MAX7031:Low-Cost, 308MHz, 315MHz, and 433.92MHz FSK Transceiver with Fractional-N PLL

The MAX7031 crystal-based, fractional-N transceiver is designed to transmit and receive FSK data at factory-preset carrier frequencies of 308MHz, 315MHz, or 433.92MHz with data rates up to 33kbps (Manchester encoded) or 66kbps (NRZ encoded). This device generates a typical output power of +10dBm into a 50Ω load, and exhibits typical sensitivity of -110dBm. The MAX7031 features separate transmit and receive pins (PAOUT and LNAIN) and provides an internal RF switch that can be used to connect the transmit and receive pins to a common antenna. The MAX7031 transmit frequency is generated by a 16-bit, fractional-N, phase-locked loop (PLL), while the receiver's local oscillator (LO) is generated by an integer-N PLL. This hybrid architecture eliminates the need for separate transmit and receive crystal reference oscillators because the fractional-N PLL is preset to be 10.7MHz above the receive LO. Retaining the fixed-N PLL for the receiver avoids the higher current-drain requirements of a fractional-N PLL and keeps the receiver current drain as low as possible. The fractional-N architecture of the MAX7031 transmit PLL allows the transmit FSK signal to be preset for exact frequency deviations, and completely eliminates the problems associated with oscillator-pulling FSK signal generation. All frequency-generation components are integrated on-chip, and only a crystal, a 10.7MHz IF filter, and a few discrete components are required to implement a complete antenna/digital data solution. The MAX7031 is available in a small, 5mm x 5mm, 32-pin, thin QFN package, and is specified to operate in the automotive -40°C to +125°C temperature range.

Key Features
  • +2.1V to +3.6V or +4.5V to +5.5V Single-Supply Operation
  • Single-Crystal Transceiver
  • Factory-Preset Frequency (No Serial Interface Required)
  • FSK Modulation
  • Factory-Preset FSK Frequency Deviation
  • +10dBm Output Power into 50Ω Load
  • Integrated TX/RX Switch
  • Integrated Transmit and Receive PLL, VCO, and Loop Filter
  • > 45dB Image Rejection
  • Typical RF Sensitivity*: -110dBm
  • Selectable IF Bandwidth with External Filter
  • RSSI Output with High Dynamic Range
  • < 12.5mA Transmit-Mode Current
  • < 6.7mA Receive-Mode Current
  • < 800nA Shutdown Current
  • Fast-On Startup Feature, < 250µs
  • Small, 32-Pin, Thin QFN Package
MAX7031: Typical Application Circuit
MAX7031: Typical Application Circuit
Applications/Uses
  • 2-Way Remote Keyless Entry
  • Garage Door Openers
  • Home Automation
  • Local Telemetry Systems
  • Remote Controls
  • Remote Sensing
  • Security Systems
  • Smoke Alarms
DataSheet
titleDownload file
MAX7031 Data SheetMAX7031.pdf
Parametrics
Part NumberSolutionsApplicationsFrequency Range
(MHz)
ISUPPLY
(mA)
Footprint
(mm x mm)
Package/Pins
MAX7031Automotive
ISM, RKE, SRD; 315-433.92MHz Bands
Remote Controls
Remote Sensing
Security Systems
Smoke Alarms
AMR
ISM
Remote Controls
Remote Sensing
Security Systems
Smoke Alarms
308 to 433.9211.65.0 x 5.0TQFN/32
Related Products
  • MAX7030:Low-Cost, 315MHz and 433.92MHz ASK Transceiver with Fractional-N PLL
  • MAX7032:Low-Cost, Crystal-Based, Programmable, ASK/FSK Transceiver with Fractional-N PLL
Ordering Information
Part NumberStatusRecommended ReplacementPackageTempRoHS
MAX7031EVKIT-315No Longer AvailableEVKIT;-40°C to +125°CSee data sheet
MAX7031EVKIT-433No Longer AvailableEVKIT;-40°C to +125°CSee data sheet
MAX7031HATJ17No Longer AvailableMAX7031HATJ17+TQFN,;32 pin;26 mm²-40°C to +125°CNo
MAX7031HATJ17+ActiveTQFN,;32 pin;26 mm²-40°C to +125°CLead Free
MAX7031HATJ17+TNo Longer AvailableQFN;32 pin-40°C to +125°CSee data sheet
MAX7031HATJ17-TNo Longer AvailableMAX7031HATJ17+QFN;32 pin-40°C to +125°CSee data sheet
MAX7031HATJ51+No Longer AvailableTQFN,;32 pin;26 mm²-40°C to +125°CLead Free
MAX7031HATJ51+TNo Longer AvailableTQFN,;32 pin;26 mm²-40°C to +125°CLead Free
MAX7031LATJ+No Longer AvailableTQFN,;32 pin;26 mm²-40°C to +125°CLead Free
MAX7031LATJ+TNo Longer AvailableQFN;-40°C to +125°CSee data sheet
Part NumberStatusRecommended ReplacementPackageTempRoHS
MAX7031MATJ50+ActiveTQFN,;32 pin;26 mm²-40°C to +125°CLead Free
MAX7031MATJ50+TNo Longer AvailableQFN;-40°C to +125°CSee data sheet
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