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 50
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
Applications/Uses
+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 50 Load
Integrated TX/RX Switch
Integrated Transmit and Receive PLL, VCO, and
Loop Filter
* Some packages have variations, listed on the drawing. "PkgCode/Variation" tells which variation the product uses. Note that "+", "#", "-" in the part number suffix describes RoHS status. Package drawings may show a different suffix character.
Devices:
1-12
of
12
MAX7031
Free Sample
Buy
Package:
TYPE PINS FOOTPRINT
DRAWING CODE/VAR *
Temp
RoHS/Lead-Free? Materials Analysis
MAX7031EVKIT-315
See data sheet
MAX7031EVKIT-433
See data sheet
MAX7031MATJ50+
THIN QFN;32 pin;26 mm²
Dwg: 21-0140L (PDF)
Use pkgcode/variation: T3255+3*
Download
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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.
