DATASHEET AX8052F131 SoC Ultra-Low Power RFMicrocontroller for the 400470 MHz and 800-940 MHz bands Revision 2 2 Table of Contents 1. Overview .................................................................................................................. 5 1.1. Features .................................................................................................................... 5 1.2. Applications ............................................................................................................... 6 2. Block Diagram .......................................................................................................... 7 3. Pin Function Descriptions ......................................................................................... 8 3.1. Alternate Pin Functions ................................................................................................ 9 3.2. Pinout Drawing .......................................................................................................... 10 4. Specifications ......................................................................................................... 11 4.1. Absolute Maximum Ratings ......................................................................................... 11 4.2. DC Characteristics ..................................................................................................... 12 Supplies .................................................................................................................... 12 Logic ........................................................................................................................ 14 4.3. AC Characteristics ...................................................................................................... 15 Crystal Oscillator (RF reference oscillator) ..................................................................... 15 RF Frequency Generation Subsystem (Synthesizer) ........................................................ 16 Transmitter ............................................................................................................... 18 Low Frequency Crystal Oscillator .................................................................................. 19 Internal Low Power Oscillator ...................................................................................... 19 Internal RC Oscillator.................................................................................................. 19 Microcontroller ........................................................................................................... 20 ADC / Comparator / Temperature Sensor ...................................................................... 21 5. Circuit Description.................................................................................................. 22 5.1. Microcontroller .......................................................................................................... 23 Memory Architecture .................................................................................................. 23 Memory Map.............................................................................................................. 24 Power Management .................................................................................................... 25 Clocking .................................................................................................................... 26 Reset and Interrupts .................................................................................................. 27 www.onsemi.com AX8052F131 Table of Contents Debugging ................................................................................................................ 27 5.2. Timer, Output Compare and Input Capture ................................................................... 28 5.3. UART ....................................................................................................................... 28 5.4. SPI Master/Slave Controller ........................................................................................ 28 5.5. ADC, Analog Comparators and Temperature Sensor ....................................................... 29 5.6. DMA Controller .......................................................................................................... 30 5.7. AES Engine ............................................................................................................... 30 5.8. Crystal Oscillator (RF reference oscillator) ..................................................................... 30 5.9. SYSCLK Output.......................................................................................................... 31 5.10. Power-on-reset (POR) and RESET_N Input ............................................................... 31 5.11. Ports ................................................................................................................... 32 6. Transmitter ............................................................................................................ 33 6.1. RF Frequency Generation Subsystem ........................................................................... 33 VCO ......................................................................................................................... 33 VCO Auto-Ranging ..................................................................................................... 33 Loop Filter and Charge Pump ....................................................................................... 34 Registers................................................................................................................... 34 6.2. RF Input and Output Stage (ANTP/ANTN) ..................................................................... 35 6.3. Encoder .................................................................................................................... 35 6.4. Framing and FIFO ...................................................................................................... 36 HDLC Mode ............................................................................................................... 37 RAW Mode ................................................................................................................ 37 802.15.4 (ZigBee) DSSS ............................................................................................. 37 6.5. Modulator ................................................................................................................. 38 6.6. PWRMODE Register .................................................................................................... 39 7. Application Information ......................................................................................... 40 Connecting to Debug Adapter ...................................................................................... 40 7.1. Antenna Interface Circuitry ......................................................................................... 41 Single-Ended Antenna Interface ................................................................................... 41 8. QFN40 Package Information .................................................................................. 42 www.onsemi.com AX8052F131 3 4 Overview 8.1. Package Outline QFN40 .............................................................................................. 42 8.2. QFN40 Soldering Profile .............................................................................................. 43 8.3. QFN40 Recommended Pad Layout ................................................................................ 