MICRF600 902-928MHz ISM Band Transceiver Module General Description The MICRF600 is a self-contained frequency shift keying (FSK) transceiver module, intended for use in half-duplex, bidirectional RF links. The multi-channeled FSK transceiver module is intended for UHF radio equipment in compliance with the North American Federal Communications Commission (FCC) part 15.247 and 249. The transmitter consists of a fully programmable PLL frequency synthesizer and power amplifier. The frequency synthesizer consists of a voltage-controlled oscillator (VCO), a crystal oscillator, dual modulus prescaler, programmable frequency dividers, and a phase-detector. The output power of the power amplifier can be programmed to seven levels. A lock-detect circuit detects when the PLL is in lock. In receive mode, the PLL synthesizer generates the local oscillator (LO) signal. The N, M, and A values that give the LO frequency are stored in the N0, M0, and A0 registers. The receiver is a zero intermediate frequency (IF) type that makes channel filtering possible with low-power, integrated low-pass filters. The receiver consists of a low noise amplifier (LNA) that drives a quadrature mix 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 350kHz. 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, then 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 Micrel’s web site at: www.micrel.com. RadioWire® Module Features • • • • • • • • • • • • “Drop in” RF solution Small size: 11.5x14.1mm RF tested FCC Compliant Low Power Surface Mountable Tape & Reel Digital Bit Synchronizer Received Signal Strength Indicator (RSSI) RX and TX power management Power down function Register read back function Applications • • • • • • • Telemetry Remote metering Wireless controller Remote data repeater Remote control systems Wireless modem Wireless security system RadioWire® is a trademark of Micrel, Inc Power, Connect and Protect 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 • http://www.micrel.com September 2005 M9999-091905 Micrel, Inc. MICRF600 Contents General Description ................................................................................................................................................................ 1 Features .................................................................................................................................................................................. 1 Applications ............................................................................................................................................................................. 1 Contents .................................................................................................................................................................................. 2 RadioWire® RF Module Selection Guide................................................................................................................................. 3 Ordering Information ............................................................................................................................................................... 3 Block Diagram ......................................................................................................................................................................... 3 Pin Configuration..................................................................................................................................................................... 4 Pin Description ........................................................................................................................................................................ 4 Absolute Maximum Ratings(1) ................................................................................................................................................. 5 Operating Ratings(2) ................................................................................................................................................................ 5 Electrical Characteristics......................................................................................................................................................... 5 Programming........................................................................................................................................................................... 7 General ............................................................................................................................................................................... 7 Writing to the Control Registers in MICRF600 ................................................................................................................... 8 Writing to a Single Register ................................................................................................................................................ 8 Writing to All Registers ....................................................................................................................................................... 8 Writing to n Registers Having Incremental Addresses ....................................................................................................... 9 Reading from the Control Registers in MICRF600 ............................................................................................................. 9 Reading n Registers from MICRF600................................................................................................................................. 9 Programming Interface Timing.............................................................................................................................................. 10 Programming Summary.................................................................................................................................................... 11 Frequency Synthesizer ......................................................................................................................................................... 11 Crystal Oscillator (XCO) ................................................................................................................................................... 11 VCO .................................................................................................................................................................................. 