300MHz–960MHz (G)FSK Transmitter with IC Interface

The MAX41463/MAX41464 is a UHF sub-GHz ISM/SRD transmitter designed to transmit Frequency-Shift Keying (FSK), or Gaussian (G)FSK (or 2GFSK) data in the 286MHz to 960MHz frequency range. It integrates a fractional phase-locked-loop (PLL) so that a single, low-cost crystal can be used to generate commonly used world-wide sub-GHz frequencies. The fast response time of the PLL allows for frequency-hopping spread spectrum protocols for increased range and security. The chip also features preset modes with pin-selectable frequencies so that only one wire is required for an external microcontroller interface. The only frequency-dependent components required are for the external antenna-matching network. A buffered clock-out signal at 800kHz is also provided. Optionally, the device can be put into programmable mode and programmed using an I2C interface. The crystal-based architecture of the MAX41463/MAX41464 eliminates many of the common problems with SAW-based transmitters by providing greater modulation depth, faster frequency settling, higher tolerance of the transmit frequency, and reduced temperature dependence.

The MAX41463/MAX41464 provides output power up to +13dBm into a 50Ω load while drawing < 12mA at 315MHz. The output load can be adjusted to increase power up to +16dBm, and a PA boost mode can be enabled at frequencies above 850MHz to compensate for losses. The PA output power can also be controlled using programmable register settings in I2C mode.

The MAX41463/MAX41464 also features single-supply operation from +1.8V to +3.6V. The device has an auto-shutdown feature to extend battery life and a fast oscillator wake-up with data activity detection.

The MAX41463/MAX41464 is available in a 10-pin µMAX package and is specified over the −40℃ to +105℃ extended temperature range.

Design Solution: How to Maximize the Wireless Power Range of Your UHF Sub-GHz Short-Range Device ›

Applications

* Automatic Meter Reading (AMR) * Building Automation and Security * Garage Door Openers (GDO) * Internet of Things (IoT) * Radio Control Toys * Remote and Passive Keyless Entry (RKE/PKE) * Tire Pressure Monitoring Systems (TPMS) * Wireless Sensors and Alarms

* Low Implementation Cost

* Bits-to-RF Single Wire Operation* Low Bill-of-Materials (BOM)* Uses Single, Low-Cost, 16MHz Crystal* Small 3mm × 3mm µMAX-10 Package

* Increased Range, Data Rates, and Security

* Up to +16dBm PA Output Power* Fast Frequency Switching for FHSS/DSSS* Fast-On Oscillator: <250µs Startup Time* Up to 200kbps NRZ Data Rate

* Extend Battery Life with Low Supply Current

* < 12mA Typical Current Consumption at 315MHz* Selectable Standby and Shutdown Modes* Auto Shutdown at < 20nA (typ) Current

* Ease-of-Use

* Pin-Selectable Frequencies* Pin-Compatible ASK and FSK Versions* +1.8V to +3.6V Single-Supply Operation* Fully Programmable with 400kHz/1MHz I2C Interface