RFM42B/43B RFM42B/43B ISM T RANSMITTER V1.0 Features Frequency range 433/868/915MHz ISM bands Output Power Range +1 to +20dBm (RFM42B) –8 to +13dBm (RFM43B) Low Power Consumption RFM42B 85 mA @ +20 dBm RFM43B 30 mA @ +13 dBm Data Rate = 0.123 to 256 kbps FSK, GFSK, and OOK modulation Power Supply = 1.8 to 3.6 V Ultra low power shutdown mode Wake-up timer Integrated 32 kHz RC or 32 kHz XTAL Integrated voltage regulators Configurable packet handler TX 64 byte FIFO Low battery detector Temperature sensor and 8-bit ADC –40 to +85 °C temperature range Integrated voltage regulators Frequency hopping capability On-chip crystal tuning 14-PIN DIP & 16-PIN SMD package Low cost Power-on-reset (POR) Remote meter reading Remote keyless entry Home automation Industrial control Sensor networks Health monitors RFM42B/43B Applications Remote control Home security & alarm Telemetry Personal data logging Toy control Wireless PC peripherals Description HopeRF's RFM42B/43B are highly integrated, low cost,433/868/915MHZ wireless ISM transmitters module. The RFM42B/43B offers advanced radio features including adjustable power output levels of –8 to +13dBm on the RFM43B and +1 to +20dBm on the RFM42B.Power adjustments are made in 3dB steps.The RFM42B/43B's high level of integration offers reduced BOM cost while simplifying the overall system design. The RFM42B’s Industry leading +20dBm output power ensures extended range and improved link performance. Additional system features such as an automatic wake-up timer, low battery detector, 64 byte TX FIFO, and automatic packet handling reduce overall current consumption and allow the use of lower-cost system MCUs. An integrated temperature sensor, general purpose ADC, power-on-reset (POR), and GPIOs further reduce overall system cost and size. The direct digital transmit modulation and automatic PA power ramping ensure precise transmit modulation and reduced spectral spreading ensuring compliance with global regulations including FCC,ETSI regulations. An easy-to-use calculator is provided to quickly configure the radio settings, simplifying customer's system design and reducing time to market. Tel: +86-755-82973805 1 Fax: +86-755-82973550 E-mail: [email protected] http://www.hoperf.com RFM42B/43B TABLE O F C ONTENTS Section Page 1. Electrical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4 2. Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10 2.1. Operating Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10 3. Controller Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 3.1. Serial Peripheral Interface (SPI) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 3.2. Operating Mode Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 3.3. Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 3.4. System Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 3.5. Frequency Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18 4. Modulation Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 4.1. Modulation Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23 4.2. Modulation Data Source . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 5. Internal Functional Blocks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 5.1. Synthesizer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27 5.2. Power Amplifier . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 5.3. Crystal Oscillator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29 5.4. Regulators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29 6. Data Handling and Packet Handler . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30 6.1. TX FIFO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30 6.2. Packet Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31 6.3. Packet Handler TX Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31 6.4. Data Whitening, Manchester Encoding, and CRC . . . . . . . . . . . . . . . . . . . . . . . . . . 33 6.5. Synchronization Word Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 6.6. TX Retransmission and Auto TX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 7. Auxiliary Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35 7.1. Smart Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35 7.2. Microcontroller Clock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .36 7.3. General Purpose ADC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 7.4. Temperature Sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38 7.5. Low Battery Detector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .40 7.6. Wake-Up Timer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 7.7. GPIO Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 8. Reference Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 9. Application Notes and Reference Designs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 10. Pin Descriptions: RFM42B/43B . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 Tel: +86-755-82973805 Fax: +86-755-82973550 E-mail: [email protected] http://www.hoperf.com 2 RFM42B/43B 11. Mechanical Dimension: RFM42B/ 43B . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 12. Ordering Information: RFM42B/43B. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 Contact Information: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51 3 Tel: +86-755-82973805 Fax: +86-755-82973550 E-mail: [email protected] http://www.hoperf.com RFM42B/43B 1. Electrical Specifications Table 1. DC Characteristics Parameter Symbol Supply Voltage Range VDD Power Saving Modes IShutdown TUNE Mode Current TX Mode Current —RFM42B TX Mode Current —RFM43B Min Typ 1.8 3.0 3.6 V RC Oscillator, Main Digital Regulator, and Low Power Digital Regulator OFF — 15 50 nA IStandby Low Power Digital Regulator ON (Register values retained) and Main Digital Regulator, and RC Oscillator OFF — 450 800 nA ISleep RC Oscillator and Low Power Digital Regulator ON (Register values retained) and Main Digital Regulator OFF — 1 — µA ISensor-LBD Main Digital Regulator and Low Battery Detector ON, Crystal Oscillator and all other blocks OFF — 1 — µA ISensor-TS Main Digital Regulator and Temperature Sensor ON, Crystal Oscillator and all other blocks OFF — 1 — µA IReady Crystal Oscillator and Main Digital Regulator ON, all other blocks OFF. Crystal Oscillator buffer disabled — 800 — µA ITune Synthesizer and regulators enabled — 8.5 — mA ITX_+20 txpow[2:0] = 111 (+20 dBm) — 85 — mA ITX_+13 txpow[2:0] = 111 (+13 dBm) — 30 — mA ITX_+1 txpow[2:0] = 011 (+1 dBm) — 18 — mA Tel: +86-755-82973805 Conditions Fax: +86-755-82973550 Max Units E-mail: [email protected] http://www.hoperf.com 4 RFM42B/43B Table 2. Synthesizer AC Electrical Characteristics Parameter Synthesizer Frequency Range—RFM42B/43B Synthesizer Frequency Resolution Symbol Max Units 868MHz band 413 848 453 888 MHz MHz 915MHz band 901 929 MHz FRES-LB 433MHz Band — 156.25 — Hz FRES-HB 868/915MHz Band — 312.5 — Hz FSYN Conditions Min 433MHz band Typ fREF_LV When using external reference signal driving XOUT pin, instead of using crystal. Measured peak-to-peak (VPP) 0.7 — 1.6 V Synthesizer Settling Time tLOCK Measured from exiting Ready mode with XOSC running to any frequency. Including VCO calibration. — 200 — µs Residual FM FRMS Integrated over 250 kHz bandwidth (500 Hz lower bound of integration) — 2 4 kHzRMS Phase Noise L(fM) F = 10 kHz — –80 — dBc/Hz F = 100 kHz — –90 — dBc/Hz F = 1 MHz — –115 — dBc/Hz F = 10 MHz — –130 — dBc/Hz Reference Frequency Input Level Tel: +86-755-82973805 5 Fax: +86-755-82973550 E-mail: [email protected] http://www.hoperf.com RFM42B/43B Table 3. Transmitter AC Electrical Characteristics Parameter TX Frequency Range—RFM42B/43B Symbol FTX Conditions Min 433MHz band Typ Max Units 868MHz band 413 848 453 888 MHz MHz 915MHz band 901 929 MHz FSK Data Rate DRFSK 0.123 — 256 kbps OOK Data Rate DROOK 0.123 — 40 kbps Modulation Deviation Δf1 868/915MHz band ±0.625 ±320 kHz Δf2 433MHz band ±0.625 ±160 kHz ΔfRES — 0.625 — kHz Output Power Range —RFM42B PTX +1 — +20 dBm Output Power Range—RFM43B PTX –8 — +13 dBm Modulation Deviation Resolution TX RF Output Steps PRF_OUT controlled by txpow[2:0] — 3 — dB TX RF Output Level Variation vs. Temperature PRF_TEMP –40 to +85 C — 2 — dB TX RF Output Level Variation vs. Frequency PRF_FREQ Measured across any one frequency band — 1 — dB B*T Gaussian Filtering Bandwith Time Product — 0.5 — POB-TX1 POUT = 13 dBm, Frequencies <1 GHz — — –54 dBm POB-TX2 1–12.75 GHz, excluding harmonics — — –54 dBm Transmit Modulation Filtering Spurious Emissions Tel: +86-755-82973805 Fax: +86-755-82973550 E-mail: [email protected] http://www.hoperf.com 6 RFM42B/43B Table 4. Auxiliary Block Specifications Parameter Symbol Conditions Min Typ Max Units Temperature Sensor Accuracy TSA After calibrated via sensor offset register tvoffs[7:0] — 0.5 — °C Temperature Sensor Sensitivity TSS — 5 — mV/°C Low Battery Detector Resolution LBDRES — 50 — mV Low Battery Detector Conversion Time LBDCT — 250 — µs Microcontroller Clock Output Frequency FMC 32.768K — 30M Hz Configurable to 30 MHz, 15 MHz, 10 MHz, 4 MHz, 3 MHz, 2 MHz, 1 MHz, or 32.768 kHz General Purpose ADC Resolution ADCENB — 8 — bit General Purpose ADC Bit Resolution ADCRES — 4 — mV/bit Temp Sensor & General Purpose ADC Conversion Time ADCCT — 305 — µs t30M — 600 — µs 30MRES — 97 — fF t32k — 6 — sec 32 kHz XTAL Accuracy using 32 kHz XTAL 32KRES — 100 — ppm 32 kHz Accuracy using Internal RC Oscillator 32KRCRES — 2500 — ppm POR Reset Time tPOR — 16 — ms Software Reset Time tsoft — 100 — µs 30 MHz XTAL Start-Up time 30 MHz XTAL Cap Resolution 32 kHz XTAL Start-Up Time 7 Tel: +86-755-82973805 Fax: +86-755-82973550 E-mail: [email protected] http://www.hoperf.com RFM42B/43B Table 5. Digital IO Specifications (SDO, SDI, SCLK, nSEL, and nIRQ) Symbol Conditions Min Typ Max Units Rise Time TRISE 0.1 x VDD to 0.9 x VDD, CL= 5 pF — — 8 ns Fall Time TFALL 0.9 x VDD to 0.1 x VDD, CL= 5 pF — — 8 ns Parameter Input Capacitance CIN — — 1 pF Logic High Level Input Voltage VIH VDD – 0.6 — — V Logic Low Level Input Voltage VIL — 0.6 V Input Current IIN 0<VIN< VDD –100 — 100 nA Logic High Level Output Voltage VOH IOH<1 mA source, VDD=1.8 V VDD – 0.6 — — V Logic Low Level Output Voltage VOL IOL<1 mA sink, VDD=1.8 V — — 0.6 V Table 6. GPIO Specifications (GPIO_0, GPIO_1, and GPIO_2) Symbol Conditions Min Typ Max Units Rise Time TRISE 0.1 x VDD to 0.9 x VDD, CL= 10 pF, DRV<1:0>=HH — — 8 ns Fall Time TFALL 0.9 x VDD to 0.1 x VDD, CL= 10 pF, DRV<1:0>=HH — — 8 ns 1 pF Parameter Input Capacitance CIN — — Logic High Level Input Voltage VIH VDD – 0.6 — Logic Low Level Input Voltage VIL — — 0.6 V Input Current IIN 0<VIN< VDD –100 — 100 nA Input Current If Pullup is Activated IINP VIL=0 V 5 — 25 µA IOmaxLL DRV<1:0>=LL 0.1 0.5 0.8 mA IOmaxLH DRV<1:0>=LH 0.9 2.3 3.5 mA IOmaxHL DRV<1:0>=HL 1.5 3.1 4.8 mA IOmaxHH DRV<1:0>=HH 1.8 3.6 5.4 mA Logic High Level Output Voltage VOH IOH< IOmax source, VDD=1.8 V VDD – 0.6 — — V Logic Low Level Output Voltage VOL IOL< IOmax sink, VDD=1.8 V — — 0.6 V Maximum Output Current Tel: +86-755-82973805 Fax: +86-755-82973550 V E-mail: [email protected] http://www.hoperf.com 8 RFM42B/43B Table 7. Absolute Maximum Ratings Parameter Value Unit VDD to GND –0.3, +3.6 V Instantaneous VRF-peak to GND on TX Output Pin –0.3, +8.0 V Sustained VRF-peak to GND on TX Output Pin –0.3, +6.5 V Voltage on Digital Control Inputs –0.3, VDD + 0.3 V Voltage on Analog Inputs –0.3, VDD + 0.3 V Operating Temperature Range (special crystal is used on the module) T S –40 to +85 C Operating Temperature Range (Normal crystal is used on the module) TN –20 to +60 C 30 C/W –55 to +125 C Thermal Impedance JA Storage Temperature Range TSTG Note: Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only and functional operation of the device at or beyond these ratings in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Power Amplifier may be damaged if switched on without proper load or termination connected. TX matching network design will influence TX VRF-peak on TX output pin. Caution: ESD sensitive device. 