12 Lock Detect ....................................................................................................................................................................... 12 Modes of Operation............................................................................................................................................................... 12 Transceiver Sync/Non-Synchronous Mode ...................................................................................................................... 13 Data Interface ................................................................................................................................................................... 13 Receiver ................................................................................................................................................................................ 13 Front End .......................................................................................................................................................................... 14 Sallen-Key Filters.............................................................................................................................................................. 14 Switched Capacitor Filter.................................................................................................................................................. 14 RSSI.................................................................................................................................................................................. 14 FEE ................................................................................................................................................................................... 15 Bit Synchronizer................................................................................................................................................................ 15 Transmitter ............................................................................................................................................................................ 16 Power Amplifier................................................................................................................................................................. 16 Frequency Modulation ...................................................................................................................................................... 16 Using the XCO-tune Bits ....................................................................................................................................................... 16 Application Circuit Illustration ................................................................................................................................................ 17 Assembling the MICRF600 ................................................................................................................................................... 17 Recommended Reflow Temperature Profile .................................................................................................................... 17 Shock/Vibration during Reflow.......................................................................................................................................... 17 Handassembling the MICRF600....................................................................................................................................... 17 Layout.................................................................................................................................................................................... 18 Recommended Land Pattern............................................................................................................................................ 18 Layout Considerations ...................................................................................................................................................... 18 Package Dimensions ............................................................................................................................................................ 19 Tape Dimensions .................................................................................................................................................................. 19 September 2005 2 M9999-091905 Micrel, Inc. MICRF600 RadioWire® RF Module Selection Guide Device Frequency Range Data Rate Receive Supply Voltage Transmit Modulation Type Package MICRF600 902-928 MHz <20 kbps 13.5 mA 2.0-2.5 v 28 mA FSK 11.5x14.1 mm MICRF610 868-870 MHz <15 kbps 13.5 mA 2.0-2.5 v 28 mA FSK 11.5x14.1 mm MICRF620 430-440 MHz <20 kbps 12.0 mA 2.0-2.5 v 24 mA FSK 11.5x14.1 mm RFB433B 430-440 MHz 19.2 kbaud 8 mA 2.5-3.4 V 42 mA FSK 1”x1” RFB868B 868-870 MHz 19.2 kbaud 10 mA 2.5-3.4 V 50 mA FSK 1”x1” RFB915B 902-928 MHz 19.2 kbaud 10 mA 2.5-3.4 V 50 mA FSK 1”x1” Ordering Information Part Number Junction Temp. Range(1) Package MICRF600 TR –20° to +70°C 11.5 x 14.1mm Block Diagram SCLK IO IFAMP LO-Buffer PA-buffer PA RSSI Deviation control DIV 2 CS Control logic ANT Clock recovery Demodulator LNA Main filter Sallen-key Modulator IFAMP Main filter Sallen-key DataIXO DataClk RSSI LDout Frequency Synthesiser VCO XCO Bias MICRF600 September 2005 3 M9999-091905 Micrel, Inc. MICRF600 Pin Configuration 16 2 1 VDD 15 3 CS GND 14 4 SCLK ANT 13 5 IO GND 12 6 DataIXO GND 11 7 10 9 DataClk 8 MICRF600 TR 11.5 x 14.1 mm (Top view) Pin Description Pin Number Pin Name Type 1 NC Not connected 2 NC Not connected 3 CS 4 SClk I Clock, three wire programming interface 5 IO I/O Data, three wire programming interface 6 DataIXO I/O Data receive/transmit, bi-directional 7 DataClk O Data clock receive/transmit I Pin Function Chip select, three wire programming interface 8 LD O Lock detect 9 RSSI O Receive signal strength indicator 10 GND Ground 11 GND Ground 12 GND Ground 13 ANT 14 GND I/O RF In/Out Ground 15 VDD VDD (2.0-2.5V) 16 GND Ground September 2005 4 M9999-091905 Micrel, Inc. MICRF600 Absolute Maximum Ratings(1) Operating Ratings(2) Supply Voltage (VDD)...................................................+3.3V Voltage on any pin (GND = 0V). ..................... -0.3V to 2.7V Lead Temperature (soldering, 5 sec.) ......................+225°C Storage Temperature (Ts) ............................