulator that consists of an IF limiter, quadrature down mixers, integrated low-pass filters, and divide-by-two LO buffers. And, the LT5503 front-end transmitter IC operates from 1.2 to 2.7 GHz and contains a high-frequency quadrature modulator with a variable-gain amplifier and a balanced mixer in a 20-lead TSSOP package.
In 1000-piece quantities, the LT5500 costs $3.20, the LT5502 costs $5.25, and the LT5503 is $3.85. Each IC may be purchased separately.
Linear Technology
www.linear.com; (408) 432-1900