9 Tel: +86-755-82973805 Fax: +86-755-82973550 E-mail: [email protected] http://www.hoperf.com RFM42B/43B 2. Functional Description HopeRF's RFM42B/43B are highly integrated,low cost,433/868/915MHz wireless ISM transmitters module . The wide operating voltage range of 1.8–3.6V and low current consumption makes the RFM42B/43B an ideal solution for battery powered applications. The RF carrier is generated by an integrated VCO and Fractional-N PLL synthesizer. The synthesizer is designed to support configurable data rates, output frequency, frequency deviation, and Gaussian filtering at 433MHz, 868MHz, 915MHz band. The transmit FSK data is modulated directly into the data stream and can be shaped by a Gaussian low-pass filter to reduce unwanted spectral content. The RFM42B’s PA output power can be configured between +1 and +20dBm in 3dB steps, while the RFM43B's PA output power can be configured between –8 and +13 dBm in 3dB steps. The PA incorporates automatic ramp-up and ramp-down control to reduce unwanted spectral spreading. The RFM42B/43B is designed to work with a microcontroller to create a very low cost system. Voltage regulators are integrated on-chip which allows for a wide operating supply voltage range from +1.8 to +3.6V. A standard 4-pin SPI bus is used to communicate with an external microcontroller. Three configurable general purpose I/Os are available. A complete list of the available GPIO functions is available in “ RFM42B/43B Register Descriptions.” 2.1. Operating Modes The RFM42B/43B provides several operating modes which can be used to optimize the power consumption for a given application. Table8 summarizes the operating modes of the RFM42B/43B. In general, any given operating mode may be classified as an active mode or a power saving mode. The table indicates which block(s) are enabled (active) in each corresponding mode. With the exception of the SHUTDOWN mode, all can be dynamically selected by sending the appropriate commands over the SPI. An “X” in any cell means that, in the given mode of operation, that block can be independently programmed to be either ON or OFF, without noticeably impacting the current consumption. The SPI circuit block includes the SPI interface hardware and the device register space. The 32 kHz OSC block includes the 32.768 kHz RC oscillator or 32.768 kHz crystal oscillator and wake-up timer. AUX (Auxiliary Blocks) includes the temperature sensor, general purpose ADC, and low-battery detector. Table 8. Operating Modes Mode Name SHUTDOWN STANDBY SLEEP SENSOR READY TUNING TRANSMIT Circuit Blocks 32 kHz OSC AUX Digital LDO SPI OFF (Register contents lost) ON (Register contents retained) OFF OFF ON ON ON ON ON ON OFF ON X X X X PLL PA IVDD OFF 30 MHz XTAL OFF OFF OFF 15 nA OFF X ON X X X OFF OFF OFF ON ON ON OFF OFF OFF OFF ON ON OFF OFF OFF OFF OFF ON 450 nA 1 µA 1 µA 800 µA 8.5 mA 30 mA* *Note: Using RFM43B at +13dBm usin g recommended reference design. 10 Tel: +86-755-82973805 Fax: +86-755-82973550 E-mail: [email protected] http://www.hoperf.com RFM42B/43B 3. Controller Interface 3.1. Serial Peripheral Interface (SPI) The RFM42B/43B communicates with the host MCU over a standard 3-wire SPI interface: SCLK, SDI, and nSEL. The host MCU can read data from the device on the SDO output pin. A SPI transaction is a 16-bit sequence which consists of a Read-Write (R/W) select bit, followed by a 7-bit address field (ADDR), and an 8-bit data field (DATA) as demonstrated in Figure 1. The 7-bit address field is used to select one of the 128, 8-bit control registers. The R/W select bit determines whether the SPI transaction is a read or write transaction. If R/W = 1 it signifies a WRITE transaction, while R/W = 0 signifies a READ transaction. The contents (ADDR or DATA) are latched into the RFM42B/43B every eight clock cycles. The timing parameters for the SPI interface are shown in Table 9. The SCLK rate is flexible with a maximum rate of 10 MHz. Data Address MSB SDI LSB RW A6 A5 A4 A3 A2 A1 A0 D7 D6 D5 D4 D3 D2 D1 D0 xx xx RW A7 SCLK nSEL Figure 1. SPI Timing Table 9. Serial Interface Timing Parameters Symbol Parameter Min (nsec) tCH Clock high time 40 tCL Clock low time 40 tDS Data setup time 20 tDH Data hold time 20 tDD Output data delay time 20 tEN Output enable time 20 tDE Output disable time 50 tSS Select setup time 20 tSH Select hold time 50 tSW Select high period 80 Diagram SCLK tSS tCL tCH tDS tDH tDD tSH tDE SDI SDO tEN tSW nSEL To read back data from the RFM42B /43B, the R/W bit must be set to 0 followed by the 7-bit address of the register from which to read. The 8 bit DATA field following the 7-bit ADDR field is ignored n the SDI pin when R/W = 0. The next eight negative edge transitions of the SCLK signal will clock out the contents of the selected register. The data read from the selected register will be available on the SDO output pin. The READ function is shown in Figure 2. After the READ function is completed the SDO pin will remain at either a logic 1 or logic 0 state depending on the last data bit clocked out (D0). When nSEL goes high the SDO output pin will be pulled high by internal pullup. Tel: +86-755-82973805 Fax: +86-755-82973550 E-mail: [email protected] http://www.hoperf.com 11 RFM42B/43B First Bit SDI RW =0 Last Bit D7 =X A6 A5 A4 A3 A2 A1 A0 D6 =X D5 =X D4 =X D3 =X D2 =X D1 =X D0 =X SCLK First Bit SDO Last Bit D7 D6 D5 D4 D3 D2 D1 D0 nSEL Figure 2. SPI Timing—READ Mode The SPI interface contains a burst read/write mode which allows for reading/writing sequential registers without having to re-send the SPI address. When the nSEL bit is held low while continuing to send SCLK pulses, the SPI interface will automatically increment the ADDR and read from/write to the next address. An example burst write transaction is illustrated in Figure 3 and a burst read in Figure 4. As long as nSEL is held low, input data will be latched into the RFM42B/43B every eight SCLK cycles. First Bit RW =1 SDI Last Bit A6 A5 A4 A3 A2 A1 A0 D7 =X D6 =X D5 =X D4 =X D3 =X D2 =X D1 =X D0 =X D7 =X D6 =X D5 =X D4 =X D3 =X D2 =X D1 =X D0 =X SCLK nSEL Figure 3. SPI Timing—Burst Write Mode First Bit SDI RW =0 Last Bit A6 A5 A4 A3 A2 A1 A0 D7 =X D6 =X D5 =X D4 =X D3 =X D2 =X D1 =X D0 =X SCLK First Bit SDO D7 D6 D5 D4 D3 D2 D1 D0 D7 D6 D5 D4 D3 D2 D1 D0 nSEL Figure 4. SPI Timing—Burst Read Mode Tel: +86-755-82973805 12 Fax: +86-755-82973550 E-mail: [email protected] http://www.hoperf.com RFM42B/43B 3.2. Operating Mode Control There are three primary states in the RFM42B/43B radio state machine: SHUTDOWN, IDLE, and TX (see Figure 5). The SHUTDOWN state completely shuts down the radio to minimize current consumption. There are five different configurations/options for the IDLE state which can be selected to optimize the chip to the applications needs. "Register 07h. Operating Mode and Function Control 1" controls which operating mode/state is selected with the exception of SHUTDOWN which is controlled by SDN pin. The TX state may be reached automatically from any of the IDLE states by setting the txon bit in "Register 07h. Operating Mode and Function Control 1." Table 10 shows each of the operating modes with the time required to reach TX mode as well as the current consumption of each mode. The RFM42B/43B includes a low-power digital regulated supply (LPLDO) which is internally connected in parallel to the output of the main digital regulator (and is available externally at the VR_DIG pin). This common digital supply voltage is connected to all digital circuit blocks including the SPI and register space. The LPLDO has extremely low quiescent current consumption but limited current supply capability; it is used only in the IDLESTANDBY and IDLE-SLEEP modes. The main digital regulator is automatically enabled in all other modes. SHUTDOWN DWN SHUT IDLE* TX *Five Different Options for IDLE Figure 5. State Machine Diagram Table 10. Operating Modes Response Time State/Mode Response Time to TX Current in State/Mode [µA] Shut Down State 16.8 ms 15 nA Idle States: Standby Mode Sleep Mode Sensor Mode Ready Mode Tune Mode 800 µs 800 µs 800 µs 200 µs 200 µs 450 nA 1 µA 1 µA 800 µA 8.5 mA NA RFM42B: 85 mA @ +20 dBm, RFM43B: 30 mA @ +13 dBm TX State Tel: +86-755-82973805 Fax: +86-755-82973550 E-mail: [email protected] http://www.hoperf.com 13 RFM42B/43B 3.2.1. SHUTDOWN State The SHUTDOWN state is the lowest current consumption state of the device with nominally less than 15 nA of current consumption. The SHUTDOWN state may be entered by driving the SDN pin high. The SDN pin should be held low in all states except the SHUTDOWN state. In the SHUTDOWN state, the contents of the registers are lost and there is no SPI access. When the chip is connected to the power supply, a POR will be initiated after the falling edge of SDN. 3.2.2. IDLE State There are five different modes in the IDLE state which may be selected by "Register 07h. Operating Mode and Function Control 1". All modes have a tradeoff between current consumption and response time to TX mode. This tradeoff is shown in Table 10. After the POR event, SWRESET, or exiting from the SHUTDOWN state the chip will default to the IDLE-READY mode. After a POR event the interrupt registers must be read to properly enter the SLEEP, SENSOR, or STANDBY mode and to control the 32 kHz clock correctly. 3.2.2.1. STANDBY Mode STANDBY mode has the lowest current consumption of the five IDLE states with only the LPLDO enabled to maintain the register values. In this mode the registers can be accessed in both read and write mode. The STANDBY mode can be entered by writing 0h to "Register 07h. Operating Mode and Function Control 1". If an interrupt has occurred (i.e., the nIRQ pin = 0) the interrupt registers must be read to achieve the minimum current consumption. Additionally, the ADC should not be selected as an input to the GPIO in this mode as it will cause excess current consumption. 3.2.2.2. SLEEP Mode In SLEEP mode the LPLDO is enabled along with the Wake-Up-Timer, which can be used to accurately wake-up the radio at specified intervals. See "7.6. Wake-Up Timer" for more information on the Wake - Up - Timer. SLEEP mode is entered by setting enwt = 1 (40h) in "Register 07h. Operating Mode and Function Control 1". If an interrupt has occurred (i.e., the nIRQ pin = 0) the interrupt registers must be read to achieve the minimum current consumption. Also, the ADC should not be selected as an input to the GPIO in this mode as it will cause excess current consumption. 3.2.2.3. SENSOR Mode In SENSOR Mode either the Low Battery Detector, Temperature Sensor, or both may be enabled in addition to the LPLDO and Wake-Up-Timer. The Low Battery Detector can be enabled by setting enlbd = 1 in "Register 07h. Operating Mode and Function Control 1". See "7.4. Temperature Sensor " and "7.5. Low Battery Detector" for more information on these features. If an interrupt has occurred (i.e., the nIRQ pin = 0) the interrupt registers must be read to achieve the minimum current consumption. 