900MHz image-reject transceiver in 28-SSOP
The MAX2421EAI is a 900MHz image-reject transceiver from Analog Devices, designed for full-duplex communication links. It integrates a single driver and receiver pair (1/1) in a 28-SSOP package with a 0.209-inch body width and 5.30mm height. The supply voltage range of 2.7V to 4.8V covers common 3.3V and 3.6V rails, but the 4.8V upper limit means a 5V rail needs a series regulator or a divider — the part is not 5V-tolerant on VCC.
Full-duplex single-channel link
Full-duplex operation means the MAX2421EAI can transmit and receive simultaneously on a single RF channel, which halves the antenna count compared to half-duplex designs that need a T/R switch. The image-reject architecture reduces the need for a bulky SAW filter at the mixer output, saving board area and BOM cost in the 900 MHz ISM-band receiver chain.
Active production, RoHS non-compliant
If your BOM requires RoHS-10 or REACH compliance, you will need a waiver or an alternate part — confirm with your compliance team before committing the line.