44 8.4. Assembly Process ...................................................................................................... 44 Stencil Design & Solder Paste Application ...................................................................... 44 9. Device Versions ...................................................................................................... 46 www.onsemi.com AX8052F131 Overview 1. Overview o 2 output compares with PWM capability o 10-bit 500 ksample/s analogto-digital converter o Temperature sensor o 2 analog comparators o 2 UARTs o 1 general purpose master/slave SPI o 2 channel DMA controller o Multi-megabit/s AES encryption/decryption engine with True Random Number Generator (TRNG), supports AES-128, AES-192 and AES256 1 o Ultra-low power 10 kHz/640 Hz wakeup oscillator, with automatic calibration against a precise clock o Internal 20 MHz RC oscillator, with automatic calibration against a precise clock for flexible system clocking o Low frequency tuning fork crystal oscillator for accurate low power time keeping o Brown-out and power-onreset detection 1.1. Features SoC Ultra-low power RF-microcontroller for wireless communication applications • QFN40 package • Supply range 2.2V - 3.6V (1.8V MCU) • -40°C to 85°C • Ultra-low power consumption: • o CPU active mode 150 μA/MHz o Sleep mode with 256 Byte RAM retention and wake-up timer running 900 nA o Sleep mode 4 kByte RAM retention and wake-up timer running 1.9 μA o Sleep mode 8 kByte RAM retention and wake-up timer running 2.6 μA o Radio TX-mode 22 mA at 10 dBm output power AX8052 features o Ultra-low power MCU core compatible with industry standard 8052 instruction set o Down to 250 nA wake-up current o 1 cycle/instruction for many instructions o 64 kByte in-system programmable FLASH o Code protection lock o 8.25 kByte SRAM o 3-wire (1 dedicated, 2 shared) in-circuit debug interface o 3 16-bit timers with Σ∆ output capability o 2 16-bit wakeup timers o 2 input captures • High-performance RF transmitter compatible to AX5031 o 400-470 MHz and 800-940 MHz SRD bands o -5 dBm to +15 dBm programmable output o 13 mA @ 0 dBm, 868 MHz o 22 mA @ 10 dBm, 868 MHz o 44 mA @ 15 dBm, 868 MHz o Wide variety of shaped modulations supported (ASK, 1 The AES engine and the TRNG require software enabling and support. www.onsemi.com AX8052F131 5 6 Overview PSK, OQPSK, MSK, FSK, GFSK, 4-FSK) o Flexible shaping for the modulations o Data rates 1 to 350 kbps for FSK, MSK 1 to 2000 kbps for ASK 10 to 2000 kbps for PSK o Fully integrated RF frequency synthesizer with ultra-fast settling time for low-power consumption o RF carrier frequency and FSK deviation programmable in 1 Hz steps o 802.15.4 compatible o Few external components o Channel hopping up to 2000 hops/s o Up to +16 dBm at 433 MHz programmable transmitter power amplifier for long range operation o Crystal oscillator with programmable transconductance and programmable internal tuning capacitors for low cost crystals o Differential antenna pins o Dual frequency registers o Internally generated coding for forward Viterbi error correction o Software compatible to AX5031 1.2. Applications 400-470 MHz and 800-940 MHz data transmission in the Short Range Devices (SRD) band. • Automatic meter reading Wireless networks • Remote keyless entry • Suited for systems targeting compliance to EN 300 220 wide band, FCC part 15.247 and FCC part 15.249 • • Access control • Suited for systems targeting compliance with Wireless M-Bus S/T Mode • Garage door openers • 802.15.4 compatible Home automation • • Pointing devices and keyboards • Telemetric applications, sensor readout • Toys Active RFID • • Wireless audio • Automatic meter reading www.onsemi.com AX8052F131 Block Diagram 2. Block Diagram AX8052F131 VDDA Crystal Oscillator typ. 16MHz FOUT FXTAL CLK16N VREG Voltage Regulator RF Frequency Generation Subsystem FIFO Modulator PA Framing CLK16P Encoder ANTP ANTN Communication Controller & Radio Interface Controller Radio configuration Divider POR FLASH 64k GPIO DMA Controller Timer Counter 0 8k 256 Axsem 8052 Timer Counter 2 DBG_EN Debug Interface Output Compare0 RESET_N GND VDD_IO System Controller wakeup oscillator RC Oscillator tuning fork crystal oscillator PA0 PA1 PA2 PA3 PA4 PA5 PA6 PA7 Timer Counter 1 I-Bus IRQ Req RAM DMA Req SYSCLK PB0 PB1 PB2 PB3 PB4 PB5 PB6 PB7 Output Compare 1 wakeup timer 2x Input Capture 0 Reset, Clocks, Power AES Crypto Engine PC0 PC1 PC2 PC3 Input Capture 1 ADC Comparators Temp Sensor UART 0 SFR-Bus X-Bus P-Bus SPI master/slave UART 1 I/O Multiplexer Figure 1 Functional block diagram of the AX8052F131 www.onsemi.com AX8052F131 7 8 Pin Function Descriptions 3. Pin Function Descriptions Symbol Pin(s) Type Description CLK16P 1 A Crystal oscillator input/output (RF reference) CLK16N 2 A Crystal oscillator input/output (RF reference) VDDA 3 P Power supply, must be supplied with regulated voltage VREG GND 4 P Ground ANTP 5 A Antenna output ANTN 6 A Antenna output GND 7 P Ground VDDA 8 P Power supply, must be supplied with regulated voltage VREG SYSCLK 9 I/O/PU Must be connected to SYSCLK at pin 13 T1 10 I/O/PU Must be connected to T1 at pin 12 T2 11 I/O/PU Must be left unconnected T1 12 I/O/PU Must be connected to T1 at pin 10 SYSCLK 13 I/O/PU Must be connected to SYSCLK at pin 9 PC3 14 I/O/PU General Purpose IO PC2 15 I/O/PU General Purpose IO PC1 16 I/O/PU General Purpose IO PC0 17 I/O/PU General Purpose IO PB0 18 I/O/PU General Purpose IO PB1 19 I/O/PU General Purpose IO PB2 20 I/O/PU General Purpose IO PB3 21 I/O/PU General Purpose IO PB4 22 I/O/PU General Purpose IO PB5 23 I/O/PU General Purpose IO PB6 24 I/O/PU General Purpose IO, DBG_DATA PB7 25 I/O/PU General Purpose IO, DBG_CLK DBG_EN 26 I/PD In-Circuit Debugger Enable RESET_N 27 I/PU Optional reset pin If this pin is not used it must be connected to VDD_IO GND 28 P Ground VDD_IO 29 P Unregulated power supply (battery input) PA0 30 I/O/A/PU General Purpose IO PA1 31 I/O/A/PU General Purpose IO PA2 32 I/O/A/PU General Purpose IO PA3 33 I/O/A/PU General Purpose IO PA4 34 I/O/A/PU General Purpose IO PA5 35 I/O/A/PU General Purpose IO PA6 36 I/O/A/PU General Purpose IO PA7 37 I/O/A/PU General Purpose IO www.onsemi.com AX8052F131 Pin Function Descriptions Symbol Pin(s) Type PC7 38 I/O/PU VREG 39 P Regulated output voltage VDDA pins must be connected to this supply voltage A 1µF low ESR capacitor to GND must be connected to this pin GND 40 P Ground GND Center pad P Ground on center pad of QFN, must be connected A = I = O = PU = Description General Purpose IO analog signal digital input signal digital output signal pull-up I/O N P PD = = = = digital input/output signal not to be connected power or ground pull-down All digital inputs are Schmitt trigger inputs, digital input and output levels are LVCMOS/LVTTL compatible. Port A Pins (PA0 - PA7) must not be driven above VDD_IO, all other digital inputs are 5V tolerant. Pull-ups are programmable for all GPIO pins. 3.1. Alternate Pin Functions GPIO Pins are shared with dedicated Input/Output signals of on-chip peripherals. The following table lists the available functions on each GPIO pin. GPIO Alternate Functions PA0 T0OUT IC1 ADC0 PA1 T0CLK OC1 ADC1 PA2 OC0 U1RX ADC2 COMPI00 PA3 T1OUT ADC3 LPXTALP PA4 T1CLK COMPO0 ADC4 LPXTALN PA5 IC0 U1TX ADC5 COMPI10 PA6 T2OUT ADCTRIG ADC6 COMPI01 PA7 T2CLK COMPO1 ADC7 COMPI11 PB0 U1TX IC1 EXTIRQ0 PB1 U1RX OC1 PB2 IC0 T2OUT PB3 OC0 T2CLK PB4 U0TX T1CLK PB5 U0RX T1OUT PB6 DBG_DATA PB7 DBG_CLK PC0 SSEL T0OUT EXTIRQ0 PC1 SSCK T0CLK COMPO1 PC2 SMOSI U0TX PC3 SMISO U0RX PC7 RPWRUP www.onsemi.com EXTIRQ1 DSWAKE COMPO0 AX8052F131 9 T1 SYSCLK 16 17 18 19 20 T2OUT/IC0/PB2 T2 15 OC1/U1RX/PB1 T1 14 EXTIRQ0/IC1/U1TX/PB0 13 EXTIRQ0/T0OUT/SSEL/PC0 12 COMPO1/T0CLK/SSCK/PC1 11 U0TX/SMOSI/PC2 10 COMPO0/U0RX/SMISO/PC3 9 SYSCLK GND VREG PC7/RPWRUP PA7/ADC7/T2CLK/COMPO1/COMPI11 PA6/ADC6/T2OUT/ADCTRIG/COMPI01 