3.2.2.4. READY Mode READY Mode is designed to give a fast transition time to TX mode with reasonable current consumption. In this mode the Crystal oscillator remains enabled reducing the time required to switch to TX mode by eliminating the crystal start-up time. READY mode is entered by setting xton = 1 in "Register 07h. Operating Mode and Function Control 1". To achieve the lowest current consumption state the crystal oscillator buffer should be disabled in “Register 62h. Crystal Oscillator Control and Test.” 3.2.2.5. TUNE Mode In TUNE Mode the PLL remains enabled in addition to the other blocks enabled in the IDLE modes. This will give the fastest response to TX mode as the PLL will remain locked but it results in the highest current consumption. This mode of operation is designed for frequency hopping spread spectrum systems (FHSS). TUNE mode is entered by setting pllon = 1 in "Register 07h. Operating Mode and Function Control 1". It is not necessary to set xton to 1 for this mode, the internal state machine automatically enables the crystal oscillator. 14 Tel: +86-755-82973805 Fax: +86-755-82973550 E-mail: [email protected] http://www.hoperf.com RFM42B/43B 3.2.3. TX State The TX state may be entered from any of the IDLE modes when the txon bit is set to 1 in "Register 07h. Operating Mode and Function Control 1". A built-in sequencer takes care of all the actions required to transition between states from enabling the crystal oscillator to ramping up the PA. The following sequence of events will occur automatically when going from STANDBY mode to TX mode by setting the txon bit. 1. Enable the main digital LDO and the Analog LDOs. 2. Start up crystal oscillator and wait until ready (controlled by an internal timer). 3. Enable PLL. 4. Calibrate VCO (this action is skipped when the vcocal bit is “0”, default value is “1”). 5. Wait until PLL settles to required transmit frequency (controlled by timer). 6. Activate power amplifier and wait until power ramping is completed (controlled by an internal timer). 7. Transmit packet. Steps in this sequence may be eliminated depending on which IDLE mode the chip is configured to prior to setting the txon bit. By default, the VCO and PLL are calibrated every time the PLL is enabled. 3.2.4. Device Status Add R/W Function/Description 02 R Device Status D7 D6 D5 D4 D3 ffovfl ffunfl Reserved Reserved freqerr D2 D1 D0 POR Def. cps[1] cps[0] — The operational status of the chip can be read from "Register 02h. Device Status". Tel: +86-755-82973805 Fax: +86-755-82973550 E-mail: [email protected] http://www.hoperf.com 15 RFM42B/43B 3.3. Interrupts The RFM42B/43B is capable of generating an interrupt signal when certain events occur. The chip notifies the microcontroller that an interrupt event has occurred by setting the nIRQ output pin LOW = 0. This interrupt signal will be generated when any one (or more) of the interrupt events (corresponding to the Interrupt Status bits) shown below occur. The nIRQ pin will remain low until the microcontroller reads the Interrupt Status Register(s) (Registers 03h–04h) containing the active Interrupt Status bit. The nIRQ output signal will then be reset until the next change in status is detected. The interrupts must be enabled by the corresponding enable bit in the Interrupt Enable Registers (Registers 05h–06h). All enabled interrupt bits will be cleared when the microcontroller reads the interrupt status register. If the interrupt is not enabled when the event occurs it will not trigger the nIRQ pin, but the status may still be read at anytime in the Interrupt Status registers. Add R/W Function/Descript ion 03 R Interrupt Status 1 04 R Interrupt Status 2 05 R/W Interrupt Enable 1 06 R/W Interrupt Enable 2 D7 D6 D5 D4 ifferr itxffafull itxffaem D3 Reserved iext Reserved Reserved Reserved Reserved iwut enfferr D2 D1 D0 ipksent Reserved Reserved ilbd ichiprdy ipor entxffafull entxffaem Reserved enext enpksent Reserved Reserved Reserved Reserved Reserved Reserved enwut enlbd enchiprdy enpor POR Def. — — 00h 01h See “RFM42B/43B Register Descriptions” for a complete list of interrupts. Tel: +86-755-82973805 16 Fax: +86-755-82973550 E-mail: [email protected] http://www.hoperf.com RFM42B/43B 3.4. System Timing The system timing for TX mode is shown in Figure 6. The figures demonstrate transitioning from STANDBY mode to TX mode through the built-in sequencer of required steps. The user only needs to program the desired mode, and the internal sequencer will properly transition the part from its current mode. TX Packet PA RAMP DOWN PLLTS PRE PA RAMP PA RAMP UP PLL CAL XTAL Settling Time PLL T0 The VCO will automatically calibrate at every frequency change or power up. The PLL T0 time is to allow for bias settling of the VCO. The PLL TS time is for the settling time of the PLL, which has a default setting of 100 µs. The total time for PLL T0, PLL CAL, and PLL TS under all conditions is 200 µs. Under certain applications, the PLL T0 time and the PLL CAL may be skipped for faster turn-around time. Contact applications support if faster turnaround time is desired. Configurable 5-20us, Recommend 5us 1.5Bits @DR Configurable 5-20us, Recommend 5us 6us, Fixed Configurable 0-310us, Recommend 100us 50us, May be skipped Configurable 0-70us, Default = 50us 600us Figure 6. TX Timing Tel: +86-755-82973805 Fax: +86-755-82973550 E-mail: [email protected] http://www.hoperf.com 17 RFM42B/43B 3.5. Frequency Control For calculating the necessary frequency register settings it is recommended that customers use the HOPERF Register Calculator worksheet (in Microsoft Excel) available on the product website. These methods offe r a simple method to quickly determine the correct settings based on the application requirements. The following information can be used to calculated these values manually. 3.5.1. Frequency Programming In order to transmit an RF signal, the desired channel frequency, fcarrier, must be programmed into the RFM42B/43B . Note that this frequency is the center frequency of the desired channel. The carrier frequency is generated by a Fractional-N Synthesizer, using 10 MHz both as the reference frequency and the clock of the (3rd order) ΔΣ modulator. This modulator uses modulo 64000 accumulators. This design was made to obtain the desired frequency resolution of the synthesizer. The overall division ratio of the feedback loop consist of an integer part (N) and a fractional part (F).In a generic sense, the output frequency of the synthesizer is as follows: f OUT 10 MHz ( N F ) The fractional part (F) is determined by three different values, Carrier Frequency (fc[15:0]), Frequency Offset (fo[8:0]), and Frequency Deviation (fd[7:0]). Due to the fine resolution and high loop bandwidth of the synthesizer, FSK modulation is applied inside the loop and is done by varying F according to the incoming data; this is discussed further in "3.5.4. Frequency Deviation" . Also, a fixed offset can be added to fine-tune the carrier frequency and counteract crystal tolerance errors. For simplicity assume that only the fc[15:0] register will determine the fractional component. The equation for selection of the carrier frequency is shown below: f carrier 10 MHz (hbsel 1) ( N F ) fTX 10 MHz * ( hbsel 1) * ( fb[4 : 0] 24 Add R/W Function/Description 73 R/W Frequency Offset 1 74 R/W Frequency Offset 2 75 R/W Frequency Band Select 76 R/W Nominal Carrier Frequency 1 77 R/W Nominal Carrier Frequency 0 fc[15 : 0] ) 64000 D7 D6 D5 D4 D3 D2 fo[7] fo[6] fo[5] fo[4] fo[3] fo[2] D1 D0 POR Def. fo[1] fo[0] 00h fo[9] fo[8] 00h sbsel hbsel fb[4] fb[3] fb[2] fb[1] fb[0] 35h fc[15] fc[14] fc[13] fc[12] fc[11] fc[10] fc[9] fc[8] BBh fc[7] fc[6] fc[5] fc[4] fc[3] fc[2] fc[1] fc[0] 80h The integer part (N) is determined by fb[4:0]. Additionally, the output frequency can be halved by connecting a ÷2 divider to the output. This divider is not inside the loop and is controlled by the hbsel bit in "Register 75h. Frequency Band Select". This effectively partitions the entire 240–960 MHz frequency range into two separate bands: High Band (HB) for hbsel = 1, and Low Band (LB) for hbsel = 0. The valid range of fb[4:0] is from 0 to 23. If a higher value is written into the register, it will default to a value of 23. The integer part has a fixed offset of 24 added to it as shown in the formula above. Table 11 demonstrates the selection of fb[4:0] for the corresponding frequency band. After selection of the fb (N) the fractional component may be solved with the following equation: fTX fc[15 : 0] fb[4 : 0] 24 * 64000 10 MHz * (hbsel 1) fb and fc are the actual numbers stored in the corresponding registers. 18 Tel: +86-755-82973805 Fax: +86-755-82973550 E-mail: [email protected] http://www.hoperf.com RFM42B/43B Table 11. Frequency Band Selection fb[4:0] Value N Frequency Band hbsel=0 hbsel=1 0 24 240–249.9 MHz 480–499.9 MHz 1 25 250–259.9 MHz 500–519.9 MHz 2 26 260–269.9 MHz 520–539.9 MHz 3 27 270–279.9 MHz 540–559.9 MHz 4 28 280–289.9 MHz 560–579.9 MHz 5 29 290–299.9 MHz 580–599.9 MHz 6 30 300–309.9 MHz 600–619.9 MHz 7 31 310–319.9 MHz 620–639.9 MHz 8 32 320–329.9 MHz 640–659.9 MHz 9 33 330–339.9 MHz 660–679.9 MHz 10 34 340–349.9 MHz 680–699.9 MHz 11 35 350–359.9 MHz 700–719.9 MHz 12 36 360–369.9 MHz 720–739.9 MHz 13 37 370–379.9 MHz 740–759.9 MHz 14 38 380–389.9 MHz 760–779.9 MHz 15 39 390–399.9 MHz 780–799.9 MHz 16 40 400–409.9 MHz 800–819.9 MHz 17 41 410–419.9 MHz 820–839.9 MHz 18 42 420–429.9 MHz 840–859.9 MHz 19 43 430–439.9 MHz 860–879.9 MHz 20 44 440–449.9 MHz 880–899.9 MHz 21 45 450–459.9 MHz 900–919.9 MHz 22 46 460–469.9 MHz 920–939.9 MHz 23 47 470–479.9 MHz 940–960 MHz Tel: +86-755-82973805 Fax: +86-755-82973550 E-mail: [email protected] http://www.hoperf.com 19 RFM42B/43B 3.5.2. Easy Frequency Programming for FHSS While Registers 73h–77h may be used to program the carrier frequency of the RFM42B/43B, it is often easier to think in terms of “channels” or “channel numbers” rather than an absolute frequency value in Hz. Also, there may be some timing-critical applications (such as for Frequency Hopping Systems) in which it is desirable to change frequency by programming a single register. Once the channel step size is set, the frequency may be changed by a single register corresponding to the channel number. A nominal frequency is first set using Registers 73h–77h, as described above. Registers 79h and 7Ah are then used to set a channel step size and channel number, relative to the nominal setting. The Frequency Hopping Step Size (fhs[7:0]) is set in increments of 10 kHz with a maximum channel step size of 2.56 MHz. The Frequency Hopping Channel Select Register then selects channels based on multiples of the step size. Fcarrier Fnom fhs[7 : 0] ( fhch[7 : 0] 10kHz ) For example, if the nominal frequency is set to 900 MHz using Registers 73h–77h, the channel step size is set to 1 MHz using "Register 7Ah. Frequency Hopping Step Size," and "Register 79h. Frequency Hopping Channel Select" is set to 5d, the resulting carrier frequency would be 905 MHz. Once the nominal frequency and channel step size are programmed in the registers, it is only necessary to program the fhch[7:0] register in order to change the frequency. Add R/W Function/Description D7 D6 D5 D4 D3 D2 D1 D0 POR Def. 79 R/W Frequency Hopping Channel Select fhch[7] fhch[6] fhch[5] fhch[4] fhch[3] fhch[2] fhch[1] fhch[0] 00h 7A R/W fhs[7] fhs[0] 00h Frequency Hopping Step Size fhs[6] fhs[5] fhs[4] fhs[3] fhs[2] fhs[1] 3.5.3. Automatic State Transition for Frequency Change If registers 79h or 7Ah are changed in TX mode, the state machine will automatically transition the chip back to TUNE and change the frequency. This feature is useful to reduce the number of SPI commands required in a Frequency Hopping System. This in turn reduces microcontroller activity, reducing current consumption. The exception to this is during TX FIFO mode. If a frequency change is initiated during a TX packet, then the part will complete the current TX packet and will only change the frequency for subsequent packets. 