-30°C to +85°C ESD Rating(3) ..................................................................2kV Supply voltage (VIN) ..................................+2.0V to +2.5V RF Frequencies................................. 902MHz to 928MHz Data Rate (NRZ) ................................................ <20 kbps Ambient Temperature (TA) .......................–20°C to +70°C Electrical Characteristics fRF = 915MHz, Data rate = 20kbps, VDD = 2.5V; TA = 25°C, bold values indicate –20°C< TA < +70°C, unless noted. Symbol Parameter Condition Min Power Supply Typ 2.0 Max 2.5 Units V Power Down Current 0.3 µA Standby Current 280 µA 16 MHz VCO and PLL Section Tunable with on-chip cap bank Crystal Oscillator Frequency Tuning range Crystal Initial Tolerance Crystal Temperature Tolerance -30 +40 ppm -10 +10 ppm +10 ppm -10 Switch Time Crystal Oscillator Start-Up Time Rx 915MHz – Rx 915.5MHz 250 µs Rx 903MHz – Rx 926MHz 850 µs Rx – Tx, same frequency 200 µs Tx – Rx, same frequency, time to good data 300 µs Standby – Rx, 1.0 ms Standby – Tx 1.0 ms XCO_tune=13 750 µs RLOAD = 50Ω, Pa2-0-111 9 dBm Transmit Section Output Power Output Power Tolerance Tx Current Consumption Tx Current Consumption Variation Binary FSK Frequency Separation (5) RLOAD = 50Ω, Pa2-0-001 -7 dBm Over temperature range 2 dB Over power supply range 3 dB RLOAD = 50Ω, PA2_0: 111 28 mA RLOAD = 50Ω, PA2_0: 001 14 mA RLOAD = 50Ω, PA2_0: 111 2.5 mA Limited by receiver BW 20 400 kHz Data Rate(5) NRZ 0 20 kbps Occupied bandwidth 20kbps, β = 10 (±100kHz), 20dBc (RBW=10kHz) 2nd Harmonic rd 3 Harmonic Spurious Emission < 902 MHz FCC part 15, RLOAD = 50Ω Spurious Emission > 928 MHz September 2005 5 320 kHz -20 dBc -41.2 dBm -49.2 dBm -41.2 dBm M9999-091905 Micrel, Inc. Symbol MICRF600 Parameter Condition Min Typ Max Units Receive Section Rx Current Consumption Rx Current Consumption Variation Receiver Sensitivity Receiver Maximum Input Power Receiver Sensitivity Tolerance All functions on 13.5 mA LNA bypass 11.5 mA Switch cap filter bypass with LNA 11.5 mA 4 mA 2.4 kbps, β = 16, SC=50 kHz Over temperature -111 dBm 4.8 kbps, β = 16, SC=50 kHz -110 dBm 4.8 kbps, β = 4, SC=50 kHz -109 dBm 19.2 kbps, β =8, SC=200 kHz -107 dBm 19.2 kbps, β =2, SC=67 kHz -104 dBm 19.2 kbps, β = 10 -10 dBm Over temperature 4 dB Over power supply range 1 dB Receiver Bandwidth 50 19.2 kbps, β = 8, SC=133 kHz Co-Channel Rejection 200 kHz spacing Adjacent Channel Rejection 500 kHz spacing TBD TBD dB Offset ±1MHz 55 dB Offset ±2MHz 58 dB Offset ±5MHz 48 dB Offset ±10MHz 50 dB Offset ±30MHz 60 dB 1dB Compression Input IP3 2 tones with 1MHz separation Input IP2 -35 dB -25 dBm TBD LO Leakage dBm -90 Spurious Emission kHz TBD 1 MHz spacing Desired signal: 19.2 kbps, β =8, 3dB above sens, SC=133 kHz Blocking 350 -9 dBm < 902 MHz -49.2 dBm > 928 MHz -41.1 dBm Input Impedance(5) Ω RSSI Dynamic Range RSSI Output Range 50 dB Pin = -100 dBm 1.2 V Pin = -60 dBm 2.2 V Digital Inputs/Outputs Logic Input High 0.7VDD VDD V Logic Input Low 0 0.3VDD V 10 MHz 55 % Clock/Data Frequency(4) (4) Clock/Data Duty Cycle Notes: 1. 2. 3. 4. 45 Exceeding the absolute maximum rating may damage the device. The device is not guaranteed to function outside its operating rating. Devices are ESD sensitive. Handling precautions recommended. Human body model, 1.5k in series with 100pF. Guaranteed by design. September 2005 6 M9999-091905 Micrel, Inc. MICRF600 Programming General The MICRF600 functions are enabled through a number of programming bits. The programming bits are organized as a set of addressable control registers, each register holding 8 bits. There are 23 control registers in total in the MICRF600, and they have addresses ranging from 0 to 22. The user can read all the control registers. The user can write to the first 22 registers (0 to 21); the register 22 is a read-only register. All control registers hold 8 bits and all 8 bits must be written to when accessing a control register, or they will be read. Some of the registers do not utilize all 8 bits. The value of an unused bit is “don’t care.” The control register with address 0 is referred to as ControlRegister0, the control register with address 1 is ControlRegister1 and so on. A summary of the control registers is given in the table below. In addition to the unused bits (marked with”-“) there are a number of fixed bits (marked with “0” or “1”). Always maintain these as shown in the table. The control registers in MICRF600 are accessed through a 3-wire interface; clock, data and chip select. These lines are referred to as SCLK, IO, and CS, respectively. This 3wire interface is dedicated to control register access and is referred to as the control interface. Received data (via RF) and data to transmit (via RF) are handled by the DataIXO and DataClk (if enabled) lines; this is referred to as the data interface. The SCLK line is applied externally; access to the control registers are carried out at a rate determined by the user. The MICRF600 will ignore transitions on the SCLK line if the CS line is inactive. The MICRF600 can be put on a bus, sharing clock and data lines with other devices. All control registers should be written to after a battery reset. During operation, it is sufficient to write to one register only. The MICRF600 will automatically enter power down mode after a battery reset. Address Data A6…A0 D7 D6 D5 D4 D3 D2 0000000 LNA_by PA2 PA1 0000001 ‘1’ ‘0’ ‘0’ PA0 Sync_en Mode1 Mode0 ‘1’ ‘0’ RSSI_en LD_en PF_FC1 PF_FC0 0000010 ‘0’ ‘SC_by’ ‘0’ ‘PA_by’ ‘0’ ‘0’ ‘0’ ‘0’ 0000011 ‘1’ ‘1’ ‘0’ VCO_IB2 VCO_IB1 VCO_IB0 VCO_freq1 VCO_freq0 0000100 ‘0’ - ‘0’ - ‘0’ ‘0’ ‘0’ ‘1’ ‘0’ ‘0’ ‘0’ ‘0’ 0000101 0000110 - 0001000 ‘1’ ‘1’ 0001001 ‘0’ 0001010 - ‘0’ ‘0’ ‘0’ 0000111 BitRate_clkS1BitRate_clkS0 RefClk_K5 RefClk_K4 D1 D0 ‘0’ ‘0’ ‘0’ ‘0’ BitSync_clkS2 BitSync_clkS1 BitSync_clkS0 BitRate_clkS2 RefClk_K3 RefClk_K2 RefClk_K1 RefClk_K0 ScClk5 ScClk4 ScClk3 ScClk2 ScClk1 ScClk0 ‘1’ ‘1’ XCOtune4 XCOtune3 XCOtune2 XCOtune1 XCOtune0 - A0_5 A0_4 A0_3 A0_2 A0_1 A0_0 0001011 - - - - N0_11 N0_10 N0_9 N0_8 0001100 N0_7 N0_6 N0_5 N0_4 N0_3 N0_2 N0_1 N0_0 0001101 - - - - M0_11 M0_10 M0_9 M0_8 0001110 M0_7 M0_6 M0_5 M0_4 M0_3 M0_2 M0_1 M0_0 0001111 - - A1_5 A1_4 A1_3 A1_2 A1_1 A1_0 0010000 - - - - N1_11 N1_10 N1_9 N1_8 0010001 N1_7 N1_6 N1_5 N1_4 N1_3 N1_2 N1_1 N1_0 0010010 - - - - M1_11 M1_10 M1_9 M1_8 0010011 M1_7 M1_6 M1_5 M1_4 M1_3 M1_2 M1_1 M1_0 0010100 ‘1’ ‘0’ ‘1’ ‘1’ ‘0’ ‘1’ ‘0’ ‘1’ 0010101 - - - - FEEC_3 FEEC_2 FEEC_1 FEEC_0 0010110 FEE_7 FEE_6 FEE_5 FEE_4 FEE_3 FEE_2 FEE_1 