PA5/ADC5/IC0/U1TX/COMPI10 PA4/ADC4/T1CLK/COMPO0/LPXTALN PA3/ADC3/T1OUT/LPXTALP PA2/ADC2/OC0/U1RX/COMPI00 PA1/ADC1/T0CLK/OC1 PA0/ADC0/T0OUT/IC1 VDD_IO 10 Pin Function Descriptions 3.2. Pinout Drawing 40 39 38 37 36 35 34 33 32 31 30 29 CLK16P 1 28 GND CLK16N 2 27 RESET_N VDDA 3 26 DBG_EN GND 4 25 PB7/DBG_CLK ANTP 5 24 PB6/DBG_DATA ANTN 6 23 PB5/U0RX/T1OUT GND 7 22 PB4/U0TX/T1CLK VDDA 8 21 PB3/OC0/T2CLK/EXTIRQ1/DSWAKE AX8052F131 QFN40 Figure 2 Pinout drawing (Top view) www.onsemi.com AX8052F131 Specifications 4. Specifications 4.1. Absolute Maximum Ratings Stresses above those listed under Absolute Maximum Ratings may cause permanent damage to the device. This is a stress rating only; functional operation of the device at these or any other conditions above those listed in the operational sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. SYMBOL DESCRIPTION VDD_IO Supply voltage CONDITION MIN MAX UNIT -0.5 5.5 V IDD Supply current 100 mA Ptot Total power consumption 800 mW II1 DC current into any pin except ANTP, ANTN -10 10 mA II2 DC current into pins ANTP, ANTN -100 100 mA IO Output Current 40 mA Via Input voltage ANTP, ANTN pins -0.5 5.5 V Input voltage digital pins -0.5 5.5 V -2000 2000 V Ves Electrostatic handling HBM Tamb Operating temperature -40 85 °C Tstg Storage temperature -65 150 °C Tj Junction Temperature 150 °C www.onsemi.com AX8052F131 11 12 Specifications 4.2. DC Characteristics Supplies SYMBOL DESCRIPTION TAMB Operational ambient temperature CONDITION MIN TYP MAX UNIT -40 27 85 °C TX operation 2.2 3.0 3.6 V Transmitter switched off 1.8 3.0 3.6 V VDD_IO I/O and voltage regulator supply voltage VDDIO_R1 I/O voltage ramp for reset activation; Note 1 Ramp starts at VDD_IO≤0.1V 0.1 V/ms VDDIO_R2 I/O voltage ramp for reset activation; Note 1 Ramp starts at 0.1V<VDD_IO<0.7V 3.3 V/ms VREG Internally regulated analog supply voltage IDEEPSLEEP Deep Sleep current ISLEEP256PIN Sleep current, 256 Bytes RAM retained ISLEEP256 Power-down mode AX5031_PWRMODE=0x00 All other power modes 1.7 2.1 2.5 V 2.8 V 250 nA Wakeup from dedicated pin 700 nA Sleep current, 256 Bytes RAM retained Wakeup Timer running at 640Hz 1.1 μA ISLEEP4K Sleep current, 4.25 kBytes RAM retained Wakeup Timer running at 640Hz 1.7 μA ISLEEP8K Sleep current, 8.25 kBytes RAM retained Wakeup Timer running at 640Hz 2.4 μA 868 MHz, 15 dBm 22 868 MHz, 0 dBm 13 868 MHz, 15 dBm 45 433 MHz, 10 dBm 22 433 MHz, 0 dBm 13 Current consumption TX for maximum power with default matching network at 3.3V VDD_IO, note 2 ITX mA 433 MHz, 15 dBm 45 TXvarvdd Variation of output power over voltage VDD_IO > 2.5V, note 2 +/0.5 dB TXvartemp Variation of output power over temperature VDD_IO > 2.5V, note 2 +/0.5 dB IMCU Microcontroller running power consumption All peripherals disabled 150 IVSUP Voltage supervisor Run and standby mode 85 μA IXTALOSC Crystal oscillator current (RF reference oscillator) 16 MHz 160 μA ILFXTALOSC Low frequency crystal oscillator current 32 kHz 700 nA IRCOSC Internal oscillator current 20 MHz 210 μA ILPOSC Internal Low Power Oscillator current 10 kHz 650 nA 640 Hz 210 nA IADC ADC current 311 kSample/s, DMA 5 MHz 1.1 mA Notes: 1. 2. μA/ MHz If VDD_IO ramps cannot be guaranteed, an external reset circuit is recommended, see the AX8052 Application Note: Power On Reset The PA voltage is regulated to 2.5 V. For VDD_IO levels in the range of 2.2 V to 2.55 V the output power drops by typically 1 dBm. www.onsemi.com AX8052F131 Specifications Note on current consumption in TX mode To achieve best output power the matching network has to be optimized for the desired output power and frequency. As a rule of thumb a good matching network produces about 50% efficiency with the AX8052F131 power amplifier although over 90% are theoretically possible. A typical matching network has between 1 dB and 2 dB loss (Ploss). The current consumption can be calculated as ITX[mA]=1/PAefficiency*10^((Pout[dBm]+Ploss[dB])/10)/2.5V+Ioffset Ioffset is about 12 mA for the VCO at 400-470 MHz and 11 mA for 800-940 MHz. The following table shows calculated current consumptions versus output power for Ploss = 1 dB, PAefficiency = 0.5 and Ioffset= 11 mA at 868 MHz Pout [dBm] I [mA] 0 13.0 1 13.2 2 13.6 3 14.0 4 14.5 5 15.1 6 16.0 7 17.0 8 18.3 9 20.0 10 22.0 11 24.6 12 27.96 13 32.1 14 37.3 15 43.8 The AX8052F131 power amplifier runs from the regulated VDD supply and not directly from the battery. This has the advantage that the current and output power do not vary much over supply voltage and temperature from 2.55 V to 3.6 V supply voltage. Between 2.55 V and 2.2 V a drop of about 1 dB in output power occurs. www.onsemi.com AX8052F131 13 14 Specifications Logic SYMBOL DESCRIPTION CONDITION MIN TYP MAX UNIT DIGITAL INPUTS VT+ Schmitt trigger low to high threshold point VT- Schmitt trigger high to low threshold point VIL Input voltage, low VIH Input voltage, high 2.0 VIPA Input voltage range, Port A -0.5 VDD_IO V VIPBC Input voltage range, Ports B, C -0.5 5.5 V IL Input leakage current -10 10 μA RPU Programmable Pull-Up Resistance VDD_IO = 3.3V 1.55 V 1.25 V 0.8 V V kΩ 65 DIGITAL OUTPUTS IOH P[ABC]x Output Current, high VOH= 2.4V 8 mA IOL P[ABC]x Output Current, low VOL= 0.4V 8 mA IPROH SYSCLK Output Current, high VOH= 2.4V 8 mA IPROL SYSCLK Output Current, low VOL= 0.4V 8 mA IOZ Tri-state output leakage current www.onsemi.com -10 10 μA AX8052F131 Specifications 4.3. AC Characteristics Crystal Oscillator (RF reference oscillator) SYMBOL DESCRIPTION CONDITION MIN TYP MAX UNIT fXTAL Crystal frequency Note 1, 3 15.5 16 25 MHz gmosc Transconductance oscillator Programmable tuning capacitors at pins CLK16N and CLK16P Cosc Cosc-lsb Programmable tuning capacitors, increment per LSB of AX5031_XTALCAP fext External clock input (TCXO) Aosc Oscillator amplitude at pin CLK16P RINosc Input DC impedance AX5031_XTALOSCGM=0000 1 AX5031_XTALOSCGM=0001 2 AX5031_XTALOSCGM =0010 default 3 AX5031_XTALOSCGM =0011 4 AX5031_XTALOSCGM =0100 5 AX5031_XTALOSCGM =0101 6 AX5031_XTALOSCGM =0110 6.5 AX5031_XTALOSCGM =0111 7 AX5031_XTALOSCGM =1000 7.5 AX5031_XTALOSCGM =1001 8 AX5031_XTALOSCGM =1010 8.5 AX5031_XTALOSCGM =1011 9 AX5031_XTALOSCGM =1100 9.5 AX5031_XTALOSCGM =1101 10 AX5031_XTALOSCGM =1110 10.5 AX5031_XTALOSCGM =1111 11 AX5031_XTALCAP=000000 default AX5031_XTALCAP=111111 Note 2, 3 15.5 10 mS 2 pF 33 pF 0.5 pF 16 25 MHz 0.5 V kΩ Notes 1. 2. 3. Tolerances and start-up times depend on the crystal used. Depending on the RF frequency and channel spacing the IC must be calibrated to the exact crystal frequency using the readings of the register AX5031_TRKFREQ If an external clock is used, it should be input via an AC coupling at pin CLK16P with the oscillator powered up and AX5031_XTALCAP=000000 Lower frequencies than 15.5 MHz or higher frequencies than 25 MHz can be used. However not all typical RF frequencies can than be generated. www.onsemi.com AX8052F131 15 16 Specifications RF Frequency Generation Subsystem (Synthesizer) SYMBOL DESCRIPTION CONDITION fREF Reference frequency Note 1 frange_hi frange_low fRESO Frequency range MIN TYP 16 BANDSEL=0 800 940 BANDSEL=1 400 470 Frequency resolution 1 100 BW2 Synthesizer loop bandwidth Loop filter configuration: FLT=01 Charge pump current: PLLCPI=001 50 VCO current: VCOI=001 Loop filter configuration: FLT=11 kHz 200 BW4 Loop filter configuration: FLT=10 Charge pump current: PLLCPI=010 500 Tset1 Loop filter configuration: FLT=01 Charge pump current: PLLCPI=010 15 Tset2 Loop filter configuration: FLT=01 Charge pump current: PLLCPI=001 30 Loop filter configuration: FLT=11 Charge pump current: PLLCPI=010 7 Tset4 Loop filter configuration: FLT=10 Charge pump current: PLLCPI=010 3 Tstart1 Loop filter configuration: FLT=01 Charge pump current: PLLCPI=010 25 Loop filter configuration: FLT=01 Charge pump current: PLLCPI=001 50 Loop filter configuration: FLT=11 