3.5.4. Frequency Deviation The peak frequency deviation is configurable from ±0.625 to ±320 kHz. The Frequency Deviation (Δf) is controlled by the Frequency Deviation Register (fd), address 71 and 72h, and is independent of the carrier frequency setting. When enabled, regardless of the setting of the hbsel bit (high band or low band), the resolution of the frequency deviation will remain in increments of 625 Hz. When using frequency modulation the carrier frequency will deviate from the nominal center channel carrier frequency by ±Δf: f fd [8 : 0] 625Hz f fd [8 : 0] f = peak deviation 625Hz 20 Tel: +86-755-82973805 Fax: +86-755-82973550 E-mail: [email protected] http://www.hoperf.com RFM42B/43B Frequency f fcarrier Time Figure 7. Frequency Deviation The previous equation should be used to calculate the desired frequency deviation. If desired, frequency modulation may also be disabled in order to obtain an unmodulated carrier signal at the channel center frequency; see "4.1. Modulation Type" for further details. Add R/W Function/Description D7 D6 D5 D4 D3 D2 D1 D0 POR Def. 71 R/W Modulation Mode Control 2 trclk[1] trclk[0] dtmod[1] dtmod[0] eninv fd[8] modtyp[1] modtyp[0] 00h 72 R/W 20h Frequency Deviation Tel: +86-755-82973805 fd[7] fd[6] Fax: +86-755-82973550 fd[5] fd[4] fd[3] fd[2] fd[1] fd[0] E-mail: [email protected] http://www.hoperf.com 21 RFM42B/43B 3.5.5. Frequency Offset Adjustment A frequency offset can be adjusted manually by fo[9:0] in registers 73h and 74h. The frequency offset adjustment is implemented by shifting the Synthesizer Local Oscillator frequency. This register is a signed register so in order to get a negative offset it is necessary to take the twos complement of the positive offset number. The offset can be calculated by the following: DesiredOffset 156.25 Hz (hbsel 1) fo[9 : 0] fo[9 : 0] DesiredOffset 156.25Hz (hbsel 1) The adjustment range in high band is ±160 kHz and in low band it is ±80 kHz. For example to compute an offset of +50 kHz in high band mode fo[9:0] should be set to 0A0h. For an offset of –50 kHz in high band mode the fo[9:0] register should be set to 360h. Add R/W Function/Descript ion 73 R/W Frequency Offset 74 R/W Frequency Offset D7 D6 D5 D4 D3 D2 D1 D0 POR Def. fo[7] fo[6] fo[5] fo[4] fo[3] fo[2] fo[1] fo[0] 00h fo[9] fo[8] 00h 3.5.6. TX Data Rate Generator The data rate is configurable between 0.123–256 kbps. For data rates below 30 kbps the ”txdtrtscale” bit in register 70h should be set to 1. When higher data rates are used this bit should be set to 0. The TX date rate is determined by the following formula in kbps: txdr 15:0 1 MHzDR_TX (kbps) = -------------------------------------------------16 + 5 txdtrtscale 2 16 + 5 txdtrtscale DR_TX(kbps) 2 txdr[15:0] = --------------------------------------------------------------------------------------1 MHz Add R/W Function/Description D7 D6 D5 D4 D3 D2 D1 D0 POR Def. 6E R/W TX Data Rate 1 txdr[15] txdr[14] txdr[13] txdr[12] txdr[11] txdr[10] txdr[9] txdr[8] 0Ah 6F R/W TX Data Rate 0 txdr[7] txdr[6] txdr[2] txdr[1] txdr[0] AAh 22 Tel: +86-755-82973805 txdr[5] Fax: +86-755-82973550 txdr[4] txdr[3] E-mail: [email protected] http://www.hoperf.com RFM42B/43B 4. Modulation Options 4.1. Modulation Type The RFM42B/43B supports three different modulation options: Gaussian Frequency Shift Keying (GFSK), Frequency Shift Keying (FSK), and On-Off Keying (OOK). GFSK is the recommended modulation type as it provides the best performance and cleanest modulation spectrum. Figure 8 demonstrates the difference between FSK and GFSK for a Data Rate of 64 kbps. The time domain plots demonstrate the effects of the Gaussian filtering. The frequency domain plots demonstrate the spectral benefit of GFSK over FSK. The type of modulation is selected with the modtyp[1:0] bits in "Register 71h. Modulation Mode Control 2." Note that it is also possible to obtain an unmodulated carrier signal by setting modtyp[1:0] = 00. modtyp[1:0] Modulation Source 00 Unmodulated Carrier 01 OOK 10 FSK 11 GFSK (enable TX Data CLK when direct mode is used) TX Modulation Time Domain Waveforms -- FSK vs. GFSK TX Modulation Spectrum -- FSK vs GFSK (Continuous PRBS) -20 ModSpectrum_FSK 1.0 0.5 0.0 -0.5 -1.0 -40 -60 -80 -1.5 -100 1.0 -20 ModSpectrum_GFSK SigData_GFSK[0,::] SigData_FSK[0,::] 1.5 0.5 0.0 -0.5 -1.0 0 50 100 150 200 250 300 350 400 450 500 -40 -60 -80 -100 -250 -200 -150 -100 -50 0 50 100 150 200 250 freq, KHz time, usec DataRate TxDev 64000.0 32000.0 BT_Filter 0.5 ModIndex 1.0 Figure 8. FSK vs. GFSK Spectrums Tel: +86-755-82973805 Fax: +86-755-82973550 E-mail: [email protected] http://www.hoperf.com 23 RFM42B/43B 4.2. Modulation Data Source The RFM42B/43B may be configured to obtain its modulation data from one of three different sources:FIFO mode, Direct Mode, and from a PN9 mode. In Direct Mode, the TX modulation data may be obtained from several different input pins. These options are set through the dtmod[1:0] field in "Register 71h. Modulation Mode Control 2." Add R/W Function/Description 71 R/W Modulation Mode Control 2 D7 D6 D5 D4 D3 D2 D1 D0 trclk[1] trclk[0] dtmod[1] dtmod[0] eninv fd[8] modtyp[1] modtyp[0] POR Def. 00h Data Source dtmod[1:0] 00 Direct Mode using TX Data via GPIO pin (GPIO configuration required) 01 Direct Mode using TX Data via SDI pin (only when nSEL is high) 10 FIFO Mode 11 PN9 (internally generated) 4.2.1. FIFO Mode In FIFO mode, the transmit data is stored in integrated FIFO register memory. The FIFOs are accessed via "Register 7Fh. FIFO Access," and are most efficiently accessed with burst read/write operation as discussed in "3.1. Serial Peripheral Interface (SPI)". In TX mode, the data bytes stored in FIFO memory are "packaged" together with other fields and bytes of information to construct the final transmit packet structure. These other potential fields include the Preamble, Sync word, Header, CRC checksum, etc. The configuration of the packet structure in TX mode is determined by the Automatic Packet Handler (if enabled), in conjunction with a variety of Packet Handler Registers (see Table12). If the Automatic Packet Handler is disabled, the entire desired packet structure should be loaded into FIFO memory; no other fields (such as Preamble or Sync word are automatically added to the bytes stored in FIFO memory). For further information on the configuration of the FIFOs for a specific application or packet size, see "6. Data Handling and Packet Handler" . When in FIFO mode, the chip will automatically exit the TX State when either the ipksent or ipkvalid interrupt occurs. The chip will return to the IDLE mode state programmed in "Register 07h. Operating Mode and Function Control 1". For example, the chip may be placed into TX mode by setting the txon bit, but with the pllon bit additionally set. The chip will transmit all of the contents of the FIFO and the ipksent interrupt will occur. When this interrupt event occurs, the chip will clear the txon bit and return to TUNE mode, as indicated by the set state of the pllon bit. If no other bits are additionally set in register 07h (besides txon initially), then the chip will return to the STANDBY state. 24 Tel: +86-755-82973805 Fax: +86-755-82973550 E-mail: [email protected] http://www.hoperf.com RFM42B/43B 4.2.2. Direct Mode For legacy systems that perform packet handling within an MCU or other baseband chip, it may not be desirable to use the FIFO. For this scenario, a Direct Mode is provided which bypasses the FIFOs entirely. In TX direct mode, the TX modulation data is applied to an input pin of the chip and processed in "real time" (i.e., not stored in a register for transmission at a later time). A variety of pins may be configured for use as the TX Data input function. Furthermore, an additional pin may be required for a TX Clock output function if GFSK modulation is desired (only the TX Data input pin is required for FSK). Two options for the source of the TX Data are available in the dtmod[1:0] field, and various configurations for the source of the TX Data Clock may be selected through the trclk[1:0] field. trclk[1:0] 00 01 10 11 TX Data Clock Configuration No TX Clock (only for FSK) TX Data Clock is available via GPIO (GPIO needs programming accordingly as well) TX Data Clock is available via SDO pin (only when nSEL is high) TX Data Clock is available via the nIRQ pin The eninv bit in SPI Register 71h will invert the TX Data; this is most likely useful for diagnostic and testing purposes. 4.2.2.1. Direct Synchronous Mode In TX direct mode, the chip may be configured for synchronous or asynchronous modes of modulation. In direct synchronous mode, the RFIC is configured to provide a TX Clock signal as an output to the external device that is providing the TX Data stream. This TX Clock signal is a square wave with a frequency equal to the programmed data rate. The external modulation source (e.g., MCU) must accept this TX Clock signal as an input and respond by providing one bit of TX Data back to the RFIC, synchronous with one edge of the TX Clock signal. In this fashion, the rate of the TX Data input stream from the external source is controlled by the programmed data rate of the RFIC; no TX Data bits are made available at the input of the RFIC until requested by another cycle of the TX Clock signal. The TX Data bits supplied by the external source are transmitted directly in real-time (i.e., not stored internally for later transmission). All modulation types (FSK/GFSK/OOK) are valid in TX direct synchronous mode. As will be discussed in the next section, there are limits on modulation types in TX direct asynchronous mode. 4.2.2.2. Direct Asynchronous Mode In TX direct asynchronous mode, the RFIC no longer controls the data rate of the TX Data input stream. Instead, the data rate is controlled only by the external TX Data source; the RFIC simply accepts the data applied to its TX Data input pin, at whatever rate it is supplied. This means that there is no longer a need for a TX Clock output signal from the RFIC, as there is no synchronous "handshaking" between the RFIC and the external data source. The TX Data bits supplied by the external source are transmitted directly in real-time (i.e., not stored internally for later transmission). It is not necessary to program the data rate parameter when operating in TX direct asynchronous mode. The chip still internally samples the incoming TX Data stream to determine when edge transitions occur; however, rather than sampling the data at a pre-programmed data rate, the chip now internally samples the incoming TX Data stream at its maximum possible oversampling rate. This allows the chip to accurately determine the timing of the bit edge transitions without prior knowledge of the data rate. (Of course, it is still necessary to program the desired peak frequency deviation.) Only FSK and OOK modulation types are valid in TX Direct Asynchronous Mode; GFSK modulation is not available in asynchronous mode. This is because the RFIC does not have knowledge of the supplied data rate, and thus cannot determine the appropriate Gaussian lowpass filter function to apply to the incoming data. One advantage of this mode that it saves a microcontroller pin because no TX Clock output function is required. The primary disadvantage of this mode is the increase in occupied spectral bandwidth with FSK (as compared to GFSK). Tel: +86-755-82973805 Fax: +86-755-82973550 E-mail: [email protected] http://www.hoperf.com 25 RFM42B/43B 4.2.2.3. Direct Mode using SPI or nIRQ Pins In certain applications it may be desirable to minimize the connections to the microcontroller or to preserve the GPIOs for other uses. For these cases it is possible to use the SPI pins and nIRQ as the modulation clock and data. The SDO pin can be configured to be the data clock by programming trclk = 10. If the nSEL pin is LOW then the function of the pin will be SPI data output. If the pin is high and trclk[1:0] is 10 then during TX mode the data clock will be available on the SDO pin. If trclk[1:0] is set to 11 and no interrupts are enabled in registers 05 or 06h, then the nIRQ pin can also be used as the TX data clock. The SDI pin can be configured to be the data source in TX mode if dtmod[1:0] = 01. In a similar fashion, if nSEL is LOW the pin will function as SPI data-in. If nSEL is HIGH then in TX mode it will be the data to be modulated and transmitted. Figure 9 demonstrates using SDI and SDO as the TX data and clock: TX on command TX mode TX off command TX on command TX mode TX off command nSEL SDI SPI input don’t care SPI input MOD input SPI input don’t care SPI input MOD output SPI input SDO SPI output don’t care SPI output Data CLK Output SPI output don’t care SPI output Data CLK Output SPI output Figure 9. Microcontroller Connections If the SDO pin is not used for data clock then it may be programmed to be the interrupt function (nIRQ) by programming Reg 0Eh bit 3. 