Low-Voltage IF Transceiver with Limiter RSSI and Quadrature Modulator

The MAX2510 is a highly integrated IF transceiver for digital wireless applications. It operates from a +2.7V to +5.5V supply voltage and features four operating modes for advanced system power management. Supply current is reduced to 0.2µA in shutdown mode.

In a typical application, the receiver downconverts a high IF/RF (up to 600MHz) to a low IF (up to 30MHz) using a double-balanced mixer. Additional functions included in the receiver section are an IF buffer that can drive an off-chip filter, an on-chip limiting amplifier offering 90dB of received-signal-strength indication (RSSI), and a robust differential limiter output driver designed to directly drive a CMOS input. The transmitter section upconverts I and Q baseband signals to an IF in the 100MHz to 600MHz range using a quadrature modulator. The transmit output is easily matched to drive a SAW filter with an adjustable output from 0dBm to -40dBm and excellent linearity.

The MAX2511 has features similar to the MAX2510, but upconverts a low IF with an image-reject mixer. The MAX2511 downconverter also offers image rejection with a limiter/RSSI stage similar to that of the MAX2510.

Applications

* 400MHz ISM Transceivers * IF Transceivers * PACS, PHS, DECT, and Other PCS Wireless Handsets and Base Stations * PWT1900, Wireless Handsets, and Base Stations * Wireless Data Links

* +2.7V to +5.5V Single-Supply Operation

* Complete Receive Path: 600MHz (max) 1st IF to 30MHz (max) 2nd IF

* Unique, Wide-Dynamic-Range Downconverter Mixer Offers -8dBm IIP3, 11dB NF

* 90dB Dynamic-Range Limiter with High-Accuracy RSSI Function

* Differential Limiter Output Directly Drives CMOS Input

* 100MHz to 600MHz Transmit Quadrature Modulator with 41dB Sideband Suppression

* 40dB Transmit Gain-Control Range; Up to +1dBm Output Power

* Advanced Power Management (four modes)

* 0.2µA Shutdown Supply Current