Charge pump current: PLLCPI=010 12 Tset3 Tstart2 Synthesizer settling time for 1MHz step VCO current: VCO_I=001 Synthesizer start-up time if crystal oscillator and reference are running VCO current: VCO_I=001 Tstart3 www.onsemi.com MHz Hz BW1 Charge pump current: PLLCPI=010 UNIT MHz 24 Loop filter configuration: FLT=01 Charge pump current: PLLCPI=010 BW3 MAX μs μs AX8052F131 Specifications Loop filter configuration: FLT=10 Charge pump current: PLLCPI=010 Tstart4 PN8681 PN4331 PN8682 PN4332 Synthesizer phase noise Loop filter configuration: FLT=01 Charge pump current: PLLCPI=010 VCO current: VCO_I=001 Synthesizer phase noise Loop filter configuration: FLT=01 Charge pump current: PLLCPI=001 VCO current: VCO_I=001 5 868 MHz, 50 kHz from carrier -85 868 MHz, 100 kHz from carrier -90 868 MHz, 300 kHz from carrier -100 868 MHz, 2 MHz from carrier -110 433 MHz, 50 kHz from carrier -90 433 MHz, 100 kHz from carrier -95 433 MHz, 300 kHz from carrier -105 433 MHz, 2 MHz from carrier -115 868 MHz, 50 kHz from carrier -80 868 MHz, 100 kHz from carrier -90 868 MHz, 300 kHz from carrier -105 868 MHz, 2 MHz from carrier -115 433 MHz, 50 kHz from carrier -90 433 MHz, 100 kHz from carrier -95 433 MHz, 300 kHz from carrier -110 433 MHz, 2 MHz from carrier -122 dBc/Hz dBc/Hz Notes: 1. ASK, PSK and 1-200 kbps FSK with 16 MHz crystal, 200-350 kbps FSK with 24 MHz crystal www.onsemi.com AX8052F131 17 18 Specifications Transmitter SYMBOL SBR DESCRIPTION Signal bit rate Transmitter power PTX868 @868 MHz Transmitter power PTX433 @433 MHz PTX868-harm2 Emission @ 2nd harmonic PTX868-harm3 Emission @ 3rd harmonic CONDITION MIN TYP MAX ASK 1 2000 PSK 10 2000 FSK, note 2 1 350 802.15.4 (DSSS) ASK and PSK 1 40 802.15.4 (DSSS) FSK 1 16 UNIT kbps TXRNG=1111 15 dBm TXRNG=1111 16 dBm Note 1 -50 -55 dBc Notes 1. 2. Additional low-pass filtering was applied to the antenna interface, see applications section. 1-200 kbps with a 16 MHz crystal, 200-350 kbps with a 24 MHz crystal www.onsemi.com AX8052F131 Specifications Low Frequency Crystal Oscillator SYMBOL DESCRIPTION fLPXTAL Crystal frequency gmlpxosc RINlpxosc CONDITION Transconductance oscillator MIN TYP MAX UNIT 32 150 kHz LPXOSCGM=00110 3.5 LPXOSCGM=01000 4.6 LPXOSCGM=01100 6.9 LPXOSCGM=10000 9.1 Input DC impedance µS MΩ 10 Internal Low Power Oscillator SYMBOL DESCRIPTION CONDITION MIN TYP MAX UNIT 630 640 650 Hz 10.08 10.24 10.39 kHz MIN TYP MAX UNIT 19.8 20 20.2 MHz LPOSCFAST=0 Factory calibration applied. fLPOSC Oscillation Frequency Over the full voltage and temperature range LPOSCFAST=1 Factory calibration applied. Over the full voltage and temperature range Internal RC Oscillator SYMBOL DESCRIPTION CONDITION Factory calibration applied. FFRCOSC Oscillation Frequency Over the full temperature and voltage range www.onsemi.com AX8052F131 19 Specifications Microcontroller SYMBOL DESCRIPTION TSYSCLKL SYSCLK Low 27 ns TSYSCLKH SYSCLK High 21 ns TSYSCLKP SYSCLK Period 47 ns TFLWR FLASH Write Time 2 Bytes TFLPE FLASH Page Erase 1 kBytes TFLE FLASH Secure Erase 64 kBytes TFLEND FLASH Endurance: Erase Cycles CONDITION MIN 10’000 TYP MAX UNIT 20 µs 2 ms 10 ms 100’000 Cycles O TFLRETroom FLASH Data Retention TFLREThot 25 C See Figure 3 for the lower limit set by the memory qualification 100 85OC See Figure 3 for the lower limit set by the memory qualification 10 Years 100000 Data retention time [years] 20 10000 1000 100 10 15 25 35 45 55 65 75 85 o Temperature [ C] Figure 3 FLASH memory qualification limit for data retention after 10k erase cycles www.onsemi.com AX8052F131 Specifications ADC / Comparator / Temperature Sensor SYMBOL DESCRIPTION ADCSR ADC sampling rate GPADC mode 30 ADCSR_T ADC sampling rate temperature sensor mode 10 ADCRES ADC resolution VADCREF ADC reference voltage & comparator internal reference voltage ZADC00 Input capacitance DNL Differential nonlinearity INL Integral nonlinearity OFF Offset GAIN_ERR Gain error CONDITION MIN TYP 15.6 MAX UNIT 500 kHz 30 kHz 10 0.95 1 Bits 1.05 V 2.5 pF +/- 1 LSB +/- 1 LSB 3 LSB 0.8 % ADC in Differential Mode VABS_DIFF Absolute voltages & common mode voltage in differential mode at each input VFS_DIFF01 Full swing input for differential signals VFS_DIFF10 Gain x1 Gain x10 0 VDD_IO V -500 500 mV -50 50 mV ADC in Single Ended Mode VMID_SE Mid code input voltage in single ended mode VIN_SE00 Input voltage in single ended mode VFS_SE01 Full swing input for single ended signals 0.5 Gain x1 V 0 VDD_IO V 0 1 V Comparators VCOMP_ABS Comparator absolute input voltage 0 VDD_IO V VCOMP_COM Comparator input common mode 0 VDD_IO0.8 V VCOMPOFF Comparator input offset voltage 20 mV 85 °C Temperature Sensor TRNG Temperature range TRES Temperature resolution TERR_CAL Temperature error -40 0.1607 Factory calibration applied www.onsemi.com -2 °C/LSB +2 °C AX8052F131 21 22 Circuit Description 5. Circuit Description The AX8052F131 is a single chip ultra-low-power RF-microcontroller SoC primarily for use in SRD bands. The on-chip transmitter consists of a fully integrated RF front-end with modulator, and demodulator. Base band data processing is implemented in an advanced and flexible communication controller that enables user friendly communication. The AX8052F131 contains a high speed microcontroller compatible to the industry standard 8052 instruction set. It contains 64 kBytes of FLASH and 8.25 kBytes of internal SRAM. The AX8052F131 features 3 16-bit general purpose timers with Σ∆ capability, 2 output compare units for generating PWM signals, 2 input compare units to record timings of external signals, 2 16-bit wakeup timers, a watchdog timer, 2 UARTs, a Master/Slave SPI controller, a 10-bit 500 kSample/s A/D converter, 2 analog comparators, a temperature sensor, a 2 channel DMA controller, and a dedicated AES crypto controller. Debugging is aided by a dedicated hardware debug interface controller that connects using a 3-wire protocol (1 dedicated wire, 2 shared with GPIO) to the PC hosting the debug software. While the radio carrier can only be clocked by the crystal oscillator (carrier stability requirements dictate a high stability reference clock in the MHz range), the microcontroller and its peripherals provide extremely flexible clocking options. The system clock that clocks the microcontroller, as well as peripheral clocks, can be selected from one of the following clock sources: the crystal oscillator, an internal high speed 20 MHz oscillator, an internal low speed 640 Hz/10 kHz oscillator, or the low frequency crystal oscillator. Prescalers offer additional flexibility with their programmable divide by a power of two capability. To improve the accuracy of the internal oscillators, both oscillators may be slaved to the crystal oscillator. AX8052F131 can be operated from a 2.2 V to 3.6 V power supply over a temperature range of –40oC to 85oC, it consumes 11 - 45 mA for transmitting, depending on the output power. The AX8052F131 features make it an ideal interface for integration into various battery powered SRD solutions such as ticketing or as transmitter for telemetric applications e.g. in sensors. As primary application, the transmitter is intended for UHF radio equipment in accordance with the European Telecommunication Standard Institute (ETSI) specification EN 300 220-1 and the US Federal Communications Commission (FCC) standard CFR47, part 15. The use of AX8052F131 in accordance to FCC Par 15.247, allows for improved range in the 915 MHz band. Additionally AX8052F131 is compatible with the low frequency standards of 802.15.4 (ZigBee) and suited for systems targeting compliance with Wireless M-Bus standard EN 13757-4:2005 The AX8052F131 sends data in frames. This standard operation mode is called Frame Mode. Pre and post ambles as well as checksums can be generated automatically. AX8052F131 supports any data rate from 1 kbps to 350 kbps