FEE_0 Table 1. Control Registers in MICRF600 September 2005 7 M9999-091905 Micrel, Inc. Writing to the Control Registers in MICRF600 Writing: A number of octets are entered into MICRF600, followed by a load-signal to activate the new setting. Making these events is referred to as a “write sequence.” It is possible to update all, 1, or n control registers in a write sequence. The address to write to (or the first address to write to) can be any valid address (0-21). The IO line is always an input to the MICRF600 (output from user) when writing. MICRF600 Field Comments Address: 7 bit = A6, A5, …A0 (A6 = msb. A0 = lsb) R/W bit: “0” for writing Values: 8 bits = D7, D6, …D0 (D7 = msb, D0 = lsb) Table 3. “Address” and “R/W bit” together make 1 octet In addition, 1 octet with programming bits is entered. Totally, 2 octets are clocked into the MICRF600. How to write: What to write: • The address of the control register to write to (or if more than 1 control register should be written to, the address of the 1st control register to write to). • A bit to enable reading or writing of the control registers. This bit is called the R/W bit. • The values to write into the control register(s). Field A 7-bit field, ranging from 0 to 21. MSB is written first. R/W bit: A 1-bit field, = “0” for writing Values: A number of octets (1-22 octets). MSB in every octet is written first. The first octet is written to the control register with the specified address (=”Address”). The next octet (if there is one) is written to the control register with address = “Address + 1” and so on. Table 2. Writing to the Control Registers How to write: Bring CS active to start a write sequence. The active state of the CS line is “high.” Use the SCLK/IO serial interface to clock “Address” and “R/W” bit and “Values” into the MICRF600. MICRF600 will sample the IO line at negative edges of SCLK. Make sure to change the state of the IO line before the negative edge. Refer to figures below. Bring CS inactive to make an internal load-signal and complete the write-sequence. • Use SCLK and IO to clock in the 2 octets • Bring CS low CS SCLK A6 IO A5 A0 Address of register i RW D7 D6 D2 D1 D0 Writing to All Registers After a power-on, all writable registers must be written. This is described here: Writing to all register can be done at any time. To get the simplest firmware, always write to all registers. The price to pay for the simplicity is increased write-time, which leads to increased time for changing the way the MICRF600 works. What to write Field Write to a number of control registers when the registers have non-incremental addresses. September 2005 Data to write into register i Internal load pulse made here In Figure 1, IO is changed at positive edges of SCLK. The MICRF600 samples the IO line at negative edges. The value of the R/W bits is always “0” for writing. Write to a number of control registers (0-22) when the registers have incremental addresses (write to 1, all or n registers) Writing to a Single Register Writing to a control register with address “A6. A5, …A0” is described here. During operation, writing to 1 register is sufficient to change the way the transceiver works. Typical example: Change from receive mode to power-down. RW Figure 1. How to write to a single Control Register The two different ways to “program the chip” are: • Bring CS high Comments Address: • • Comments Address: ‘000000’ (address of the first register to write to, which is 0) R/W bit: “0” for writing Values: 1st Octet: wanted values for ControlRegister0. 2nd Octet: wanted values for ControlRegister1 and so on for all of the octets. So the 22nd octet: wanted values for ControlRegister21. Refer to the specific sections of this document for actual values. Table 4. “Address” and “R/W bit” together make 1 octet In total, 23 octets are clocked into the MICRF600. 8 M9999-091905 Micrel, Inc. MICRF600 How to write: Refer to the figure in the next section, “Writing to n registers having incremental addresses”. Reading from the Control Registers in MICRF600 The “read-sequence” is: 1. Enter address and R/W bit 2. Change direction of IO line 3. Read out a number of octets and change IO direction back again. Writing to n Registers Having Incremental Addresses In addition to entering all bytes, it is also possible to enter a set of n bytes, starting from address i = “A6, A5, … A0”. Typical example: Clock in a new set of frequency dividers (i.e. change the RF frequency). “Incremental addresses”. Registers to be written are located in i, i+1, i+2. It is possible to read all, 1 or n registers. The address to read from (or the first address to read from) can be any valid address (0-22). Reading is not destructive, i.e. values are not changed. The IO line is output from the MICRF600 (input to user) for a part of the read-sequence. Refer to procedure description below. What to write: • Bring CS high • Use SCLK and IO to clock in the 23 octets • Bring CS low Field Comments A read-sequence is described for reading n registers, where n is number 1-23. Address: 7 bit = A6, A5, …A0 (A6 = msb. A0 = lsb) (address of first byte to write to) Reading n Registers from MICRF600 R/W bit: “0” for writing Values: n* 8 bits = CS D7, D6, …D0 (D7 = msb, D0 = lsb) (written to control reg. with address ”i”) SCLK D7, D6, …D0 (D7 = msb, D0 = lsb) (written to control reg. with address ”i+1”) IO D7, D6, …D0 (D7 = msb, D0 = lsb) (written to control reg. with address ”i+n-1”) A5 A0 Address of register i RW D7 D6 D0 RWData read from reg. i Simple time Table 5. “Address” and “R/W bit” together make 1 octet In addition, n octets with programming bits are entered. Totally. 