Set Of Three Devices Eye Low-Cost RF Data Transmission Apps

By combining the U2745B transmitter, U3745BM receiver and a microcontroller, OEMs reportedly can quickly and inexpensively implement certain kinds of RF products. Examples are those optimized to meet the demands of low-cost ASK (amplitude shift keying) transmission systems operating in the 310- to 440-MHz range at low data rates (up to about 10 kbaud).
The U2745B PLL transmitter chip uses a 2.2V-4.0V supply and features a single-ended, open-collector output, a XTO output for clocking the µC, and ESD protection. The IC comes in a SSO16 package and boasts of current consumption as low as 10 µA in sleep mode, 6.2 mA in power-on mode, and 12.5 mA during data transmission.
The U3745BM UHF ASK receiver, in turn, has a fully integrated VCO, uses a 4.5V-5.5V supply, and consumes less than 1 mA (typ.) due to its programmable self-polling capability. It comes housed in a SO20 package. Both transmitter and receiver devices can operate over a -40°C to 85°C range.
Among the candidates for the third, microcontroller member of the 3-device RF data transmission package are various MARC4 4-bit µCs that consume as little as 1.5 mA (typ. at 3V). Pricing of the U2745B transmitter starts at $0.69 each/1,000 and of the U3745BM receiver, $1.49.