for FSK and MSK, from 1 kbps to 2000 kbps for ASK and from 10 kbps to 2000 kbps for PSK. To achieve optimum performance for specific data rates and modulation schemes several register settings to configure the AX8052F131 are necessary, they are outlined in the following, for details see the AX5031 Programming Manual. Spreading is possible on all data rates and modulation schemes. The net transfer rate is reduced by a factor of 15 in this case. For ZigBee either 600 or 300 kbps modes have to be chosen. The transmitter supports multi-channel operation for all data rates and modulation schemes. www.onsemi.com AX8052F131 Circuit Description 5.1. Microcontroller The AX8052F131 microcontroller core executes the industry standard 8052 instruction set. Unlike the original 8052, many instructions are executed in a single cycle. The system clock and thus the instruction rate can be programmed freely from DC to 20MHz. Memory Architecture DMA AES Cache Prefetch AX8052 X Bus SFR Bus IRAM Bus Code Bus Arbiter Arbiter Arbiter Arbiter Arbiter Arbiter XRAM XRAM X Registers SFR Registers IRAM FLASH 0000-0FFF 1000-1FFF 4000-7FFF 80-FF 00-FF 0000-FFFF Figure 4 AX8052 Memory Architecture The AX8052 Microcontroller features the highest bandwidth memory architecture of its class. Figure 4 shows the memory architecture. Three bus masters may initiate bus cycles: • The AX8052 Microcontroller Core • The Direct Memory Access (DMA) Engine • The Advanced Encryption Standard (AES) Engine Bus targets include: • Two individual 4 kBytes RAM blocks located in X address space, which can be simultaneously accessed and individually shut down or retained during sleep mode • A 256 Byte RAM located in internal address space, which is always retained during sleep mode • A 64 kBytes FLASH memory located in code space. • Special Function Registers (SFR) located in internal address space accessible using direct address mode instructions • Additional Registers located in X address space (X Registers) www.onsemi.com AX8052F131 23 24 Circuit Description The upper half of the FLASH memory may also be accessed through the X address space. This simplifies and makes the software more efficient by reducing the need for generic pointers2. SFR Registers are also accessible through X address space, enabling indirect access to SFR registers. This allows driver code for multiple identical peripherals (such as UARTs or Timers) to be shared. The 4 word × 16 bit fully associative cache and a pre-fetch controller hide the latency of the FLASH. The AX8052 Memory Architecture is fully parallel. All bus masters may simultaneously access different bus targets during each system clock cycle. Each bus target includes an arbiter that resolves access conflicts. Each arbiter ensures that no bus master can be starved. Both 4 kBytes RAM blocks may be individually retained or switched off during sleep mode. The 256 Byte RAM is always retained during sleep mode. The AES engine accesses memory 16bits at a time. It is therefore slightly faster to align its buffers on even addresses. Memory Map I (internal) Space Address P (Code) Space X Space direct access 0000-007F IRAM XRAM 0080-00FF SFR indirect access IRAM 0100-1FFF IRAM 2000-207F 2080-3F7F 3F80-3FFF FLASH SFR 4000-4FFF RREG 5000-5FFF RREG (nb) 6000-7FFF XREG 8000-FBFF FLASH FC00-FFFF Calibration Data Calibration Data Figure 5 AX8052 Memory Map The AX8052, like the other industry standard 8052 compatible microcontrollers, uses a Harvard architecture. Multiple address spaces are used to access code and data. Figure 5 shows the AX8052 memory map. 2 Generic pointers include, in addition to the address, an address space tag. www.onsemi.com AX8052F131 Circuit Description The AX8052 uses P or Code Space to access its program. Code space may also be read using the MOVC instruction. Smaller amounts of data can be placed in the Internal 3 or Data Space. A distinction is made in the upper half of the Data Space between direct accesses (MOV reg,addr; MOV addr,reg) and indirect accesses (MOV reg,@Ri; MOV @Ri,reg; PUSH; POP); Direct accesses are routed to the Special Function Registers, while indirect accesses are routed to the internal RAM. Large amounts of data can be placed in the External or X Space. It can be accessed using the MOVX instructions. Special Function Registers, as well as additional Microcontroller Registers (XREG) and the Radio Registers (RREG) are also mapped into the X Space. Detailed documentation of the Special Function Registers (SFR) and additional Microcontroller Registers can be found in the AX8052 Programming Manual. The Radio Registers are documented in the AX5031 Programming Manual. Register Addresses given in the AX5031 Programming Manual are relative to the beginning of RREG, i.e. 0x4000 must be added to these addresses. It is recommended that the Axsem provided ax8052f131.h header file is used; Radio Registers are prefixed with AX5031_ in the ax8052f131.h header file to avoid clashes of same-name Radio registers with AX8052 registers. Normally, accessing Radio Registers through the RREG address range is adequate. Since Radio Register accesses have a higher latency than other AX8052 registers, the AX8052 provides a method for non-blocking access to the Radio Registers. Accessing the RREG (nb) address range initiates a Radio Register access, but does not wait for its completion. The details of mechanism is documented in the Radio Interface section of the AX8052 Programming Manual. The FLASH memory is organized as 64 pages of 1 kBytes each. Each page can be individually erased. The write word size is 16 Bits. The last 1 kByte page is dedicated to factory calibration data and should not be overwritten. Power Management The microcontroller power mode can be selected independently from the transmitter. The microcontroller supports the following power modes: PCON register 00 01 10 Name Description RUNNING The microcontroller and all peripherals are running. Current consumption depends on the system clock frequency and the enabled peripherals and their clock frequency. STANDBY The microcontroller is stopped. All register and memory contents are retained. All peripherals continue to function normally. Current consumption is determined by the enabled peripherals. STANDBY is exited when any of the enabled interrupts become active. SLEEP The microcontroller and its peripherals, except GPIO and the system controller, are shut down. Their register settings are lost. The internal RAM is retained. The external RAM is split into two 4kByte blocks. Software can determine individually for both blocks whether contents of that block are to be retained or lost. SLEEP can be exited 3 The origin of Internal versus External (X) Space is historical. External Space used to be outside of the chip on the original 8052 Microcontrollers. www.onsemi.com AX8052F131 25 26 Circuit Description by any of the enabled GPIO or system controller interrupts. For most applications this will be a GPIO or wakeup timer interrupt. 