300MHz–960MHz ASK Transmitter with IC Interface

The MAX41461/MAX41462 is a UHF sub-GHz ISM/SRD transmitter is designed to transmit On-Off Keying (OOK) or Amplitude-Shift Keying (ASK) data in the 286MHz to 960MHz frequency range. It integrates a fractional phase-locked-loop (PLL), so 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 external microcontroller interface. The only frequency-dependent components required are for the external antenna matching network. Optionally, the device can be put into programmable mode and programmed using an I2C interface. The crystal-based architecture of the MAX41461/MAX41462 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. A clock-out signal at 800kHz is also provided.

The MAX41461/MAX41462 provides output power up to +13dBm into a 50Ω load while drawing < 8mA (Manchester coded). 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 MAX41461/MAX41462 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 MAX41461/MAX41462 is available in a 10-pin μMAX package and is specified over the -40°C to +105°C extended temperature range. The MAX41461/MAX41462 has an ESD rating of 2.5kV HBM.

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 x 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

* < 8mA ASK Manchester Coded

* Selectable Standby and Shutdown Modes

* Auto Shutdown at < 20nA (typ) Current

* Ease of Use

* Pin Selectable 300MHz–928MHz Frequencies

* Pin Compatible ASK and FSK Versions

* +1.8V to +3.6V Single-Supply Operation

* Fully Programmable with 400kHz/1MHz I2C Interface