San Jose, Calif. Atmel Corp. has introduced the third of its MAX-Link series of transceivers designed specifically for WiMAX applications. The AT86RF525B transceiver and its predecessor, the AT86RF535B, use a proprietary internal calibration algorithm that eliminates the need for an external calibration circuit or calibration software.
The MAX-Link transceivers are the only WiMAX specific transceivers on the market today with internal calibration, according to Atmel. Initial startup calibration captures mismatch effects resulting in lower local oscillator leakage and improved image rejection, said Atmel. In addition, the calibration routine is continuously performed between transmit and receive data frames, totally independent from the baseband and media access control (MAC) processor, to optimize the image rejection and LO leakage performance characteristics.
This single-chip transceiver operates at 2.5 GHz with multiple bandwidth options addressing the requirements of WiMAX base stations and subscriber equipment. Internal configuration and control registers can be programmed to integrate with new and existing baseband devices from different vendors.
On-chip integration techniques combine a low-noise amplifier, power amplifier driver, receive/transmit mixer, receive/transmit filters, voltage-controlled oscillator, synthesizer, receive gain control, and transmit power control all completely digitally controlled. The fully differential design of the transceiver can be configured for either low-IF or zero-IF applications and requires no external filters. The RF reference design incorporates a power amplifier including antenna diversity in a footprint of 40 x 35 mm on a 4-layer printed-circuit-board (PCB) with components on only one side.
The fractional-N synthesizer in the AT86RF525B uses a unique phase interpolation divider (PID) rather than the more conventional modulus divider architecture. The PID allows for very good frequency resolution and fast tuning speed, said Atmel. The calibrated voltage control oscillator (VCO) can be tuned in less than 10 us to support 100 MHz hybrid frequency division duplexing (HFDD) operations. The synthesizer has the speed and power advantages of an asynchronous divider and is fully programmable within the frequency range of the radio.
Pricing: Starts at $14.50 in quantities of 10,000.
Availability: Available now.
Product information: AT86RF525B
Atmel Corp., 1-408-441-0311, www.atmel.com