11 DEEPSLEEP The microcontroller, all peripherals and the transmitter are shut down. Only 4 bytes of scratch RAM are retained. DEEPSLEEP can only be exited by tying the PB3 pin low. Clocking WDT LPOSC Calib FRCOSC XOSC Glitch Free Clock Switch FRCOSC Calib LPOSC Internal Reset Wakeup Timer Interrupt Prescaler System Clock ÷1,2,4,... Clock Monitor LPXOSC SYSCLK Figure 6 Clock System Diagram The system clock can be derived from any of the following clock sources: • The crystal oscillator (RF reference oscillator, typically 16 MHz, via SYSCLK) • The low speed crystal oscillator (typical 32 kHz tuning fork) • The internal high speed RC (20 MHz) oscillator • The internal low power (640 Hz/10 kHz) oscillator An additional pre-scaler allows the selected oscillator to be divided by a power of two. After reset, the microcontroller starts with the internal high speed RC oscillator selected and divided by two. I.e. at start-up, the microcontroller runs with 10 MHz ± 10%. Clocks may be switched any time by writing to the CLKCON register. In order to prevent clock glitches, the switching takes approximately 2·(T1+T2), where T1 and T2 are the periods of the old and the new clock. Switching www.onsemi.com AX8052F131 Circuit Description may take longer if the new oscillator first has to start up. Internal oscillators start up instantaneously, but crystal oscillators may take a considerable amount of time to start the oscillation. CLKSTAT can be read to determine the clock switching status. A programmable clock monitor resets the CLKCON register when no system clock transitions are found during a programmable time interval, thus reverts to the internal RC oscillator. Both internal oscillators can be slaved to one of the crystal oscillators to increase the accuracy of the oscillation frequency. While the reference oscillator runs, the internal oscillator is slaved to the reference frequency by a digital frequency locked loop. When the reference oscillator is switched off, the internal oscillator continues to run unslaved with the last frequency setting. Reset and Interrupts After reset, the microcontroller starts executing at address 0x0000. Several events can lead to resetting the microcontroller core: • POR or hardware RESET_N pin activated and released • Leaving SLEEP or DEEPSLEEP mode • Watchdog Reset • Software Reset The reset cause can be determined by reading the PCON register. The microcontroller supports 22 interrupt sources. Each interrupt can be individually enabled and can be programmed to have one of two possible priorities. The interrupt vectors are located at 0x0003, 0x000B, …, 0x00AB. Debugging A hardware debug unit considerably eases debugging compared to other 8052 microcontrollers. It allows to reliably stop the microcontroller at breakpoints even if the stack is smashed. The debug unit communicates with the host PC running the debugger using a 3 wire interface. One wire is dedicated (DBG_EN), while two wires are shared with GPIO pins (PB6, PB7). When DBG_EN is driven high, PB6 and PB7 convert to debug interface pins and the GPIO functionality is no longer available. A pin emulation feature however allows bits PINB[7:6] to be set and PORTB[7:6] and DIRB[7:6] to be read by the debugger software. This allows for example switches or LEDs connected to the PB6, PB7 pins to be emulated in the debugger software whenever the debugger is active. In order to protect the intellectual property of the firmware developer, the debug interface can be locked using a developer-selectable 64-bit key. The debug interface is then disabled and can only be enabled with the knowledge of this 64-bit key. Therefore, unauthorized persons cannot read the firmware through the debug interface, but debugging is still possible for authorized persons. Secure erase can be initiated without key knowledge; secure erase ensures that the main FLASH array is completely erased before erasing the key, reverting the chip into factory state. The DebugLink peripheral looks like an UART to the microcontroller, and allows exchange of data between the microcontroller and the host PC without disrupting program execution. www.onsemi.com AX8052F131 27 28 Circuit Description 5.2. Timer, Output Compare and Input Capture The AX8052F131 features three general purpose 16-bit timers. Each timer can be clocked by the system clock, any of the available oscillators, or a dedicated input pin. The timers also feature a programmable clock inversion, a programmable prescaler that can divide by powers of two, and an optional clock synchronization logic that synchronizes the clock to the system clock. All three counters are identical and feature four different counting modes, as well as a Σ∆ mode that can be used to output an analog value on a dedicated digital pin only employing a simple RC lowpass filter. Two output compare units work in conjunction with one of the timers to generate PWM signals. Two input capture units work in conjunction with one of the timers to measure transitions on an input signal. For software timekeeping, two additional 16-bit wakeup timers with 4 16-bit event registers are provided, generating an interrupt on match events. 5.3. UART The AX8052F131 features two universal asynchronous receiver transmitters. They use one of the timers as baud rate generator. Word length can be programmed from 5 to 9 bits. 5.4. SPI Master/Slave Controller The AX8052F131 features a master/slave SPI controller. Both 3 and 4 wire SPI variants are supported. In master mode, any of the on-chip oscillators or the system clock may be selected as clock source. An additional prescaler with divide by two capability provides additional clocking flexibility. Shift direction, as well as clock phase and inversion, are programmable. www.onsemi.com AX8052F131 Circuit Description System Clock SYSCLK LPXOSC XOSC VDDIO LPOSC Temperature Sensor FRCOSC ADCCLKSRC 5.5. ADC, Analog Comparators and Temperature Sensor Free Running One Shot PA6 Timer 0 PA5 Timer 1 Prescaler ÷1,2,4,8,... PA7 PA4 PA3 PA2 PA1 Clock PA0 Timer 2 PC4 ADC Core PPP ADC Result Ref ×0.1, ×1, ×10 Gain ADCCONV Trigger VREF 1V 0.5V Single Ended NNN ACOMP0IN ACOMP0REF ACOMP0ST/PA4/PC3 ACOMP0INV System Clock ACOMP1IN ACOMP1REF ACOMP1ST/PA7/PC1 ACOMP1INV Figure 7 ADC Block Diagram The AX8052F131 features a 10-bit, 500 kSample/s Analog to Digital converter. The ADC supports both single ended and differential measurements. It uses an internal reference of 1 V. ×1, ×10 and ×0.1 gain modes are provided. The ADC may digitize signals on PA0…PA7, as well as VDD_IO and an internal temperature sensor. The user can define four channels which are then converted sequentially and stored in four separate result registers. Each channel configuration consists of the multiplexer and the gain setting. www.onsemi.com AX8052F131 29 30 Circuit Description The AX8052F131 contains an on-chip temperature sensor. Built-in calibration logic allows the temperature sensor to be calibrated in °C, °F or any other user defined temperature scale. The AX8052F131 also features two analog comparators. Each comparator can either compare two voltages on dedicated PA pins, or one voltage against the internal 1V reference. The comparator output can be routed to a dedicated digital output pin or can be read by software. The comparators are clocked with the system clock. 5.6. DMA Controller The AX8052F131 features a dual channel DMA engine. Each DMA channel can either transfer data from XRAM to almost any peripheral on chip, or from almost any peripheral to XRAM. Both channels may also be cross-linked for memory-memory transfers. The DMA channels use buffer descriptors to find the buffers where data is to be retrieved or placed, thus enabling very flexible buffering strategies. The DMA channels access XRAM in a cycle steal fashion. They access XRAM whenever XRAM is not used by the microcontroller. Their priority is lower than the microcontroller, thus interfering very little with the microcontroller. Additional logic prevents starvation of the DMA controller. 5.7. AES Engine The AX8052F131 contains a dedicated engine for the government mandated Advanced Encryption Standard (AES). It features a dedicated DMA engine and reads input data as well as key stream data from the XRAM, and writes output data into a programmable buffer in the XRAM. The round number is programmable; the chip therefore supports AES-128, AES-192, and AES-256, as well as higher security proprietary variants. Keystream (key expansion) is performed in software, adding to the flexibility of the AES engine. ECB (electronic codebook), CFB (cipher feedback) and OFB (output feedback) modes are directly supported without software intervention. 