AN611 Datasheet | Maxim Integrated

Overview TD-SCDMA is the third-generation (3G) cellular phone standard currently under development in China. In November 1999, the TD-SCDMA standard was adopted by the ITU as one of the options in the 3GPP mobile munication standard. TD-SCDMA bines time-division duplex (TDD) and CDMA with up-link (reverse-link) synchronization, a software radio, and a smart antenna, to increase channel capacity and improve bandwidth efficiency. In the radio section of the handset, the TD-SCDMA radio section requires fast switching time, high dynamic range, and high linearity in both the transmitter and receiver sections. Maxim's chipset delivers the highest performance, the smallest implementation size, and the least expensive radio solution available in the TD-SCDMA handset market. The following block diagram shows a typical application. Transmitter The MAX236X is a plete quadrature transmitter, including a quadrature modulator, variablegain IF and RF amplifiers, an image-rejecting upconverting mixer, a dual RF and IF synthesizer, and a dual-band power amplifier (PA) driver amplifier. It is the ideal transmitter for TD-SCDMA because of these features : q q q q Output power of +8d Bm with excellent ACPR A 100d B power-control range Dual integer-N synthesizers for IF and RF An image-reject upconverting mixer, which saves one SAW filter q q q Power-supply current dropping as the RF output power is reduced Low-noise power during the power-down mode Availability in a 48-pin QFN package (7mm x 7mm) Power Amplifier The MAX229X is a linear amplifier optimized for TD-SCDMA application. It can deliver +26d Bm output power with 30% power-added efficiency (PAE) and 37d Bc ACLR1. Receivers The MAX2388 includes a low-noise amplifier (LNA), a downconverter, and a local oscillator (LO) buffer amplifier. Requiring ultra-low current consumption (9.9m A), the device is ideal for TDSCDMA application. The LNA delivers fixed gains of 15d B and -3d B, and it has a 1.7d B noise figure (NF) and +4.2d Bm IIP3...