315MHz/390MHz Dual-Frequency ASK Transmitter

The MAX7058 UHF transmitter alternatively transmits ASK/OOK data at 315MHz or 390MHz using a single crystal. The MAX7058 has internal tuning capacitors at the output of the power amplifier that can be programmed for matching to the antenna or load. The MAX7058 can transmit at a data rate up to 100kbps NRZ (50kbps Manchester coded). Typical transmitted power into a 50Ω load is +10dBm. The MAX7058 operates from +2.1V to +3.6V and draws under 8.0mA of current. The standby current is less than 1µA at room temperature. A 15MHz crystal is used as the reference for 315MHz and 390MHz operation by selecting synthesizer-divide ratios of 21 and 26, respectively.

The MAX7058 is available in a 4mm × 4mm, 24-pin thin QFN package and is specified to operate in the –40°C to +125°C automotive temperature range.

Applications

* Garage Door Openers * Home Automation * RF Remote Controls * Security Systems * Wireless Sensors

* Switched 315MHz/390MHz Carrier Frequency Using One Crystal

* +2.1V to +3.6V Single-Supply Operation

* ASK/OOK Modulation

* Internal Switched Capacitors for Optimum Dual-Frequency Operation

* 8.0mA DC Current Drain (50% Duty Cycle OOK)

* 0.8µA Standby Current

* Small 4mm x 4mm, 24-Pin Thin QFN Package