5.8. Crystal Oscillator (RF reference oscillator) The on-chip crystal oscillator allows the use of an inexpensive quartz crystal as the RF generation subsystem’s timing reference. Although a wider range of crystal frequencies can be handled by the crystal oscillator circuit, it is recommended to use 16 MHz as reference frequency for ASK and PSK modulations independent of the data rate. For FSK it is recommended to use a 16 MHz crystal for data rates below 200 kbps and 24 MHz for data rates above 200 kbps. The oscillator circuit is enabled by programming the transmitter AX5031_PWRMODE register. At power-up it is not enabled. To adjust the circuit’s characteristics to the quartz crystal being used, without using additional external components, both the transconductance and the tuning capacitance of the crystal oscillator can be programmed. The transconductance AX5031_XTALOSC. is programmed via register www.onsemi.com bits XTALOSCGM[3:0] in register AX8052F131 Circuit Description The integrated programmable tuning capacitor bank makes it possible to connect the oscillator directly to pins CLK16N and CLK16P without the need for external capacitors. It is programmed using bits XTALCAP[5:0] in register AX5031_XTALCAP. Alternatively a single ended reference (TCXO, CXO) may be used. The CMOS levels should be applied to CLK16P via an AC coupling with the crystal oscillator enabled. 5.9. SYSCLK Output The SYSCLK pin outputs the reference clock signal divided by a programmable integer. Divisions from 1 to 2048 are possible. For divider ratios > 1 the duty cycle is 50%. Bits SYSCLK[3:0] in the AX5031_PINCFG1 register set the divider ratio. The SYSCLK output can be disabled. 5.10. Power-on-reset (POR) and RESET_N Input AX8052F131 has an integrated power-on-reset block which is edge sensitive to VDD_IO. For many common application cases no external reset circuitry is required. However, if VDD_IO ramps cannot be guaranteed, an external reset circuit is recommended. For detailed recommendations and requirements see the AX8052 Application Note: Power On Reset. After POR or reset all registers are set to their default values. The RESET_N pin contains a weak pull-up. However, it is strongly recommended to connect the RESET_N pin to VDD_IO if not used, for additional robustness. The AX8052F131 can be reset by software as well. The microcontroller is reset by writing 1 to the SWRESET bit of the PCON register. The Transmitter can be reset by first writing 1 and then 0 to the RST bit in the AX5031_PWRMODE register. www.onsemi.com AX8052F131 31 32 Circuit Description 5.11. Ports VDDIO PORTx.y DIRx.y 65 kΩ Special Function PALTx.y INTCHGx.y Interrupt PINx.y PINx read clock ANALOGx.y Figure 8 Port pin schematic Figure 8 shows the GPIO logic. The DIR register bit determines whether the port pin acts as an output (1) or an input (0). If configured as an output, the PALT register bit determines whether the port pin is connected to a peripheral output (1), or used as a GPIO pin (0). In the latter case, the PORT register bit determines the port pin drive value. If configured as an input, the PORT register bit determines whether a pull-up resistor is enabled (1) or disabled (0). Inputs have schmitt-trigger characteristic. Port A inputs may be disabled by setting the ANALOGA register bit; this prevents additional current consumption if the voltage level of the port pin is mid-way between logic low and logic high, when the pin is used as an analog input. Port A, B and C pins may interrupt the microcontroller if their level changes. The INTCHG register bit enables the interrupt. The PIN register bit reflects the value of the port pin. Reading the PIN register also resets the interrupt if interrupt on change is enabled. www.onsemi.com AX8052F131 Transmitter 6. Transmitter The transmitter block is controllable through its registers, which are mapped into the X data space of the microcontroller. The transmitter block features its own 32 word × 10 bit FIFO. The microcontroller can either be interrupted at a programmable FIFO fill level, or one of the DMA channels can be instructed to transfer between XRAM and the transmitter FIFO. 6.1. RF Frequency Generation Subsystem The RF frequency generation subsystem consists of a fully integrated synthesizer, which multiplies the reference frequency from the crystal oscillator to get the desired RF frequency. The advanced architecture of the synthesizer enables frequency resolutions of 1 Hz, as well as fast settling times of 5 – 50 µs depending on the settings (see section 4.3: AC Characteristics). Fast settling times mean fast start-up, which enables low-power system design. The frequency must be programmed to the desired carrier frequency. The synthesizer loop bandwidth can be programmed. This serves three purposes: 1. Start-up time optimization, start-up is faster for higher synthesizer loop bandwidths 2. TX spectrum optimization, phase-noise at 300 kHz to 1 MHz distance from the carrier improves with lower synthesizer loop bandwidths 3. Adaptation of the bandwidth to the data-rate. For transmission of FSK and MSK it is required that the synthesizer bandwidth must be in the order of the data-rate. VCO An on-chip VCO converts the control voltage generated by the charge pump and loop filter into an output frequency. The frequency can be programmed in 1 Hz steps in the AX5031_FREQ registers. For operation in the 433 MHz band, the BANDSEL bit in the AX5031_PLLLOOP register must be programmed. VCO Auto-Ranging The AX8052F131 has an integrated auto-ranging function, which allows to set the correct VCO range for specific frequency generation subsystem settings automatically. Typically it has to be executed after power-up. The function is initiated by setting the RNG_START bit in the AX5031_PLLRANGING register. The bit is readable and a 0 indicates the end of the ranging process. The RNGERR bit indicates the correct execution of the auto-ranging. www.onsemi.com AX8052F131 33 34 Transmitter Loop Filter and Charge Pump The AX8052F131 internal loop filter configuration together with the charge pump current sets the synthesizer loop band width. The loop-filter has three configurations that can be programmed via the register bits FLT[1:0] in register AX5031_PLLLOOP, the charge pump current can be programmed using register bits PLLCPI[1:0] also in register AX5031_PLLLOOP. Synthesizer bandwidths are typically 50 - 500 kHz depending on the AX5031_PLLLOOP settings, for details see the section 4.3: AC Characteristics. Registers Register Bits Purpose FLT[1:0] Synthesizer loop filter bandwidth, recommended usage is to increase the bandwidth for faster settling time, bandwidth increases of factor 2 and 5 are possible. PLLCPI[2:0] Synthesizer charge pump current, recommended usage is to decrease the bandwidth (and improve the phase-noise) for low data-rate transmissions. BANDSEL Switches between 868 MHz/915 MHz and 433 MHz bands AX5031_PLLLOOP AX5031_FREQ Programming of the carrier frequency AX5031_FREQB Programming of the 2nd carrier frequency, switch to this carrier frequency by setting bit FREQSEL=1. AX5031_PLLRANGING Initiate VCO auto-ranging and check results www.onsemi.com AX8052F131 Transmitter 6.2. RF Input and Output Stage (ANTP/ANTN) The AX8052F131 uses fully differential antenna pins. The PA drives the signal generated by the frequency generation subsystem out to the differential antenna terminals. The output power of the PA is programmed via bits TXRNG[3:0] in the register AX5031_TXPWR. Output power as well as harmonic content will depend on the external impedance seen by the PA, recommendations are given in section 7.1: Antenna Interface Circuitry. 