300MHz to 450MHz High-Efficiency, Crystal-Based +13dBm ASK Transmitter

Low-Power, 300MHz to 450MHz, Crystal-Based ASK Transmitter has +13dBm Output Power


The MAX7044 crystal-referenced phase-locked-loop (PLL) VHF/UHF transmitter is designed to transmit OOK/ASK data in the 300MHz to 450MHz frequency range. The MAX7044 supports data rates up to 100kbps, and provides output power up to +13dBm into a 50Ω load while only drawing 7.7mA at 2.7V.

The crystal-based architecture of the MAX7044 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 MAX7044 also features a low supply voltage of +2.1V to +3.6V. These improvements enable better overall receiver performance when using the MAX7044 together with a superheterodyne receiver such as the MAX1470 or MAX1473.

A simple, single-input data interface and a buffered clock-out signal at 1/16th the crystal frequency make the MAX7044 compatible with almost any microcontroller or code-hopping generator.

The MAX7044 is available in an 8-pin SOT23 package and is specified over the -40°C to +125°C automotive temperature range.

MAX7044: Functional Diagram MAX7044: Functional Diagram Enlarge+

Key Features

  • +2.1V to +3.6V Single-Supply Operation
  • OOK/ASK Transmit Data Format
  • Up to 100kbps Data Rate
  • +13dBm Output Power into 50Ω Load
  • Low 7.7mA (typ) Operating Supply Current*
  • Uses Small, Low-Cost Crystal
  • Small 3mm x 3mm 8-Pin SOT23 Package
  • Fast-On Oscillator: 250µs Startup Time


  • Garage Door Openers
  • Remote Keyless Entry (RKE)
  • RF Remote Controls
  • Security Systems
  • Tire-Pressure Monitoring (TPM)
  • Wireless Computer Peripherals
  • Wireless Game Consoles
  • Wireless Sensors
Part Number Solutions Applications Band/ Freq.
(mm x mm)
Package/Pins Budgetary
See Notes
MAX7044  300 to 450MHz-ISM RKE
Garage Door Openers
Home Automation
ISM (Europe)
RF Remote Controls
Security Systems
300 to 450 3.0 x 3.0
$1.32 @1k
See All ISM RF Transmitters (12)
Pricing Notes:
This pricing is BUDGETARY, for comparing similar parts. Prices are in U.S. dollars and subject to change. Quantity pricing may vary substantially and international prices may differ due to local duties, taxes, fees, and exchange rates. For volume-specific and version-specific prices and delivery, please see the price and availability page or contact an authorized distributor.

MAX7044EVKIT: Evaluation Kit for the MAX7044

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