4.2.3. PN9 Mode In this mode the TX Data is generated internally using a pseudorandom (PN9 sequence) bit generator. The primary purpose of this mode is for use as a test mode to observe the modulated spectrum without having to provide data. 26 Tel: +86-755-82973805 Fax: +86-755-82973550 E-mail: [email protected] http://www.hoperf.com RFM42B/43B 5. Internal Functional Blocks This section provides an overview some of the key blocks of the internal radio architecture. 5.1. Synthesizer An integrated Sigma Delta (ΣΔ) Fractional-N PLL synthesizer capable of operating from 240–960 MHz is provided on-chip. Using a ΣΔ synthesizer has many advantages; it provides flexibility in choosing data rate, deviation, channel frequency, and channel spacing. The transmit modulation is applied directly to the loop in the digital domain through the fractional divider which results in very precise accuracy and control over the transmit deviation. Depending on the part, the PLL and - modulator scheme is designed to support any desired frequency and channel spacing in the range from 240–960 MHz with a frequency resolution of 156.25 Hz (Low band) or 312.5 Hz (High band). The transmit data rate can be programmed between 0.123–256 kbps, and the frequency deviation can be programmed between ±1–320 kHz. These parameters may be adjusted via registers as shown in "3.5. Frequency Control". Fref = 10 M PFD CP Selectable Divider LPF TX VCO N TX Modulation DeltaSigma Figure 10. PLL Synthesizer Block Diagram The reference frequency to the PLL is 10 MHz. The PLL utilizes a differential L-C VCO, with integrated on-chip inductors. The output of the VCO is followed by a configurable divider which will divide down the signal to the desired output frequency band. The modulus of this divider stage is controlled dynamically by the output from the - modulator. The tuning resolution is sufficient to tune to the commanded frequency with a maximum accuracy of 312.5 Hz anywhere in the range between 240–960 MHz. 5.1.1. VCO The output of the VCO is automatically divided down to the correct output frequency depending on the hbsel and fb[4:0] fields in "Register 75h. Frequency Band Select." The VCO integrates the resonator inductor, tuning varactor, so no external VCO components are required. The VCO uses a capacitance bank to cover the wide frequency range specified. The capacitance bank will automatically be calibrated every time the synthesizer is enabled. In certain fast hopping applications this might not be desirable so the VCO calibration may be skipped by setting the appropriate register. 5.2. Power Amplifier The RFM42B contains an internal integrated power amplifier(PA) capable of transmitting at output levels between-1 and +20dBm. The RFM43B contains a PA which is capable of transmitting output levels between –8 to +13 dBm. The PA can chang the output power by adjusting txpow[2:0] will scale both the output power and current but the efficiency will not be constant. The PA output is ramped up and down to prevent unwanted spectral splatter. Tel: +86-755-82973805 Fax: +86-755-82973550 E-mail: [email protected] http://www.hoperf.com 27 RFM42B/43B 5.2.1. Output Power Selection With the RFM42B,the output power is configurable in 3 dB steps with the txpow[2:0] field in "Register 6Dh. TX Power." Extra output power can allow the use of a cheaper, smaller antenna reducing the overall BOM cost. The higher power setting of the chip achieves maximum possible range, but of course comes at the cost of higher TX current consumption. However, depending on the duty cycle of the system, the effect on battery life may be insignificant. Contact HOPERF Support for help in evaluating this tradeoff. The +13 dBm output power of the RF43B is targeted at systems that require lower output power. The PA still offers high efficiency and a range of output power from –8 to +13 dBm. Add R/W Function/Description 6D R/W D7 D6 D5 D3 TX Power txpow[2:0] Tel: +86-755-82973805 +1 dBm 001 +2 dBm 010 +5 dBm 011 +8 dBm 100 +11 dBm 101 +14 dBm 110 +17 dBm 111 +20 dBm D1 D0 POR Def. txpow[2] txpow[1] txpow[0] 07h RFM43B Output Power 000 –8 dBm 001 –5 dBm 010 –2 dBm 011 +1 dBm 100 +4 dBm 101 +7 dBm 110 +10 dBm 111 +13 dBm Fax: +86-755-82973550 D2 RFM42B Output Power 000 txpow[2:0] 28 D4 E-mail: [email protected] http://www.hoperf.com RFM42B/43B 5.3. Crystal Oscillator The RFM42B/43B includes an integrated 30 MHz crystal oscillator with a fast start-up time of less than 600 µs A parallel resonant 30MHz crystal is used on the module. Th e design is differential with the required crystal load capacitance integrated on-chip to minimize the number of external components. The crystal load capacitance can be digitally programmed to accommodate crystals with various load capacitance requirements and to adjust the frequency of the crystal oscillator. The tuning of the crystal load capacitance is programmed through the xlc[6:0] field of "Register 09h. 30 MHz Crystal Oscillator Load Capacitance." The total internal capacitance is 12.5 pF and is adjustable in approximately 127 steps (97fF/step). The xtalshift bit is a coarse shift in frequency but is not binary with xlc[6:0]. The crystal frequency adjustment can be used to compensate for crystal production tolerances. Utilizing the onchip temperature sensor and suitable control software, the temperature dependency of the crystal can be canceled. The typical value of the total on-chip capacitance Cint can be calculated as follows: Cint = 1.8 pF + 0.085 pF x xlc[6:0] + 3.7 pF x xtalshift Note that the coarse shift bit xtalshift is not binary with xlc[6:0]. The total load capacitance Cload seen by the crystal can be calculated by adding the sum of all external parasitic PCB capacitances Cext to Cint. If the maximum value of Cint (16.3pF) is not sufficient, an external capacitor can be added for exact tuning. The crystal oscillator frequency is divided down internally and may be output to the microcontroller through one of the GPIO pins for use as the System Clock. In this fashion, only one crystal oscillator is required for the entire system and the BOM cost is reduced. The available clock frequencies and GPIO configuration are discussed further in "7.2. Microcontroller Clock" . Add R/W Function/Description 09 R/W Crystal Oscillator Load Capacitance D7 D6 D5 D4 D3 D2 D1 D0 POR Def. xtalshift xlc[6] xlc[5] xlc[4] xlc[3] xlc[2] xlc[1] xlc[0] 40h 5.4. Regulators There are a total of four regulators integrated onto the RFM42B/43B.With the exception of the digital regulator, all regulators are designed to operate with only internal decoupling. All regulators are designed to operate with an input supply voltage from +1.8 to +3.6V. A supply voltage should only be connected to the VDD pins. Tel: +86-755-82973805 Fax: +86-755-82973550 E-mail: [email protected] http://www.hoperf.com 29 RFM42B/43B 6. Data Handling and Packet Handler The internal modem is designed to operate with a packet including a 10101... preamble structure. To configure the modem to operate with packet formats without a preamble or other legacy packet structures contact customer support. 6.1. TX FIFO A 64 byte FIFO is integrated into the chip for TX, as shown in Figure 11. "Register 7Fh. FIFO Access" is used to access the FIFO. A burst write, as described in "3.1. Serial Peripheral Interface (SPI) " , to address 7Fh will write data to the TX FIFO. TX FIFO TX FIFO Almost Full Threshold TX FIFO Almost Empty Threshold Figure 11. FIFO Threshold The TX FIFO has two programmable thresholds. An interrupt event occurs when the data in the TX FIFO reaches these thresholds. The first threshold is the FIFO almost full threshold, txafthr[5:0]. The value in this register corresponds to the desired threshold value in number of bytes. When the data being filled into the TX FIFO crosses this threshold limit, an interrupt to the microcontroller is generated so the chip can enter TX mode to transmit the contents of the TX FIFO. The second threshold for TX is the FIFO almost empty Threshold, txaethr[5:0]. When the data being shifted out of the TX FIFO drops below the almost empty threshold an interrupt will be generated. The microcontroller will need to switch out of TX mode or fill more data into the TX FIFO. The transceiver can be configured so that when the TX FIFO is empty it will automatically exit the TX state and return to one of the low power states. When TX is initiated, it will transmit the number of bytes programmed into the packet length field (Reg 3Eh). When the packet ends, the chip will return to the state specified in register 07h. For example, if 08h is written to address 07h then the chip will return to the STANDBY state. If 09h is written then the chip will return to the READY state. 30 Tel: +86-755-82973805 Fax: +86-755-82973550 E-mail: [email protected] http://www.hoperf.com RFM42B/43B Add R/W Function/D escription D7 D6 D5 D4 D3 Operating & Reserved Reserved Reserved Reserved Function Control 2 D1 Reserved Reserved D0 POR Def. ffclrtx 00h 08 R/W 7C R/W TX FIFO Control 1 Reserved Reserved txafthr[5] txafthr[3] txafthr[2] txafthr[1] txafthr[0] 37h 7D R/W TX FIFO Control 2 Reserved Reserved txaethr[5] txaethr[4] txaethr[3] txaethr[2] txaethr[1] txaethr[0] 04h txafthr[4] autotx D2 The TX FIFO may be cleared or reset with the ffclrtx bit in “Register 08h. Operating Mode and Function Control 2.” All interrupts may be enabled by setting the Interrupt Enabled bits in "Register 05h. Interrupt Enable 1" and “Register 06h. Interrup t Enable 2,”. If the interrupts are not enabled the function will not generate an interrupt on the nIRQ pin but the bits will still be read correctly in the Interrupt Status registers. 