The MAX1472 is the world’s smallest VHF/UHF PLL-based ASK transmitter; it is housed in a tiny 3 mm × 3 mm 8-pin SOT23 package. The transmitter is perfect for low-cost, high-volume applications where space is critical, such as security products and remote sensors operating in the 300- to 450-MHz band. The MAX1472 is designed to run directly from a lithium cell as it operates down to 2.1 V, consuming only 100 nA of current in Standby mode. During transmission, the MAX1472 can output from –10 to 10 dBm of power into a 50-W load. For a 10-dBm power level, the MAX1472 consumes 5.5 mA of current at 315 MHz when using a 50% duty cycle encoding scheme, such as Manchester. Current consumption drops to 3 mA at 0 dBm output. The part can accept data rates up to 100 kbps.

After the MAX1472’s ENABLE pin is activated, it takes only 250 ms for the device’s PLL and crystal to settle so the device is available to transmit. Because the part is targeted at small, portable applications, the MAX1472 accepts crystal frequencies between 9 and 15 MHz.

As the MAX1472 uses a crystal-based PLL, most of the problems of an LC- or SAW-based transmitter are eliminated. The inherent accuracy of the crystal frequency allows for a narrow IF bandwidth in the receiver to improve system sensitivity. With a receiver like the MAX1470 or MAX1473, a 9-dB improvement in sensitivity is possible by narrowing the IF bandwidth from 600 to 50 kHz. Improved sensitivity translates directly to greater range or more reliable transmissions for your product.

Prices start at $1.25 in 1000-piece quantities. An evaluation kit for the MAX1472 is available directly from Maxim and from authorized distributors.

Maxim Integrated Products
(408) 737-7600
www.maxim-ic.com