1 +n octets are clocked into the MICRF600. IO Input IO Output Figure 3. How to read from many Control Registers How to write: • Bring CS high • Use SCLK and IO to clock in the 1 + n octets • Bring CS low In Figure 1, IO is changed at positive edges of SCLK. The MICRF600 samples the IO line at negative edges. The value of the R/W bits is always “0” for writing. In Figure 3, 1 register is read. The address is A6, A5, … A0. A6 = msb. The data read out is D7, D6, …D0. The value of the R/W bit is always “1” for reading. SCLK and IO together form a serial interface. SCLK is applied externally for reading as well as for writing. • Bring CS active • Enter address to read from (or the first address to read from) (7 bits) and • The R/W bit = 1 to enable reading • Make the IO line an input to the user (set pin in tristate) • Read n octets. The first rising edge of SCLK will set the IO as an output from the MICRF600. MICRF will change the IO line at positive edges. The user should read the IO line at the negative edges. • Make the IO line an output from the user again. CS SCLK IO A6 A6 A5 A0 Address of first register to write to, register i RW D7 D6 RW Data to write into register i D2 D1 D0 Data to write into register i+1 Internal load pulse made here Figure 2. How to write to many Control Registers September 2005 9 M9999-091905 Micrel, Inc. MICRF600 Programming Interface Timing Figure 4 and Table 6 show the timing specification for the 3-wire serial programming interface. Tcsr traise tfall Tper Thigh Tread Tlow Tscl Twrite SCLK CS IO A6 A5 A0 RW D7 Address Register D6 D2 D1 D0 Data Register LOAD Figure 4. Programming Interface Timing Values Symbol Parameter Tper Min. period of SCLK (Voltage dividers on IO lines will slow down the write/read frequency) 50 ns Thigh Min. high time of SCLK 20 ns Tlow Min. low time of SCLK 20 tfall Max. time of falling edge of SCLK Min. trise Max. time of rising edge of SCLK Tcsr Max. time of rising edge of CS to falling edge of SCLK Typ. Max. Units ns 1 µs 1 µs 0 ns Tcsf Min. delay from rising edge of CS to rising edge of SCLK 5 ns Twrite Min. delay from valid IO to falling edge of SCLK during a write operation 0 ns Tread Min. delay from rising edge of SCLK to valid IO during a read operation (assuming load capacitance of IO is 25pF) 75 ns Time from power up to first rising edge of CS 3.4 ms (Assuming Vdd rail rise time of 100 µsec) Table 6. Timing Specification for the 3-wire Programming Interface September 2005 10 M9999-091905 Micrel, Inc. Programming Summary MICRF600 Frequency Synthesizer • Use CS, SCLK, and IO to get access to the control registers in MICRF600. A6…A0 D7 D6 D5 D4 D3 D2 D1 D0 0001010 - - A0_5 A0_4 A0_3 A0_2 A0_1 A0_0 • SCLK is user-controlled. 0001011 - - - - N0_11 N0_10 N0_9 N0_8 0001100 N0_7 N0_6 N0_5 N0_4 N0_3 N0_2 N0_1 N0_0 • Write to the MICRF600 at positive edges (MICRF600 reads at negative edges). • Read from the MICRF600 at negative edges (MICRF600 writes at positive edges) • After power-on: Write to the complete set of control registers. • Address field is 7 bits long. Enter msb first. • R/W bit is 1 bit long (“1” for read, “0” for write) • Address and R/W bit together make 1 octet • All control registers are 8 bits long. Enter/read msb in every octet first. • Always write 8 bits to/read 8 bits from a control register. This is the case for registers with less than 8 used programming bits as well. • Writing: Bring CS high, write address and R/W bit followed by the new values to fill into the addressed control register(s) and bring CS low for loading, i.e., activation of the new control register values. • Reading: Bring CS high, write address and R/W bit, set IO as an input, read present contents of the addressed control register(s), bring CS low and set IO an output. 0001101 - - - - M0_11 M0_10 M0_9 M0_8 0001110 M0_7 M0_6 M0_5 M0_4 M0_3 M0_2 M0_1 M0_0 0001111 - - A1_5 A1_4 A1_3 A1_2 A1_1 A1_0 0010000 - - - - N1_11 N1_10 N1_9 N1_8 0010001 N1_7 N1_6 N1_5 N1_4 N1_3 N1_2 N1_1 N1_0 0010010 - - - - M1_11 M1_10 M1_9 M1_8 0010011 M1_7 M1_6 M1_5 M1_4 M1_3 M1_2 M1_1 M1_0 The frequency synthesizer consists of a voltage-controlled oscillator (VCO), a crystal oscillator, phase select prescaler, programmable frequency dividers and a phasedetector. The length of the N, M, and A registers are 12, 12 and 6 respectively. The N, M, and A values can be calculated from the formula: f PhD = f XCO f VCO f RF , = = (31 × N + A ) (31 × N + A )/2 M 1≤A<N PhD: Phase detector comparison frequency fXCO: Crystal oscillator frequency fVCO: Voltage controlled oscillator frequency fRF: Input/output RF frequency There are two sets of each of the divide factors (i.e. A0 and A1). Storing the ‘0’ and the ‘1’ frequency in the 0- and the 1 registers respectively, does the 2-FSK. The receive frequency must be stored in the ‘0’ registers. Crystal Oscillator (XCO) Adr D7 D6 D5 D4 D3 D2 D1 D0 0001001 ‘0’ ‘1’ ‘1’ XCOtune4 XCOtune3 XCOtune2 XCOtune1 XCOtune0 The crystal oscillator is a reference for the RF output frequency and the LO frequency in the receiver. It is possible to tune the internal crystal oscillator by switching in internal capacitance using 5 tune bits XCOtune4 – XCOtun0. The benefit of tuning the crystal oscillator is to eliminate the initial tolerance and the tolerance over temperature and aging. By using the crystal tuning feature the noise bandwidth of the receiver can be reduced and a higher sensitivity is achieved. When XCOtune4 – XCOtune0 = 0 no internal capacitors are connected to the crystal pins. When XCOtune4 – XCOtune0 = 1 all of the internal capacitors are connected to the crystal pins. Figure 5 shows the tuning range. September 2005 11 M9999-091905 Micrel, Inc. MICRF600 Tuning range 55.0 1000 45.0 Frequency (MHz) 35.0 25.0 [ppm] 15.0 5.0 -5.0 -15.0 -25.0 -35.0 -45.0 0 4 8 12 16 20 24 28 950 '10' 900 '11' 850 800 32 0 [XCO_tune value] 0,5 1 1,5 2 2,5 Varactor voltage (V) Figure 5. XCO Tuning The typical start up time for the crystal oscillator (default XCO_tune=13) is ~750us. If more capacitance is added (higher XCO_tune value), then the start-up time will be longer. To save current in the crystal oscillator start-up period, the XCO is turned on before any other circuit block. When the XCO has settled, rest of the circuit will be turned on. No programming should be made during this period. The current consumption during the prestart period is approximately 280µA. VCO A6..A0 D7 D6 D5 D4 D3 D2 D1 D0 0000011 ‘1’ ‘1’ ‘0’ VCO_IB2 VCO_IB1 VCO_IB0 VCO_freq1 VCO_freq0 The VCO has no external components. It has three bit to set the bias current and two bit to set the VCO frequency. These five bits are set by the RF frequency, as follows: RF freq. VCO_IB2 VCO_IB1 VCO_IB0 915MHz 0 0 1 1 0 950MHz 0 0 0 1 1 Figure 6. RF Frequency vs. Varactor Voltage and VCO Frequency bit (VDD = 2.25V) Lock Detect D7 D6 D5 D4 D3 D2 D1 D0 ‘1’ ‘0’ ‘0’ ‘0’ RSSI_en LD_en PF_FC1 PF_FC0 A lock detector can be enabled by setting LD_en = 1. When pin LD is high, it indicates that the PLL is in lock. When entering TX, the procedure is first to load the TX word and then turn on the PA stage. During the PA ramp up time, the LD signal may indicate out of lock. It is first when the PA stage is fully on that the LD signal will indicate in “Lock”. During transmission, the Lock Detect signal will have transitions and the