6.2. Packet Configuration When using the FIFO, automatic packet handling may be enabled for the TX mode. "Register 30h. Data Access Control" through “Register 3Eh. Packet Length,” control the configuration for Packet Handling. The usual fields for network communication (such as preamble, synchronization word, headers, packet length, and CRC) can be configured to be automatically added to the data payload. The fields needed for packet generation normally change infrequently and can therefore be stored in registers. Automatically adding these fields to the data payload greatly reduces the amount of communication between the microcontroller and the RF 42B/43B and reduces the required computational power of the microcontroller. Data CRC 1-4 Bytes 0 or 2 Bytes 0 or 1 Byte 0-4 Bytes 1-512 Bytes Packet Length Preamble TX Header Sync Word The general packet structure is shown in Figure 12. The length of each field is shown below the field. The preamble pattern is always a series of alternating ones and zeroes, starting with a zero. All the fields have programmable lengths to accommodate different applications. The most common CRC polynominals are available for selection. Figure 12. Packet Structure An overview of the packet handler configuration registers is shown in Table 12. 6.3. Packet Handler TX Mode If the TX packet length is set the packet handler will send the number of bytes in the packet length field before returning to IDLE mode and asserting the packet sent interrupt. To resume sending data from the FIFO the microcontroller needs to command the chip to re-enter TX mode. Figure 14 provides an example transaction where the packet length is set to three bytes. Tel: +86-755-82973805 Fax: +86-755-82973550 E-mail: [email protected] http://www.hoperf.com 31 RFM42B/43B D ata D ata D ata D ata D ata D ata D ata D ata D ata 1 2 3 4 5 6 7 8 9 } } } This w ill be sent in the first transm ission This w ill be sent in the second transm ission This w ill be sent in the third transm ission Figure 13. Multiple Packets in TX Packet Handler Table 12. Packet Handler Registers Add R/W Function/Description D7 D6 D5 D4 D3 D2 D1 D0 POR Def. 30 R/W Data Access Control Reserved lsbfrst crcdonly skip2ph enpactx encrc crc[1] crc[0] 8Dh 31 R EzMAC status 0 Reserved Reserved Reserved Reserved Reserved pktx pksent — 32 Reserved 33 R/W Header Control 2 skipsyn hdlen[2] hdlen[1] hdlen[0] fixpklen synclen[1] synclen[0] prealen[8] 22h 34 R/W Preamble Length prealen[7] prealen[6] prealen[5] prealen[4] prealen[3] prealen[2] prealen[1] prealen[0] 08h 36 R/W Sync Word 3 sync[31] sync[30] sync[29] sync[28] sync[27] sync[26] sync[25] sync[24] 2Dh 37 R/W Sync Word 2 sync[23] sync[22] sync[21] sync[20] sync[19] sync[18] sync[17] sync[16] D4h 38 R/W Sync Word 1 sync[15] sync[14] sync[13] sync[12] sync[11] sync[10] sync[9] sync[8] 00h 39 R/W Sync Word 0 sync[7] sync[6] sync[5] sync[4] sync[3] sync[2] sync[1] sync[0] 00h 3A R/W Transmit Header 3 txhd[31] txhd[30] txhd[29] txhd[28] txhd[27] txhd[26] txhd[25] txhd[24] 00h 3B R/W Transmit Header 2 txhd[23] txhd[22] txhd[21] txhd[20] txhd[19] txhd[18] txhd[17] txhd[16] 00h 3C R/W Transmit Header 1 txhd[15] txhd[14] txhd[13] txhd[12] txhd[11] txhd[10] txhd[9] txhd[8] 00h 3D R/W Transmit Header 0 txhd[7] txhd[6] txhd[5] txhd[4] txhd[3] txhd[2] txhd[1] txhd[0] 00h 3E R/W Transmit Packet Length pklen[7] pklen[6] pklen[5] pklen[4] pklen[3] pklen[2] pklen[1] pklen[0] 00h 32 Tel: +86-755-82973805 Fax: +86-755-82973550 E-mail: [email protected] http://www.hoperf.com RFM42B/43B 6.4. Data Whitening, Manchester Encoding, and CRC Data whitening can be used to avoid extended sequences of 0s or 1s in the transmitted data stream to achieve a more uniform spectrum. When enabled, the payload data bits are XORed with a pseudorandom sequence output from the built-in PN9 generator. The generator is initialized at the beginning of the payload. The receiver recovers the original data by repeating this operation. Manchester encoding can be used to ensure a dc-free transmission and good synchronization properties. When Manchester encoding is used, the effective datarate is unchanged but the actual datarate (preamble length, etc.) is doubled due to the nature of the encoding. The effective datarate when using Manchester encoding is limited to 128 kbps. The implementation of Manchester encoding is shown in Figure 15. Data whitening and Manchester encoding can be selected with "Register 70h. Modulation Mode Control 1". The CRC is configured via "Register 30h. Data Access Control". Figure 14 demonstrates the portions of the packet which have Manchester encoding, data whitening, and CRC applied. CRC can be applied to only the data portion of the packet or to the data, packet length and header fields. Figure 15 provides an example of how the Manchester encoding is done and also the use of the Manchester invert (enmaniv) function. Manchester Whitening CRC CRC (Over data only) Preamble Sync Header/ Address PK Length Data CRC Figure 14. Operation of Data Whitening, Manchester Encoding, and CRC Data before Manchester 1 1 1 1 1 Preamble = 0xFF 1 1 1 0 0 0 1 0 First 4bits of the synch. word = 0x2 Data after Machester ( manppol = 1, enmaninv = 0) Data after Machester ( manppol = 1, enmaninv = 1) Data before Manchester 0 0 0 0 0 Preamble = 0x00 0 0 0 0 0 0 1 0 First 4bits of the synch. word = 0x2 Data after Machester ( manppol = 0, enmaninv = 0) Data after Machester ( manppol = 0, enmaninv = 1) Figure 15. Manchester Coding Example 6.5. Synchronization Word Configuration The synchronization word length can be configured in Reg 33h, synclen[1:0]. The expected or transmitted sync word can be configured from 1 to 4 bytes as defined below: synclen[1:0] = 00—Transmitted Synchronization Word (sync word) 3. synclen[1:0] = 01—Transmitted Synchronization Word 3 first, followed by sync word 2. synclen[1:0] = 10—Transmitted Synchronization Word 3 first, followed by sync word 2, followed by sync word 1. synclen[1:0] = 1—Transmitted Synchronization Word 3 first, followed by sync word 2, followed by sync word 1, followed by sync word 0. The sync is transmitted in the following sequence: sync 3sync 2sync 1sync 0. The sync word values can be programmed in Registers 36h–39h. Tel: +86-755-82973805 Fax: +86-755-82973550 E-mail: [email protected] http://www.hoperf.com 33 RFM42B/43B 6.6. TX Retransmission and Auto TX The RFM42B/43B is capable of automatically retransmitting the last packet loaded in the TX FIFO. Automatic retransmission is set by entering the TX state with the txon bit without reloading the TX FIFO. This feature is useful for beacon transmission or when retransmission is required due to the absence of a valid acknowledgement. Only packets that fit completely in the TX FIFO can be automatically retransmitted. An automatic transmission function is available, allowing the radio to automatically start or stop a transmission depending on the amount of data in the TX FIFO. When autotx is set in “Register 08. Operating & Function Control 2," the transceiver will automatically enter the TX state when the TX FIFO almost full threshold is exceeded. Packets will be transmitted according to the configured packet length. To stop transmitting, clear the packet sent or TX FIFO almost empty interrupts must be cleared by reading register. 34 Tel: +86-755-82973805 Fax: +86-755-82973550 E-mail: [email protected] http://www.hoperf.com RFM42B/43B 7. Auxiliary Functions 7.1. Smart Reset The RFM42B/43B contains an enhanced integrated SMART RESET or POR circuit. The POR circuit contains both a classic level threshold reset as well as a slope detector POR. This reset circuit was designed to produce a reliable reset signal under any circumstances. Reset will be initiated if any of the following conditions occur: Initial power on, VDD starts from gnd: reset is active till VDD reaches VRR (see table); When VDD decreases below VLD for any reason: reset is active till VDD reaches VRR; A software reset via “Register 08h. Operating Mode and Function Control 2,”: reset is active for time TSWRST VDD glitch when the supply voltage exceeds the following time functioned limit: VDD nom. VDD(t) reset limit: 0.4V+t*0.2V/ms actual VDD(t) showing glitch 0.4V Reset TP t t=0, VDD starts to rise reset: Vglitch>=0.4+t*0.2V/ms Figure 16. POR Glitch Parameters Table 13. POR Parameters Parameter Symbol Comment Min Typ Max Unit 0.85 1.3 1.75 V Release Reset Voltage VRR Power-On VDD Slope SVDD tested VDD slope region 0.03 — 300 V/ms VLD VLD<VRR is guaranteed 0.7 1 1.3 V TSWRST 50 — 470 µs Threshold Voltage VTSD — 0.4 — V Reference Slope k — 0.2 — V/ms 5 15 40 ms Low VDD Limit Software Reset Pulse VDD Glitch Reset Pulse TP Also occurs after SDN, and initial power on The reset will initialize all registers to their default values. The reset signal is also available for output and use by the microcontroller by using the default setting for GPIO_0. The inverted reset signal is available by default on GPIO_1. Tel: +86-755-82973805 Fax: +86-755-82973550 E-mail: [email protected] http://www.hoperf.com 35 RFM42B/43B 7.2. Microcontroller Clock The 30 MHz crystal oscillator frequency is divided down internally and may be output to the microcontroller through GPIO2. This feature is useful to lower BOM cost by using only one crystal in the system. The system clock frequency is selectable from one of 8 options, as shown below. Except for the 32.768 kHz option, all other frequencies are derived by dividing the crystal oscillator frequency. The 32.768 kHz clock signal is derived from an internal RC oscillator or an external 32 kHz crystal. The default setting for GPIO2 is to output the microcontroller clock signal with a frequency of 1 MHz. Add R/W 0A R/W D7 Function/Description D6 Microcontroller Output Clock D5 D4 D3 clkt[1] clkt[0] enlfc mclk[2:0] Clock Frequency 000 30 MHz 001 15 MHz 010 10 MHz 011 4 MHz 100 3 MHz 101 2 MHz 110 1 MHz 111 32.768 kHz D2 D1 D0 mclk[2] mclk[1] mclk[0] POR Def. 0Bh If the microcontroller clock option is being used there may be the need of a system clock for the microcontroller while the RFM42B/43B is in SLEEP mode. Since the crystal oscillator is disabled in SLEEP mode in order to save current, the low-power 32.768 kHz clock can be automatically switched to become the microcontroller clock. This feature is called enable low frequency clock and is enabled by the enlfc bit in “Register 0Ah. Microcontroller Output Clock." When enlfc = 1 and the chip is in SLEEP mode then the 32.768 kHz clock will be provided to the microcontroller as the system clock, regardless of the setting of mclk[2:0]. For example, if mclk[2:0] = 000, 30 MHz will be provided through the GPIO output pin to the microcontroller as the system clock in all IDLE or TX states. When the chip enters SLEEP mode, the system clock will automatically switch to 32.768 kHz from the RC oscillator or 32.768 XTAL. Another available feature for the microcontroller clock is the clock tail, clkt[1:0] in “Register 0Ah. Microcontroller Output Clock." If the low frequency clock feature is not enabled (enlfc = 0), then the system clock to the microcontroller is disabled in SLEEP mode. However, it may be useful to provide a few extra cycles for the microcontroller to complete its operation prior to the shutdown of the system clock signal. Setting the clkt[1:0] field will provide additional cycles of the system clock before it shuts off. clkt[1:0] Clock Tail 00 0 cycles 01 128 cycles 10 256 cycles 11 512 cycles If an interrupt is triggered, the microcontroller clock will remain enabled regardless of the selected mode. As soon as the interrupt is read the state machine will then move to the selected mode. The minimum current consumption will not be achieved until the interrupt is read. For instance, if the chip is commanded to SLEEP mode but an interrupt has occurred the 30 MHz XTAL will not be disabled until the interrupt has been cleared. 