MICRF507 470MHz to 510MHz Low-Power FSK Transceiver with +10dBm Power Amplifier General Description The MICRF507 is a fully-integrated FSK transceiver with RadioWire +10dBm power amplifier and transmit/receive switch. The device is targeted at automated meter reading (AMR) Features applications in the China Short Range Device (SRD) -113dBm sensitivity at 2.4kbps encoded bit rate frequency band of 470MHz to 510MHz. The device +10dBm power amplifier with seven gain steps supports data rates up to 20kbps with PLL divider modulation and up to 200kbps with VCO modulation. The 12mA receive supply current receiver achieves a sensitivity of -113dBm at a data rate of 21.5mA transmit supply current at +10dBm 2.4kbps while only consuming 12mA of supply current. 0.2A power down current (registers retain settings) The integrated power amplifier (PA) delivers +10dBm of 280A standby current (crystal oscillator enabled) output power while only consuming 21.5mA of supply current. Power down supply current is a low 0.2A while Data rates up to 20kbps with PLL divider modulation retaining register information and a low 280A in standby Data rates up to 200kbps with VCO modulation mode where only the crystal oscillator is enabled. Integrated transmit and receive (T/R) switch The receiver of the MICRF507 utilizes a Zero IF (ZIF) I/Q LNA with bypass mode architecture, integrating a low-noise amplifier (LNA) with Zero IF I/Q receiver architecture bypass mode, I/Q quadrature mixers, three-pole Sallen- IF pre-amplifiers with DC-offset removal Key IF channel pre-filters, and six-pole elliptic switched capacitor IF filters, providing excellent selectivity, adjacent Three-pole Sallen-Key IF channel low-pass pre-filter channel rejection and blocking performance. FSK Six-pole elliptic switched capacitor IF low-pass filter demodulation is implemented digitally and a synchronizer, 50kHz to 350kHz programmable baseband bandwidth when enabled, recovers the received bit clock. A receive 59dB blocking at 1MHz offset signal strength indicator (RSSI) circuit indicates the received signal level over a 50dB range. An integrated 53dB adjacent channel rejection at 500kHz offset Frequency Error Estimator (FEE) and crystal tuning FSK digital demodulator with clock recovery capability allow fine tuning of the RF frequency. 50dB Received Signal Strength Indicator (RSSI) The transmitter of the MICRF507 consists of an FSK Frequency Error Estimator (FEE) modulator and power amplifier with output power Reference crystal tuning capability adjustable from +10dBm to -3.5dBm in seven steps. Modulation can be achieved by applying two sets of PLL 2.0 to 2.5V supply voltage range divider ratios or through direct VCO modulation by varying -40C to +85C operating temperature range VCO tank capacitance. Available in 32-pin QFN package The MICRF507 requires a 2.0V to 2.5V supply voltage, (5.0mm 5.0mm 0.85mm) operates over the -40C to +85C temperature range, and is available in a 32-pin QFN package. Applications China Short Range Device (SRD) Communications Automated Meter Reading (AMR) Advanced Metering Infrastructure (AMI) Wireless Remote Meter Reading RadioWire is a registered trademark of Micrel, Inc. Micrel Inc. 2180 Fortune Drive San Jose, CA 95131 USA tel +1 (408) 944-0800 fax + 1 (408) 474-1000 Micrel, Inc. MICRF507 RadioWire FSK Transceiver Selection Guide ................................................................................................................ 4 Ordering Information ......................................................................................................................................................... 4 Pin Configuration ............................................................................................................................................................... 4 Pin Description ................................................................................................................................................................... 4 Block Diagram .................................................................................................................................................................... 6 Absolute Maximum Ratings .............................................................................................................................................. 7 Operating Ratings .............................................................................................................................................................. 7 Electrical Characteristics .................................................................................................................................................. 7 Functional Description .................................................................................................................................................... 10 Control (3-wire) Interface ...................................................................................................................................... 10 Reading ................................................................................................................................................................. 13 Control Interface Timing ........................................................................................................................................ 14 Power-on Reset .................................................................................................................................................... 14 Clock Generation ............................................................................................................................................................. 15 Crystal Oscillator (XCO) .................................................................................................................................................. 16 BITSYNC CLK (Receiver Bit Synchronization Clock) .......................................................................................... 17 BITRATE CLK (Transmitter Bit Rate Clock) ........................................................................................................ 17 MODULATOR CLK (VCO Modulator Clock) ........................................................................................................ 17 Data Interface and Bit Synchronization ......................................................................................................................... 17 Sync en = 0 .......................................................................................................................................................... 19 Sync en = 1 .......................................................................................................................................................... 19 Additional Considerations in the Use of Synchronizer (Sync en = 1) .................................................................. 19 Frequency Synthesizer .................................................................................................................................................... 20 VCO ....................................................................................................................................................................... 22 Charge Pump ........................................................................................................................................................ 22 PLL Filter ............................................................................................................................................................... 22 Lock Detect ........................................................................................................................................................... 23 Receiver ............................................................................................................................................................................ 24 Front End............................................................................................................................................................... 24 Sallen-Key Filters .................................................................................................................................................. 25 Switched Capacitor Filter ...................................................................................................................................... 25 RSSI ...................................................................................................................................................................... 25 FEE ....................................................................................................................................................................... 26 XCOtune Procedure Example ......................................................................................................................................... 27 Transmitter ........................................................................................................................................................................ 28 Power Amplifier ..................................................................................................................................................... 28 Frequency Modulation ........................................................................................................................................... 29 Divider Modulation ................................................................................................................................................ 30 VCO Modulation and the Modulator ...................................................................................................................... 30 Modulator Filter ..................................................................................................................................................... 32 System Modes and Initialization ..................................................................................................................................... 33 Start-up and Initialization ....................................................................................................................................... 33 Modes of Operation ............................................................................................................................................... 33 Mode Transitions ................................................................................................................................................... 33 Message Coding and Formatting ................................................................................................................................... 34 DC Balanced Line Coding ..................................................................................................................................... 34 Message Formatting: Preamble ............................................................................................................................ 34 Typical Application .......................................................................................................................................................... 35 October 2, 2013 2 Revision 2.2