MAX7031

19-3707; Rev 0; 5/05 Low-Cost, 308MHz, 315MHz, and 433.92MHz FSK Transceiver with Fractional-N PLL General Description www.datasheet4u.com 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 *0.2% BER, 4kbps Manchester-encoded data, 280kHz IF BW MAX7031 The MAX7031 crystal-based, fractional-N transceiver is designed to transmit and receive FSK data at factorypreset 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 Ω 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 16bit, fractional-N, phase-locked loop (PLL), while the ...