300MHz To 450MHz Frequency-Programmable ASK/FSK Transmitter

The MAX7057 frequency-programmable UHF transmit- ter is designed to transmit ASK/FSK data at a wide range of frequencies from 300MHz to 450MHz. The MAX7057 has internal tuning capacitors at the output of the power Amplifier that are programmable for match- ing to an Antenna or load. This allows the user to change to a new frequency and match the Antenna at the new frequency simultaneously. The MAX7057 trans- mits at a data rate up to 100kbps nonreturn-to-zero (NRZ) (50kbps Manchester coded). Typical transmitted power into a 50 load is +9.2dBm with a +2.7V supply. The device operates from +2.1V to +3.6V and typically draws under 12.5mA of current in FSK mode (8.5mA in ASK mode) when the antenna-matching network is designed to operate over the 315MHz to 433.92MHz frequency range. For narrower operating frequency ranges, the matching network CAN be redesigned to improve efficiency. The standby current is less than 1A at room temperature. The MAX7057 is available in a 16-pin SO package and is specified to operate in the -40C to +125C automo tive temperature range. By Maxim Integrated Products