The MAX7060 frequency and power-programmable ASK/FSK transmitter operates at 280MHz to 450MHz frequencies. This device incorporates a fully integrated fractional-N synthesizer, which allows the user to set the RF operating frequency to a large fraction of the 280MHz to 450MHz frequency range with a single crystal. For example, the MAX7060 can be tuned from 285MHz to 420MHz with a 15MHz crystal. The RF output power is user-controlled between +14dBm and -14dBm, with a 5V supply or with battery voltages as low as 3.2V. At the minimum specified battery voltage of 2.1V, the RF output power-control range is between +10dBm and -14dBm. To maintain a good output power match across a broad range of frequencies, the MAX7060 also contains a programmable matching capacitor connected in parallel with the power amplifier (PA) output.
ASK modulation is accomplished by switching the PA on and off, so excellent modulation (on/off) ratios are achieved. ASK amplitude shaping is available to reduce the width of the transmission spectrum. FSK modulation is accomplished by changing the coefficients of the high-resolution fractional-N synthesizer, so FSK deviation is extremely accurate. Data rates up to 50kbps Manchester coded for ASK and 70kbps Manchester coded for FSK can be maintained while still satisfying regulatory emission-bandwidth standards. The full set of configuration functions are handled by an on-chip serial peripheral interface (SPI). There is also a manual mode where a limited number of settings can be made directly through selected pins.
The startup time is very short, and data can be transmitted 250µs after the enable command. The MAX7060 operates from a 2.1V to 3.6V supply, or internal regulators can be used for supply voltages between 4.5V and 5.5V. The standby current in the 3V mode is 400nA at room temperature, and can be reduced to 5nA using the low-power shutdown (LSHDN) pin.
The MAX7060 is available in a 24-pin (4mm x 4mm) thin QFN package and is specified for the automotive temperature range from -40°C to +125°C.
Applications
- Garage-Door Openers
- Home and Industrial Automation
- Remote Controls
- Security Systems
- Sensor Networks