36 Tel: +86-755-82973805 Fax: +86-755-82973550 E-mail: [email protected] http://www.hoperf.com RFM42B/43B 7.3. General Purpose ADC An 8-bit SAR ADC is integrated for general purpose use, as well as for digitizing the on-chip temperature sensor reading. Registers 0Fh "ADC Configuration", 10h "Sensor Offset" and 4Fh "Amplifier Offset" can be used to configure the ADC operation. Every time an ADC conversion is desired, bit 7 "adcstart/adcbusy" in “Register 1Fh. Clock Recovery Gearshift Override” must be set to 1. This is a self clearing bit that will be reset to 0 at the end of the conversion cycle of the ADC. The conversion time for the ADC is 350 µs. After this time or when the "adcstart/adcbusy" bit is cleared, then the ADC value may be read out of “Register 11h. ADC Value." The architecture of the ADC is shown in Figure 17. The signal and reference inputs of the ADC are selected by adcsel[2:0] and adcref[1:0] in register 0Fh “ADC Configuration”, respectively. The default setting is to read out the temperature sensor using the bandgap voltage (VBG) as reference. With the VBG reference the input range of the ADC is from 0-1.02 V with an LSB resolution of 4 mV (1.02/255). Changing the ADC reference will change the LSB resolution accordingly. A differential multiplexer and amplifier are provided for interfacing external bridge sensors. The gain of the amplifier is selectable by adcgain[1:0] in Register 0Fh. The majority of sensor bridges have supply voltage (VDD) dependent gain and offset. The reference voltage of the ADC can be changed to either VDD/2 or VDD/3. A programmable VDD dependent offset voltage can be added using soffs[3:0] in register 10h. Diff. MUX Diff. Amp. … … Input MUX aoffs [4:0] adcsel [2:0] adcgain [1:0] … GPIO0 GPIO1 GPIO2 soffs [3:0] 8-bit ADC Temperature Sensor Vin adcsel [2:0] Vref 0 -1020mV / 0-255 Ref MUX … VDD / 3 VDD / 2 VBG (1.2V) adc [7:0] adcref [1:0] Figure 17. General Purpose ADC Architecture Add R/W Function/Description D7 0F R/W ADC Configuration adcstart/adcbusy 10 R/W Sensor Offset 11 R ADC Value Tel: +86-755-82973805 adc[7] D6 D5 adcsel[2] adcsel[1] adc[6] Fax: +86-755-82973550 adc[5] D4 D3 D2 adcsel[0] adcref[1] adcref[0] soffs[3] soffs[2] soffs[1] soffs[0] 00h adc[3] adc[2] adc[1] adc[0] — adc[4] D1 D0 POR Def. adcgain[1] adcgain[0] E-mail: [email protected] http://www.hoperf.com 00h 37 RFM42B/43B 7.4. Temperature Sensor An integrated on-chip analog temperature sensor is available. The temperature sensor will be automatically enabled when the temperature sensor is selected as the input of the ADC or when the analog temp voltage is selected on the analog test bus. The temperature sensor value may be digitized using the general-purpose ADC and read out over the SPI through "Register 10h. ADC Sensor Amplifier Offset." The range of the temperature sensor is configurable. Table 14 lists the settings for the different temperature ranges and performance. To use the Temp Sensor: 1. Set the input for ADC to the temperature sensor, "Register 0Fh. ADC Configuration"—adcsel[2:0] = 000 2. Set the reference for ADC, "Register 0Fh. ADC Configuration"—adcref[1:0] = 00 3. Set the temperature range for ADC, "Register 12h. Temperature Sensor Calibration"—tsrange[1:0] 4. Set entsoffs = 1, "Register 12h. Temperature Sensor Calibration" 5. Trigger ADC reading, "Register 0Fh. ADC Configuration"—adcstart = 1 6. Read temperature value—Read contents of "Register 11h. ADC Value" Add R/W Function/Description 12 R/W Temperature Sensor Control 13 R/W Temperature Value Offset D7 D6 D5 D4 D3 D2 tsrange[1] tsrange[0] entsoffs entstrim tstrim[3] tstrim[2] tvoffs[7] tvoffs[6] tvoffs[5] tvoffs[4] tvoffs[3] tvoffs[2] D1 D0 POR Def. vbgtrim[1] vbgtrim[0] tvoffs[1] tvoffs[0] 20h 00h Table 14. Temperature Sensor Range entoff tsrange[1] tsrange[0] Temp. range Unit Slope ADC8 LSB 1 0 0 –64 … 64 °C 8 mV/°C 0.5 °C 1 0 1 –64 … 192 °C 4 mV/°C 1 °C 1 1 0 0 … 128 °C 8 mV/°C 0.5 °C 1 1 1 –40 … 216 °F 4 mV/°F 1 °F 0* 1 0 0 … 341 °K 3 mV/°K 1.333 °K *Note: Absolute temperature mode, no temperature shift. This mode is only for test purposes. POR value of EN_TOFF is 1. The slope of the temperature sensor is very linear and monotonic. For absolute accuracy better than 10 °C calibration is necessary. The temperature sensor may be calibrated by setting entsoffs = 1 in “Register 12h. Temperature Sensor Control” and setting the offset with the tvoffs[7:0] bits in “Register 13h. Temperature Value Offset.” This method adds a positive offset digitally to the ADC value that is read in “Register 11h. ADC Value.” The other method of calibration is to use the tstrim which compensates the analog circuit. This is done by setting entstrim = 1 and using the tstrim[2:0] bits to offset the temperature in “Register 12h. Temperature Sensor Control.” With this method of calibration, a negative offset may be achieved. With both methods of calibration better than ±3 °C absolute accuracy may be achieved. The different ranges for the temperature sensor and ADC8 are demonstrated in Figure 18. The value of the ADC8 may be translated to a temperature reading by ADC8Value x ADC8 LSB + Lowest Temperature in Temp Range. For instance for a tsrange = 00, Temp = ADC8Value x 0.5 – 64. 38 Tel: +86-755-82973805 Fax: +86-755-82973550 E-mail: [email protected] http://www.hoperf.com RFM42B/43B Temperature Measurement with ADC8 300 250 ADC Value 200 Sensor Range 0 Sensor Range 1 150 Sensor Range 2 Sensor Range 3 100 50 0 -40 -20 0 20 40 60 80 100 Temperature [Celsius] Figure 18. Temperature Ranges using ADC8 Tel: +86-755-82973805 Fax: +86-755-82973550 E-mail: [email protected] http://www.hoperf.com 39 RFM42B/43B 7.5. Low Battery Detector A low battery detector (LBD) with digital read-out is integrated into the chip. A digital threshold may be programmed into the lbdt[4:0] field in "Register 1Ah. Low Battery Detector Threshold." When the digitized battery voltage reaches this threshold an interrupt will be generated on the nIRQ pin to the microcontroller. The microcontroller can confirm source of the interrupt by reading "Register 03h. Interrupt/Status 1" and “Register 04h. Interrupt/Status 2,” If the LBD is enabled while the chip is in SLEEP mode, it will automatically enable the RC oscillator which will periodically turn on the LBD circuit to measure the battery voltage. The battery voltage may also be read out through "Register 1Bh. Battery Voltage Level" at any time when the LBD is enabled. The low battery detect function is enabled by setting enlbd=1 in "Register 07h. Operating Mode and Function Control 1". Ad R/W Function/Description 1A R/W Low Battery Detector Threshold 1B R Battery Voltage Level D7 0 D6 0 D5 0 D4 D3 D2 D1 D0 POR Def. lbdt[4] lbdt[3] lbdt[2] lbdt[1] lbdt[0] 14h vbat[4] vbat[3] vbat[2] vbat[1] vbat[0] — The LBD output is digitized by a 5-bit ADC. When the LBD function is enabled, enlbd = 1 in "Register 07h. Operating Mode and Function Control 1", the battery voltage may be read at anytime by reading "Register 1Bh. Battery Voltage Level." A battery voltage threshold may be programmed in “Register 1Ah. Low Battery Detector Threshold." When the battery voltage level drops below the battery voltage threshold an interrupt will be generated on the nIRQ pin to the microcontroller if the LBD interrupt is enabled in “Register 06h. Interrupt Enable 2,” The microcontroller will then need to verify the interrupt by reading the interrupt status register, addresses 03 and 04h. The LSB step size for the LBD ADC is 50 mV, with the ADC range demonstrated in the table below. If the LBD is enabled the LBD and ADC will automatically be enabled every 1 s for approximately 250 µs to measure the voltage which minimizes the current consumption in Sensor mode. Before an interrupt is activated four consecutive readings are required. BatteryVoltage 1.7 50mV ADCValue 40 Tel: +86-755-82973805 ADC Value VDD Voltage [V] 0 < 1.7 1 1.7–1.75 2 1.75–1.8 … … 29 3.1–3.15 30 3.15–3.2 31 > 3.2 Fax: +86-755-82973550 E-mail: [email protected] http://www.hoperf.com RFM42B/43B 7.6. Wake-Up Timer The chip contains an integrated wake-up timer which can be used to periodically wake the chip from SLEEP mode. The wake-up timer runs from the internal 32.768 kHz RC Oscillator. The wake-up timer can be configured to run when in SLEEP mode. If enwt = 1 in "Register 07h. Operating Mode and Function Control 1" when entering SLEEP mode, the wake-up timer will count for a time specified defined in Registers 14–16h, "Wake Up Timer Period." At the expiration of this period an interrupt will be generated on the nIRQ pin if this interrupt is enabled. The microcontroller will then need to verify the interrupt by reading the Registers 03h–04h, "Interrupt Status 1 & 2". The wake-up timer value may be read at any time by the wtv[15:0] read only registers 13h–14h. The formula for calculating the Wake-Up Period is the following: WUT 4 M 2R ms 32 . 768 WUT Register Description wtr[3:0] R Value in Formula wtd[1:0] D Value in Formula wtm[15:0] M Value in Formula Use of the D variable in the formula is only necessary if finer resolution is required than can be achieved by using the R value. Add R/W Function/Description D7 D6 D5 D4 D3 D2 D1 D0 POR Def. wtr[3] wtr[2] wtr[1] wtr[0] wtd[1] wtd[0] 00h 14 R/W Wake-Up Timer Period 1 15 R/W Wake-Up Timer Period 2 wtm[15] wtm[14] wtm[13] wtm[12] wtm[11] wtm[10] wtm[9] wtm[8] 00h 16 R/W Wake-Up Timer Period 3 wtm[7] wtm[6] wtm[5] wtm[4] wtm[3] wtm[2] wtm[1] wtm[0] 00h 17 R Wake-Up Timer Value 1 wtv[15] wtv[14] wtv[13] wtv[12] wtv[11] wtv[10] wtv[9] wtv[8] — 18 R Wake-Up Timer Value 2 wtv[7] wtv[6] wtv[5] wtv[4] wtv[3] wtv[2] wtv[1] wtv[0] — There are two different methods for utilizing the wake-up timer (WUT) depending on if the WUT interrupt is enabled in “Register 06h. Interrupt Enable 2,”. If the WUT interrupt is enabled then nIRQ pin will go low when the timer expires. The chip will also change state so that the 30 MHz XTAL is enabled so that the microcontroller clock output is available for the microcontroller to use to process the interrupt. The other method of use is to not enable the WUT interrupt and use the WUT GPIO setting. In this mode of operation the chip will not change state until commanded by the microcontroller. The different modes of operating the WUT and the current consumption impacts are demonstrated in Figure 19. A 32 kHz XTAL may also be used for better timing accuracy. By setting the x32 ksel bit in “Register 07h. Operating & Function Control 1," GPIO0 is automatically reconfigured so that an external 32 kHz XTAL may be connected to this pin. In this mode, the GPIO0 is extremely sensitive to parasitic capacitance, so only the XTAL should be connected to this pin with the XTAL physically located as close to the pin as possible. Once the x32 ksel bit is set, all internal functions such as WUT, microcontroller clock, and LDC mode will use the 32 kHz XTAL and not the 32 kHz RC oscillator. Tel: +86-755-82973805 Fax: +86-755-82973550 E-mail: [email protected] http://www.hoperf.com 41 RFM42B/43B Interrupt Enable enwut =1 ( Reg 06h) WUT Period GPIOX =00001 nIRQ SPI Interrupt Read Chip State Sleep Current Consumption Ready Sleep Ready 1.5 mA Sleep 1.5 mA Sleep 1.5 mA 1 uA 1 uA Ready 1 uA Interrupt Enable enwut =0 ( Reg 06h) WUT Period GPIOX =00001 nIRQ SPI Interrupt Read Chip State Sleep Current Consumption 1 uA Figure 19. WUT Interrupt and WUT Operation 42 Tel: +86-755-82973805 Fax: +86-755-82973550 E-mail: [email protected] http://www.hoperf.com RFM42B/43B 7.7. GPIO Configuration Three general purpose IOs (GPIOs) are available. Numerous functions such as specific interrupts, TRSW control, Microcontroller Output, etc. can