user should therefore, ignore the Lock detect signal. Modes of Operation A6..A0 D7 D6 D5 D4 D3 D2 D1 D0 0000000 LNA_by PA2 PA1 PA0 Sync_en Mode1 Mode0 ’1’ VCO_freq1 VCO_freq0 Table 7. VCO Bit Setting The bias bit will optimize the phase noise, and the frequency bit will control a capacitor bank in the VCO. The tuning range the RF frequency versus varactor voltage is dependent on the VCO frequency setting, and can be shown in Figure 6. September 2005 A6..A0 0000001 12 Mode1 Mode0 State 0 0 Power down Keeps register configuration Comments 0 1 Standby Only crystal oscillator running 1 0 Receive Full receive 1 1 Transmit Full transmit ex PA state M9999-091905 Micrel, Inc. MICRF600 Transceiver Sync/Non-Synchronous Mode A6..A0 0000000 0000110 0000111 D7 D6 LNA_by PA2 ‘0’ BitRate_clkS1 BitRate_clkS0 D5 PA1 ‘0’ RefClk_K5 Sync_en State Comments 0 Rx: Bit synchronization off Transparent reception of data 0 Tx: DataClk pin off Transparent transmission of data 1 Rx: Bit synchronization on Bit-clock is generated by transceiver 1 Tx: DataClk pin on Bit-clock is generated by transceiver D4 D3 D2 D1 D0 PA0 Sync_en Mode1 Mode0 ’1’ ‘0’ BitSync_clkS2 BitSync_clkS1 BitSync_clkS0 BitRate_clkS2 RefClk_K4 RefClk_K3 RefClk_K2 RefClk_K1 RefClk_K0 When Sync_en = 1, it will enable the bit synchronizer in receive mode. The bit synchronizer clock needs to be programmed, see chapter Bit synchronizer. The synchronized clock will be set out on pit DataClk. In transmit mode, when Sync_en = 1, the clock signal on pin DataClk is a programmed bit rate clock. Now the transceiver controls the actual data rate. The data to be transmitted will be sampled on rising edge of DataClk. The micro controller can therefore use the negative edge to change the data to be transmitted. The clock used for this purpose, BitRate-clock, is programmed in the same way as the modulator clock and the bit synchronizer clock: fBITRATE_CL K = MICRF600 will present data on rising edge and the “USER” sample data on falling edge in receive mode. DATAIXO DATACLK Figure 7. Data Interface in Receive Mode The User presents data on falling edge and MICRF600 samples on rising edge in transmit mode. DATAIXO DATACLK f XCO Refclk_K × 2 (7-BITRATE_c lkS) where: fBITRATE_CLK: The clock frequency used to control the bit rate, should be equal to the bit rate (bit rate of 20 kbit/sec requires a clock frequency of 20kHz) fXCO: Crystal oscillator frequency Refclk_K: 6 bit divider, values between 1 and 63 BitRate_clkS: Bit rate setting, values between 0 and 6 Data Interface The MICRF600 interface can be divided in to two separate interfaces, a “programming interface” and a “Data interface”. The “programming interface” has a three wire serial programmable interface and is described in chapter Programming. The “data interface” can be programmed to sync-/nonsynchronous mode. In synchronous mode the MICRF600 is defined as “Master” and provides a data clock that allows users to utilize low cost micro controller reference frequency. September 2005 The data interface is defined in such a way that all user actions should take place on falling edge and is illustrated Figure 7 and 8. The two figures illustrate the relationship between DATACLK and DATAIXO in receive mode and transmit mode. Figure 8. Data Interface in Transmit Mode Receiver The receiver is a zero intermediate frequency (IF) type in order to make channel filtering possible with low-power integrated low-pass filters. The receiver consists of a low noise amplifier (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 lowpass filter from strong adjacent channel signals and finally a limiter. The main channel filter is a switched-capacitor implementation of a six-pole elliptic lowpass filter. The elliptic filter minimizes the total capacitance required for a given selectivity and dynamic range. The cut-off frequency of the Sallen-Key RC filter can be programmed to four different frequencies: 100kHz, 150kHz, 230kHz and 340kHz. The demodulator demodulates the I and Q channel outputs and produces a digital data output. If detects the relative phase of the I and Q channel signal. If the I channel signal lags the Q channel, the FSK tone frequency lies above the LO frequency (data ‘1’). If the I channel leads the Q channel, the FSK tone lies below the LO frequency (data ‘0’). The output of the receiver is available on the DataIXO pin. A RSSI circuit (receive signal strength indicator) indicates the received signal level. 13 M9999-091905 Micrel, Inc. MICRF600 fCUT: Filter cutoff frequency Front End A6..A0 D7 D6 D5 D4 D3 D2 D1 D0 0000000 LNA_by PA2 PA1 PA0 Sync_en Mode1 Mode0 ’1’ fXCO: Crystal oscillator frequency A low noise amplifier in RF receivers is used to boost the incoming signal prior to the frequency conversion process. This is important in order to prevent mixer noise from dominating the overall front-end noise performance. The LNA is a two-stage amplifier and has a nominal gain of approximately 23dB at 900MHz. The front end has a gain of about 33dB to 35dB. The gain varies by 1-1.5dB over a 2.0V to 2.5V variation in power supply. The LNA can be bypassed by setting bit LNA_by to ‘1’. This can be useful for very strong input signal levels. The front-end gain with the LNA bypassed is about 9-10dB. The mixers have a gain of about 10dB at 900MHz. ScCLK: Switched capacitor filter clock, bits ScClk5-0 st 1 order RC lowpass filters are connected to the output of the SC filter to filter the clock frequency. The lowest cutoff frequency in the pre- and the main channel filter must be set so that the received signal is passed with no attenuation, that is frequency deviation plus modulation. If there are any frequency offset between the transmitter and the receiver, this must also be taken into consideration. A formula for the receiver bandwidth can be summarized as follows: fBW = + fOFFSET + fDEV + Baudrate / 2 where Sallen-Key Filters A6..A0 D7 D6 D5 D4 D3 D2 D1 D0 0000001 ‘1’ ‘0’ ‘0’ ‘0’ RSSI_en LD_en PF_FC1 PF_FC0 Each channel includes a pre-amplifier and a prefilter, which is a three-pole Sallen-Key lowpass filter. It protects the following switched-capacitor filter from strong adjacent channel signals, and it also works as an anti-aliasing filter. The preamplifier has a gain of 22.23dB. The maximum output voltage swing is about 1.4Vpp for a 2.25V power supply. In addition, the IF amplifier also performs offset cancellation. Gain varies by less than 0.5dB over a 2.0 – 2.5V variation in power supply. The third order