MICRF505YML

MICRF505 Micrel MICRF505 868MHz and 915MHz ISM Band Transceiver General Description Features The MICRF505 is a true single chip, frequency shift keying True single chip transceiver (FSK) transceiver intended for use in half-duplex, bidirec- Digital bit synchronizer tional RF links. The multi-channeled FSK transceiver is Received signal strength indicator (RSSI) intended for UHF radio equipment in compliance with the RX and TX power management North American Federal Communications Commission (FCC) Power down function part 15.247 and 249, as well as the European Telecommuni- Reference crystal tuning capabilities cation Standard Institute (ETSI) specification, EN300 220. Baseband shaping Three-wire programmable serial interface The transmitter consists of a PLL frequency synthesizer and Register read back function a power amplifier. The frequency synthesizer consists of a voltage-controlled oscillator (VCO), a crystal oscillator, dual Applications modulus prescaler, programmable frequency dividers, and a Telemetry phase-detector. The loop-filter is external for flexibility and Remote metering can be a simple passive circuit. The output power of the Wireless controller power amplifier can be programmed to seven levels. A lock- Remote data repeater detect circuit detects when the PLL is in lock. In receive mode, Remote control systems the PLL synthesizer generates the local oscillator (LO) signal. Wireless modem The N, M , and A values that give the LO frequency are stored Wireless security system in the N0, M0, and A0 registers. Ordering Information The receiver is a zero intermediate frequency (IF) type which makes channel filtering possible with low-power, integrated Part Number Junction Temp. Range Package low-pass filters. The receiver consists of a low noise amplifier MICRF505BML 40C to +85 C 32-Pin MLF (LNA) that drives a quadrature mixer pair. The mixer outputs feed two identical signal channels in phase quadrature. Each channel includes a pre-amplifier, a third order Sallen-Key RC low-pass filter that protects the following switched-capacitor filter from strong adjacent channel signals, and a limiter. The main channel filter is a switched-capacitor implementation of a six-pole elliptic low pass filter. The cut-off frequency of the Sallen-Key RC filter can be programmed to four different frequencies: 100kHz, 150kHz, 230kHz, and 340kHz. The I and Q channel outputs are demodulated and produce a digital data output. The demodulator detects the relative phase of the I and the Q channel signal. If the I channel signal lags behind the Q channel, the FSK tone frequency is above the LO frequency (data 1). If the I channel leads the Q channel, the FSK tone is below the LO frequency (data 0). The output of the receiver is available on the DataIXO pin. A receive signal strength indicator (RSSI) circuit indicates the received signal level. All support documentation can be found on Micrels web site at www.micrel.com. MicroLeadFrame and MLF are trademarks of Amkor Technology, Inc. Micrel, Inc. 1849 Fortune Drive San Jose, CA 95131 USA tel + 1 (408) 944-0800 fax + 1 (408) 474-1000 MICRF505 Micrel Typical Application M9999-051304 2 May 13, 2004