be routed to the GPIO pins as shown in the tables below. When in Shutdown mode all the GPIO pads are pulled low. Note: The ADC should not be selected as an input to the GPIO in Standby or Sleep Modes and will cause excess current consumption. Add R/W Function/ Description D7 D6 D5 D4 D3 D2 D1 D0 POR Def. 0B R/W GPIO0 Configuration gpio0drv[1] gpio0drv[0] pup0 gpio0[4] gpio0[3] gpio0[2] gpio0[1] gpio0[0] 00h 0C R/W GPIO1 Configuration gpio1drv[1] gpio1drv[0] pup1 gpio1[4] gpio1[3] gpio1[2] gpio1[1] gpio1[0] 00h 0D R/W GPIO2 Configuration gpio2drv[1] gpio2drv[0] pup2 gpio2[4] gpio2[3] gpio2[2] gpio2[1] gpio2[0] 00h 0E R/W I/O Port Configuration extitst[2] extitst[1] extitst[0] itsdo dio2 dio1 dio0 00h The GPIO settings for GPIO1 and GPIO2 are the same as for GPIO0 with the exception of the 00000 default setting. The default settings for each GPIO are listed below: GPIO 00000—Default Setting GPIO0 POR GPIO1 POR Inverted GPIO2 Microcontroller Clock For a complete list of the available GPIO's see “ RFM42B/43B Register Descriptions.” The GPIO drive strength may be adjusted with the gpioXdrv[1:0] bits. Setting a higher value will increase the drive strength and current capability of the GPIO by changing the driver size. Special care should be taken in setting the drive strength and loading on GPIO2 when the microcontroller clock is used. Excess loading or inadequate drive may contribute to increased spurious emissions. Tel: +86-755-82973805 Fax: +86-755-82973550 E-mail: [email protected] http://www.hoperf.com 43 RFM42B/43B 8. Reference Design Freq. band RDC LC C0 L0 CM LM CM2 LM2 CM3 [MHz] [Ohm] [nH] [pF] [nH] [pF] [nH] [pF] [nH] [pF] Figure 20A.RFM42B Reference Design Schematic Figure 20B.RFM43B Reference Design Schematic 44 Tel: +86-755-82973805 Fax: +86-755-82973550 E-mail: [email protected] http://www.hoperf.com RFM42B/43B 9. Register Table and Descriptions Table 15. Register Descriptions Add R/W Function/Desc D7 0 ffovfl ifferr Reserved enfferr Reserved swres Reserved xtalshft D6 0 ffunfl itxffafull Reserved entxffafull Reserved enlbd Reserved xlc[6] Reserved gpio0drv[1] gpio1drv[1] gpio2drv[1] Reserved adcstart/adcdone Reserved adc[7] tsrange[1] tvoffs[7] Reserved wtm[15] wtm[7] wtv[15] wtv[7] Reserved gpio0drv[0] gpio1drv[0] gpio2drv[0] extitst[2] adcsel[2] R/W Low Battery Detector Threshold R Battery Voltage Level Reserved 0 Reserved 0 R/W R Data Access Control EzMAC status Reserved 0 lsbfrst Reserved R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W Header Control 2 Preamble Length Sync Word 3 Sync Word 2 Sync Word 1 Sync Word 0 Transmit Header 3 Transmit Header 2 Transmit Header 1 Transmit Header 0 Transmit Packet Length ADC8 Control Reserved prealen[7] sync[31] sync[23] sync[15] sync[7] txhd[31] txhd[23] txhd[15] txhd[7] pklen[7] Reserved hdlen[2] prealen[6] sync[30] sync[22] sync[14] sync[6] txhd[30] txhd[22] txhd[14] txhd[6] pklen[6] Reserved R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W pwst[2] papeakval txdr[15] txdr[7] Reserved trclk[1] fd[7] fo[7] Reserved Reserved fc[15] fc[7] fhch[7] pwst[1] papeaken txdr[14] txdr[6] Reserved trclk[0] fd[6] fo[6] Reserved sbsel fc[14] fc[6] fhch[6] fhs[7] Reserved Reserved fhs[6] Reserved Reserved fifod[7] fifod[6] 01 02 03 04 05 06 07 08 09 R R R R R/W R/W R/W R/W R/W 0A 0B 0C 0D 0E 0F R/W R/W R/W R/W R/W R/W Device Version Device Status Interrupt Status 1 Interrupt Status 2 Interrupt Enable 1 Interrupt Enable 2 Operating & Function Control 1 Operating & Function Control 2 Crystal Oscillator Load Capacitance Microcontroller Output Clock GPIO0 Configuration GPIO1 Configuration GPIO2 Configuration I/O Port Configuration ADC Configuration 10 11 12 13 14 15 16 17 18 19 1A 1B 1C-2F 30 31 32 33 34 36 37 38 39 3A 3B 3C 3D 3E 4F 60 62 6D 6E 6F 70 71 72 73 74 75 76 77 79 R/W R R/W R/W R/W R/W R/W R R ADC Sensor Amplifier Offset ADC Value Temperature Sensor Control Temperature Value Offset Wake-Up Timer Period 1 Wake-Up Timer Period 2 Wake-Up Timer Period 3 Wake-Up Timer Value 1 Wake-Up Timer Value 2 7A 7C 7D 7E 7F R/W R/W R/W Crystal Oscillator/Control Test TX Power TX Data Rate 1 TX Data Rate 0 Modulation Mode Control 1 Modulation Mode Control 2 Frequency Deviation Frequency Offset 1 Frequency Offset 2 Frequency Band Select Nominal Carrier Frequency 1 Nominal Carrier Frequency 0 Frequency Hopping Channel Select Frequency Hopping Step Size TX FIFO Control 1 TX FIFO Control 2 R/W FIFO Access Reserved adc[6] tsrange[0] tvoffs[6] Reserved wtm[14] wtm[6] wtv[14] wtv[6] itxffaem Reserved entxffaem Reserved enwt Reserved xlc[5] Data D4 vc[4] Reserved Reserved Reserved Reserved Reserved x32ksel Reserved xlc[4] D3 vc[3] reserved iext iwut enext enwut txon autotx xlc[3] D2 vc[2] reserved ipksent ilbd enpksent enlbd Reserved enldm xlc[2] D1 vc[1] cps[1] Reserved ichiprdy Reserved enchiprdy pllon Reserved xlc[1] D0 vc[0] cps[0] Reserved ipor Reserved enpor xton ffclrtx xlc[0] POR Default 06h — — — 00h 03h 01h 00h 7Fh clkt[1] pup0 pup1 pup2 extitst[1] adcsel[1] clkt[0] gpio0[4] gpio1[4] gpio2[4] extitst[0] adcsel[0] enlfc gpio0[3] gpio1[3] gpio2[3] itsdo adcref[1] mclk[2] gpio0[2] gpio1[2] gpio2[2] dio2 adcref[0] mclk[1] gpio0[1] gpio1[1] gpio2[1] dio1 adcgain[1] mclk[0] gpio0[0] gpio1[0] gpio2[0] dio0 adcgain[0] 06h 00h 00h 00h 00h 00h adcoffs[3] adc[3] tstrim[3] tvoffs[3] wtr[3] wtm[11] wtm[3] wtv[11] wtv[3] adcoffs[2] adc[2] tstrim[2] tvoffs[2] wtr[2] wtm[10] wtm[2] wtv[10] wtv[2] adcoffs[1] adc[1] tstrim[1] tvoffs[1] wtr[1] wtm[9] wtm[1] wtv[9] wtv[1] adcoffs[0] adc[0] tstrim[0] tvoffs[0] wtr[0] wtm[8] wtm[0] wtv[8] wtv[0] 00h — 20h 00h 03h 00h 01h — — lbdt[3] vbat[3] lbdt[2] vbat[2] lbdt[1] vbat[1] lbdt[0] vbat[0] 14h — enpactx Reserved encrc Reserved crc[1] pktx crc[0] pksent 8Dh — fixpklen prealen[3] sync[27] sync[19] sync[11] sync[3] txhd[27] txhd[19] txhd[11] txhd[3] pklen[3] adc8[3] synclen[1] prealen[2] sync[26] sync[18] sync[10] sync[2] txhd[26] txhd[18] txhd[10] txhd[2] pklen[2] adc8[2] synclen[0] prealen[1] sync[25] sync[17] sync[9] sync[1] txhd[25] txhd[17] txhd[9] txhd[1] pklen[1] adc8[1] prealen[8] prealen[0] sync[24] sync[16] sync[8] sync[0] txhd[24] txhd[16] txhd[8] txhd[0] pklen[0] adc8[0] 22h 08h 2Dh D4h 00h 00h 00h 00h 00h 00h 00h 10h enbias2x Ina_sw txdr[11] txdr[3] manppol eninv fd[3] fo[3] Reserved fb[3] fc[11] fc[3] fhch[3] enamp2x txpow[2] txdr[10] txdr[2] enmaninv fd[8] fd[2] fo[2] Reserved fb[2] fc[10] fc[2] fhch[2] bufovr txpow[1] txdr[9] txdr[1] enmanch modtyp[1] fd[1] fo[1] fo[9] fb[1] fc[9] fc[1] fhch[1] enbuf txpow[0] txdr[8] txdr[0] enwhite modtyp[0] fd[0] fo[0] fo[8] fb[0] fc[8] fc[0] fhch[0] 24h 18h 0Ah 3Dh 0Ch 00h 20h 00h 00h 75h BBh 80h 00h fhs[3] txafthr[3] txaethr[3] fhs[2] txafthr[2] txaethr[2] fhs[1] txafthr[1] txaethr[1] fhs[0] txafthr[0] txaethr[0] 00h 37h 04h fifod[3] fifod[2] fifod[1] fifod[0] — D5 0 Reserved Reserved adc[5] adc[4] entsoffs entstrim tvoffs[5] tvoffs[4] Reserved wtr[4] wtm[13] wtm[12] wtm[5] wtm[4] wtv[13] wtv[12] wtv[5] wtv[4] Reserved Reserved lbdt[4] 0 vbat[4] Reserved crcdonly Reserved Reserved Reserved Reserved hdlen[1] hdlen[0] prealen[5] prealen[4] sync[29] sync[28] sync[21] sync[20] sync[13] sync[12] sync[5] sync[4] txhd[29] txhd[28] txhd[21] txhd[20] txhd[13] txhd[12] txhd[5] txhd[4] pklen[5] pklen[4] adc8[5] adc8[4] Reserved pwst[0] clkhyst papeaklvl[1] papeaklvl[0] txdr[13] txdr[12] txdr[5] txdr[4] txdtrtscale enphpwdn dtmod[1] dtmod[0] fd[5] fd[4] fo[5] fo[4] Reserved Reserved hbsel fb[4] fc[13] fc[12] fc[5] fc[4] fhch[5] fhch[4] fhs[5] fhs[4] txafthr[5] txafthr[4] txaethr[5] txaethr[4] Reserved fifod[5] fifod[4] Note: Detailed register descriptions are available in “RFM42B/43B Register Descriptions.” 45 Tel: +86-755-82973805 Fax: +86-755-82973550 E-mail: [email protected] http://www.hoperf.com RFM42B/43B 10. Pin Descriptions: RFM42B/43B RFM42B/43B-S1 RFM42B/43B-S2 RFM42B/43B-D Tel: +86-755-82973805 Fax: +86-755-82973550 E-mail: [email protected] http://www.hoperf.com 46 RFM42B/43B VCC S +1.8 to +3.6 V supply voltage. The recommended VCC supply voltage is +3.3 V. GND S Ground reference. GPIO_0 I/O GPIO_1 I/O GPIO_2 I/O SDO O General Purpose Digital I/O that may be configured through the registers to perform various functions including: Microcontroller Clock Output, FIFO status, POR, Wake-Up timer, Low Battery Detect, TRSW, AntDiversity control, etc. See the SPI GPIO Configuration Registers, Address 0Bh, 0Ch, and 0Dh for more information. 0–VCC V digital output that provides a serial readback function of the internal control registers. Serial Data input. 0–VCC V digital input. This pin provides the serial data stream for the 4-line SDI I serial data bus. Serial Clock input. 0–VDD V digital input. This pin provides the serial data clock function for SCLK I the 4-line serial data bus. Data is clocked into the RFM42/43 on positive edge transitions. Serial Interface Select input. 0– VCC V digital input. This pin provides the Select/Enable nSEL I function for the 4-line serial data bus. The signal is also used to signify burst read/write mode. General Microcontroller Interrupt Status output. When the RFM42/43 exhibits anyone of the Interrupt Events the nIRQ pin will be set low=0. Please see the Control Logic registers nIRQ O section for more information on the Interrupt Events. The Microcontroller can then determine the state of the interrupt by reading a corresponding SPI Interrupt Status Registers, Address 03h and 04h. I SDN Shutdown input pin. 0–VCC V digital input. SDN should be = 0 in all modes except Shutdown mode. When SDN =1 the chip will be completely shutdown and the contents of the registers will be lost. ANT NC 47 Tel: +86-755-82973805 I/O RF signal output/input.(50 OHM output /input Impedance) No Connection Fax: +86-755-82973550 E-mail: [email protected] http://www.hoperf.com RFM42B/43B 12. Mechanical Dimension:RFM42B/43B SMD PACKAGE（S1） SMD PACKAGE（S2） Tel: +86-755-82973805 Fax: +86-755-82973550 E-mail: [email protected] http://www.hoperf.com 48 RFM42B/43B DIP PACKAGE（D） 49 Tel: +86-755-82973805 Fax: +86-755-82973550 E-mail: [email protected] http://www.hoperf.com RFM42B/43B 13. Ordering Information Part Number=module type—operation band—package type RFM42B/43B—433—D module type operation band Package example：1，RFM43B module at 433MHz band, DIP : RFM43B-433-D。 2，RFM42B module at 868MHZ band, SMD, thickness at 4.9mm: RFM42B-868-S1。 Tel: +86-755-82973805 Fax: +86-755-82973550 E-mail: [email protected] http://www.hoperf.com 50 RFM42B/43B This document may contain preliminary information and is subject to change by Hope Microelectronics without notice. Hope Microelectronics assumes no HOPE MICROELECTRONICS CO.,LTD Add:4/F, Block B3, East Industrial responsibility or liability for any use of the information contained herein. Nothing Area, in this document shall operate as an express or implied license or indemnity Huaqiaocheng, Shenzhen, Guangdong, China under the intellectual property rights of Hope Microelectronics or third parties. Tel: The products described in this document are not intended for use in 86-755-82973805 Fax: 86-755-82973550 Email: implantation or other direct life support applications where malfunction may [email protected] result in the direct physical harm or injury to persons. NO WARRANTIES OF [email protected] ANY KIND, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES Website: http://www.hoperf.com http://hoperf.en.alibaba.com OF MECHANTABILITY OR FITNESS FOR A ARTICULAR PURPOSE, ARE OFFERED IN THIS DOCUMENT. ©2006, HOPE MICROELECTRONICS CO.,LTD. All rights reserved. Tel: +86-755-82973805 51 Fax: +86-755-82973550 E-ma il: [email protected] ht tp://www.hoperf.com