Sallen-Key lowpass filter is programmable to four different cut-off frequencies according to the table below: PF_FC1 PF_FC0 Cut-off Freq. (kHz) 0 0 100 0 1 150 1 0 230 1 1 340 fBW: Needed receiver bandwidth, fcut above should not be smaller than fBW (Hz) foffset: Total frequency offset between receiver and transmitter (Hz) fDEV: Single-sided frequency deviation Baudrate: The baud rate given is bit/sec RSSI A6..A0 D7 D6 D5 D4 D3 D2 D1 D0 0000001 ‘1’ ‘0’ ‘0’ ‘0’ RSSI_en LD_en PF_FC1 PF_FC0 RSSI 2,5 2 1,5 1 Switched Capacitor Filter A6..A0 D7 D6 D5 D4 D3 D2 D1 D0 0001000 ‘1’ ‘1’ ScClk5 ScClk4 ScClk3 ScClk2 ScClk1 ScClk0 0,5 0 -110 The main channel filter is a switched-capacitor implementation of a six-pole elliptic low pass filter. The elliptic filter minimized the total capacitance required for a given selectivity and dynamic range. The cut-off frequency of the switched-capacitor filter is adjustable by changing the clock frequency. The clock frequency is designed to be 20 times the cut-off frequency. The clock frequency is derived from the reference crystal oscillator. A programmable 6-bit divider divides the frequency of the crystal oscillator. The cut-off frequency of the filter is given by: fCUT = fXCO 40 ⋅ ScClk September 2005 -100 -90 -80 -70 Pin (dBm) -60 -50 -40 Figure 9. RSSI Voltage A Typical plot of the RSSI voltage as function of input power is shown in Figure 9. The RSSI has a dynamic range of about 50dB from about -110dBm to -60dBm input power. The RSSI can be used as a signal presence indicator. When a RF signal is received, the RSSI output increases. This could be used to wake up circuitry that is normally in a sleep mode configuration to conserve battery life. 14 M9999-091905 Micrel, Inc. MICRF600 Another application for which the RSSI could be used is to determine if transmit power can be reduced in a system. If the RSSI detects a strong signal, it could tell the transmitter to reduce the transmit power to reduce current consumption. FEE A6..A0 D7 D6 D5 D4 D3 D2 D1 D0 0010101 - - - - FEEC_3 FEEC_2 FEEC_1 FEEC_0 0010110 FEE_7 FEE_6 FEE_5 FEE_4 FEE_3 FEE_2 FEE_1 FEE_0 The Frequency Error Estimator (FEE) uses information from the demodulator to calculate the frequency offset between the receive frequency and the transmitter frequency. The output of the FEE can be used to tune the XCO frequency, both for production calibration and for compensation for crystal temperature drift and aging. The input to the FEE circuit are the up and down pulses from the demodulator. Every time a ‘1’ is updated, an UPpulse is coming out of the demodulator and the same with the DN-pulse every time the ‘0’ is updated. The expected no. of pulses for every received symbol is 2 times the modulation index (∆). The FEE can operate in three different modes; counting only UP-pulses, only DN-pulses or counting UP+DN pulses. The no. of received symbols to be counted is either 8, 16, 32 or 64. This is set by the FEEC_0…FEEC_3 control bit, as follows: FEEC_1 FEEC_0 0 0 Off 0 1 Counting UP pulses 1 0 Counting DN pulses 1 1 Counting UP and DN pulses. UP increments the counter, DN decrements it. FEEC_3 FEEC_2 0 0 8 0 1 16 1 0 32 1 1 65 The result of the measurement is the FEE value, this can be read from register with address 0010110b. Negative values are stored as a binary no between 0000000 and 1111111. To calculate the negative value, a two’s complement of this value must be performed. Only FEE modes where DN-pulses are counted (10 and 11) will give a negative value. When the FEE value has been read, the frequency offset can be calculated as follows: Mode UP: Foffset = R/(2P)x(FEE-∆Fp) Mode DN: Foffset = R/(2P)x(FEE+∆Fp) Mode UP+DN: Foffset = R/(4P)x(FEE) where FEE is the value stored in the FEE register, (Fp is the single sided frequency deviation, P is the no. of symbols/data bit counted and R is the symbol/data rate. A positive Foffset means that the received signal has a higher frequency than the receiver frequency. To compensate for this, the receivers XCO frequency should be increased. It is recommended to use Mode UP+DN for two reasons, you do not need to know the actual frequency deviation and this mode gives the best accuracy. FEE Mode No. of symbols used for the measurement Table 8. FEEC Control Bit Bit Synchronizer A6..A0 D7 D6 D5 D4 D3 D2 D1 D0 0000110 ‘0’ ‘0’ ‘0’ BitSync_clkS2 BitSync_clkS1 BitSync_clkS0 BitRate_clkS2 0000111 BitRate_clkS1 BitRate_clkS0 RefClk_K5 RefClk_K4 RefClk_K3 RefClk_K2 RefClk_K1 RefClk_K0 September 2005 15 M9999-091905 Micrel, Inc. MICRF600 A bit synchronizer can be enabled in receive mode by selecting the synchronous mode (Sync_en=1). The DataClk pin will output a clock with twice the frequency of the bit rate (a bit rate of 20 kbit/sec gives a DataClk of 20 kHz). A received symbol/bit on DataIXO will be output on rising edge of DataClk. The micro controller should therefore, sample the symbol/bit on falling edge of DataClk. The bit synchronizer uses a clock that needs to be programmed according to the bit rate. The clock frequency should be 16 times the actual bit rate (a bit rate of 20 kbit/sec needs a bit synchronizer clock with frequency of 320 kHz). The clock frequency is set by the following formula: fBITSYNC_CLK = fXCO Refclk_K × 2 (7-BITSYNC_clkS) where fBITSYNC_CLK: The bit synchronizer clock frequency (16 times higher than the bit rate) fXCO: Crystal oscillator frequency Refclk_K: 6 bit divider, values between 1 and 63 BitSync_clkS: Bit synchronizer setting, values between 0 and 7 Refclk_K is also used to derive the modulator clock and the bit rate clock. At the beginning of a received data package, the bit synchronizer clock frequency is not synchronized to the bit rate. When these two are maximum offset to each other, it takes 22 bit/symbols before synchronization is achieved. and A values is given in chapter Frequency synthesizer. The divider values stored in the M0-, N0-, and A0registers will be used when transmitting a ‘0’ and the M1-, N1-, and A1-registers will be used to transmit a ‘1’. The difference between the two carrier frequencies corresponds to the double-sided frequency deviation. The data to be transmitted shall be applied to pin DataIXO (see chapter Transceiver sync-/non-synchronous mode on how to use the pin DataClk). The DataIXO pin is set as input in transmit mode and output in receive mode. Using the XCO-tune Bits The module has a built-in mechanism for tuning the frequency of the crystal oscillator and is often used in combination with the Frequency Error Estimator (FEE). The XCO tuning is designed to eliminate or reduce initial frequency tolerance of the crystal and/or the frequency stability over temperature. A procedure for using the XCO tuning feature in combination with the FEE is given below. The MICRF600 measures the frequency offset between the receivers LO frequency and the frequency of the transmitter. The receiver XCO frequency can be tuned until the receiver and transmitter frequencies are equal. A procedure like this can be called during production (storing the calibrated XCO_tune value), at regular intervals or implemented in the communication protocol when the frequency has changed. The MICRF600 development system can test this feature. Example: In FEE, count up+down pulses, counting 8 bits: A perfect case ==> FEE = 0 Transmitter If FEE > 0: LO is too low, increase LO by decreasing XCO_tune value Power Amplifier v.v. for FEE < 0 A6..A0 D7 D6 D5 D4 D3 D2 D1 D0 0000000 LNA_by PA2 PA1 PA0 Sync_en Mode1 Mode0 ’1’ 0000001 ‘1’ ‘0’ ‘0’ ‘0’ RSSI_en LD_en PF_FC1 PF_FC0 The maximum output power is approximately 10dBm for a 50Ω load. The output power is programmable in seven steps, with approximately 3dB between each step. Bits PA2 – PA0, control this. PA2 – PA0 = 1 give the maximum output power. The power amplifier can be turned off by setting PA2 – PA0 = 0. For all other combinations the PA is on and has maximum power when PA2 – PA0 = 1. FEE field holds a number in the range -128, … , 127. However, it keeps counting above/below the range, which is: If FEE = -128 and still counting dwn-pulses: 1) =>-129 = +127 2) 126 3) 125 To avoid this situation, always make sure max count is between limits. Frequency Modulation FSK modulation is applied by switching between two sets of dividers (M,N,A). The formula for calculating the M, N September 2005 16 M9999-091905 Micrel, Inc. MICRF600 Application Circuit Illustration Assembling the MICRF600 Recommended Reflow Temperature Profile When the MICRF600 module is being automatically assembled to a PCB, care must be taken not to expose the module for temperature above the maximum specified. Figure 12 shows the recommended reflow temperature profile. LDO MCU MICRF600 4004 Figure 10. Circuit illustration of MICRF600, LDO and MCU Figure 10 shows a typical set-up with the MICRF600, a Low-Drop-Out voltage regulator (LDO) and a microcontroller (MCU). When the MICRF600 and the MCU runs on the same power supply (min 2.0, max. 2.5V), the IO can be connected directly to the MCU. If the MCU needs a higher VDD than the maximum specified VDD of the MICRF600 (2.5V), voltage dividers need to be added on the IO lines not to override the max. input voltage. Figure 11 shows a recommended voltage divider circuit for a MCU running at 3.0V and the MICRF600 at 2.5V. MICRF6xx MCU 3k3 CS CS 18k 3k3 SCLK 3k3 IO IO 18k 15k DATAIXO DATAIXO DATACLK DATACLK RSSI Shock/Vibration during Reflow The module has several components inside which are assembled in a reflow process. These components may reflow again when the module is assembled onto a PCB. It is therefore, important that the module is not subjected to any mechanical shock or vibration during this process. SCLK 18k LD Figure 12. Recommended Reflow Temperature Reflow Handassembling the MICRF600 It is recommended that solder paste also be used during hand assembling of the module. Because of the module ground pad on the bottom side, the module will be assembled most efficiently if the heat is being subjected to the bottom side of the PCB. The heat will be transferred trough the PCB due the ground vias under the module (see Layout Considerations). In addition, it is recommended that a solder tip be used on the signal and power pads. This will ensure that the solder points are properly melted. LD RSSI Figure 11. How to connect MCU600 (2.5V) and MCU (3.0V) September 2005 17 M9999-091905 Micrel, Inc. Layout Recommended Land Pattern Figure 12 shows a recommended land pattern that facilitates both automatic and hand assembling. MICRF600 Layout Considerations Except for the antenna input/output signal, only digital and low frequency signals need to interface with the module. There is therefore no need of years of RF expertise to do a successful layout, as long as the following few points are being followed: Figure 13. Recommended Land Pattern September 2005 18 • Proper ground is needed. If the PCB is 2-layer, the bottom layer should be kept only for ground. Avoid signal traces that split the ground plane. For a 4layer PCB, it is recommended the second layer only for ground be kept. • A ground via should be placed close to all the ground pins. The bottom ground pad should be penetrated with 4-16 ground vias. • The antenna has a impedance of ~50Ω. The antenna trace should be kept to 50Ω to avoid signal reflection and loss of performance. Any transmission line calculator can be used to find the needed trace width given a board build up. Example: A trace width of 44 mil (1.12 mm) gives 50 impedance on a FR4 board (dielectric cons=4.4) with copper thickness of 35µm and height (layer 1-layer 2 spacing) of 0.61 mm. M9999-091905 Micrel, Inc. MICRF600 10 11 12 13 14 15 16 xxxx 10.68mm 9 11.5 ± 0.05mm 8 7 6 5 4 MICRF600 1 2 3 Package Dimensions 3.0 ± 0.2mm 0.71 ± 0.02mm 14.1 ± 0.1mm 13.22mm Figure 14. Package Dimensions Tape Dimensions Figure 15. Tape Dimensions MICREL, INC. 2180 FORTUNE DRIVE SAN JOSE, CA 95131 USA TEL +1 (408) 944-0800 FAX +1 (408) 474-1000 WEB http:/www.micrel.com The information furnished by Micrel in this data sheet is believed to be accurate and reliable. However, no responsibility is assumed by Micrel for its use. Micrel reserves the right to change circuitry and specifications at any time without notification to the customer. Micrel Products are not designed or authorized for use as components in life support appliances, devices or systems where malfunction of a product can reasonably be expected to result in personal injury. Life support devices or systems are devices or systems that (a) are intended for surgical implant into the body or (b) support or sustain life, and whose failure to perform can be reasonably expected to result in a significant injury to the user. A Purchaser’s use or sale of Micrel Products for use in life support appliances, devices or systems is a Purchaser’s own risk and Purchaser agrees to fully indemnify Micrel for any damages resulting from such use or sale. © 2005 Micrel, Incorporated. September 2005 19 M9999-091905