6.3. Encoder The encoder is located between the Framing Unit and the Modulator. It can optionally transform the bit-stream in the following ways: • It can invert the bit stream. • It can perform differential encoding. This means that a zero is transmitted as no change in the level, and a one is transmitted as a change in the level. Differential encoding is useful for PSK, because PSK transmissions can be received either as transmitted or inverted, due to the uncertainty of the initial phase. Differential encoding / decoding removes this uncertainty. • It can perform Manchester encoding. Manchester encoding ensures that the modulation has no DC content and enough transitions (changes from 0 to 1 and from 1 to 0) for the demodulator bit timing recovery to function correctly, but does so at a doubling of the data rate. • It can perform Spectral Shaping. Spectral Shaping removes DC content of the bit stream, ensures transitions for the demodulator bit timing recovery, and makes sure that the transmitted spectrum does not have discrete lines even if the transmitted data is cyclic. It does so without adding additional bits, i.e. without changing the data rate. Spectral Shaping uses a self synchronizing feedback shift register. The encoder is programmed using the register AX5031_ENCODING, recommendations on usage are given in the AX5031 Programming Manual. www.onsemi.com details and AX8052F131 35 36 Transmitter 6.4. Framing and FIFO Most radio systems today group data into packets. The framing unit is responsible for converting these packets into a bit-stream suitable for the modulator. The Framing unit supports three different modes: • HDLC • Raw • 802.15.4 compliant The microcontroller communicates with the framing unit through a 32 level × 10 bit FIFO. The FIFO decouples microcontroller timing from the radio (modulator) timing. The bottom 8 bits of the FIFO contain transmit data. The top 2 bit are used to convey meta information in HDLC and 802.15.4 modes. They are unused in Raw mode. The meta information consists of packet begin / end information and the result of CRC checks. The FIFO can be operated in polled or interrupt driven modes. In polled mode, the microcontroller must periodically read the FIFO status register or the FIFO count register to determine whether the FIFO needs servicing. In interrupt mode EMPTY, NOT EMPTY, FULL, NOT FULL and programmable level interrupts are provided. Interrupts are acknowledged by removing the cause for the interrupt, i.e. by emptying or filling the FIFO. To lower the interrupt load on the microcontroller, one of the DMA channels may be instructed to transfer data between the transmitter FIFO and the XRAM memory. This way, much larger buffers can be realized in XRAM, and interrupts need only be serviced if the larger XRAM buffers fill or empty. www.onsemi.com AX8052F131 Transmitter HDLC Mode Note: HDLC mode follows High-Level Data Link Control (HDLC, ISO 13239) protocol. HDLC Mode is the main framing mode of the AX8052F131. In this mode, the AX8052F131 performs automatic packet delimiting, and optional packet correctness check by inserting and checking a cyclic redundancy check (CRC) field. The packet structure is given in the following table. Flag Address Control Information FCS Flag 8 bit 8 bit Variable length, 0 or more bits in multiples of 8 16 / 32 bit 8 bit 8 or 16 bit HDLC packets are delimited with flag sequences of content 0x7E. In AX8052F131 the meaning of address and control is user defined. The Frame Check Sequence (FCS) can be programmed to be CRC-CCITT, CRC-16 or CRC-32. For details on implementing a HDLC communication see the AX5031 Programming Manual. RAW Mode In Raw mode, the AX8052F131 does not perform any packet delimiting or byte synchronization. It simply serializes transmit bytes. This mode is ideal for implementing legacy protocols in software. 802.15.4 (ZigBee) DSSS 802.15.4 uses binary phase shift keying (PSK) with 300 kbit/s (868 MHz band) or 600 kbit/s (915 MHz band) on the radio. The usable bit rate is only a 15th of the radio bit rate, however. A spreading function in the transmitter expands the user bit rate by a factor of 15, to make the transmission more robust. In 802.15.4 mode, the AX8052F131 framing unit performs the spreading function according to the 802.15.4 specification. The 802.15.4 is a universal DSSS mode, which can be used with any modulation or datarate as long as it does not violate the maximum data rate of the modulation being used. Therefore the maximum DSSS data rate is 16 kbps for FSK and 40 kbps for ASK and PSK. www.onsemi.com AX8052F131 37 38 Transmitter 6.5. Modulator Depending on the transmitter settings the modulator generates various inputs for the PA: Modulation Bit = 0 Bit = 1 Main Lobe Bandwidth Max. Bitrate ASK PA off PA on BW=BITRATE 2000kBit/s FSK / MSK /GFSK ∆f=-fdeviation ∆f=+fdeviation BW=(1+h) ⋅BITRATE 350kBit/s PSK ∆Φ=00 ∆Φ=1800 BW=BITRATE 2000kBit/s h = modulation index. It is the ratio of the deviation compared to the bit-rate; fdeviation= 0.5⋅h⋅BITRATE, AX8052F131 can demodulate signals with h < 32. ASK = amplitude shift keying FSK = frequency shift keying MSK = minimum shift keying; MSK is a special case of FSK, where h = 0.5, and therefore fdeviation = 0.25⋅BITRATE; the advantage of MSK over FSK is that it can be demodulated more robustly. PSK = phase shift keying OQPSK = offset quadrature shift keying. The AX8052F131 supports OQPSK. However, unless compatibility to an existing system is required, MSK should be preferred. 4-FSK = four frequencies are used to transmit two bits simultaneously during each symbol Modulation Symbol = 00 Symbol = 01 Symbol = 10 Symbol = 11 Max. Bitrate 4-FSK ∆f = -3⋅fdeviation ∆f = -fdeviation ∆f = +fdeviation ∆f = +3⋅fdeviation 400 kBit/s All modulation schemes are binary. www.onsemi.com AX8052F131 Transmitter 6.6. PWRMODE Register The AX8052F131 transmitter features its own independent power management, independent from the microcontroller. While the microcontroller power mode is controlled through the PCON register, the AX5031_PWRMODE register controls which parts of the transmitter are operating. AX5031_PWRMODE register Name 0000 POWERDOWN All digital and analog transmitter functions, except the register file, are disabled. VREG is reduced to conserve leakage power. The registers are still accessible. 0100 VREGON All digital and analog transmitter functions, except the register file, are disabled. VREG, however is at its nominal value for operation, and all registers are accessible. 0101 STANDBY The crystal oscillator is powered on; the transmitter is off. 1100 SYNTHTX The synthesizer is running on the transmit frequency. The transmitter is still off. This mode is used to let the synthesizer settle on the correct frequency for transmit. FULLTX Synthesizer and transmitter are running. Do not switch into this mode before the synthesizer has completely settled on the transmit frequency (in SYNTHTX mode), otherwise spurious spectral transmissions will occur. 1101 Description A typical AX5031_PWRMODE sequence for a transmit session: Step PWRMODE[3:0] Remarks 1 POWERDOWN 2 STANDBY The settling time is dominated by the crystal used, typical value 3ms. 3 SYNTHTX The synthesizer settling time is 5 – 50 μs depending on settings, see section AC Characteristics 4 FULLTX Data transmission 5 POWERDOWN www.onsemi.com AX8052F131 39 Application Information 7. Application Information Connecting to Debug Adapter Jumper JP1 VDD_IO 100pF 4.7uF PA0 VDD_IO PA1 PA2 PA3 PA4 PA5 32 kHz XTAL PA6 PA7 PC7 GND 16 MHz XTAL VREG 1uF CLK16P 1 GND CLK16N 2 RESET_N VDDA 3 DBG_EN GND 4 PB7 AX8052F131 ANTP 5 PB6 ANTN 6 PB5 GND PB4 VDDA PB3 DBG_RT_N GND DBG_CLK DBG_DATA GND DBG_VDD Debug adapter connector PB2 PB1 PB0 PC0 PC1 PC2 PC3 T1 SYSCLK T2 T1 DBG_EN 7 8 SYSCLK 40 Figure 9 Typical application diagram with connection to the debug adapter Short Jumper JP1-1 if it is desired to supply the target board from the Debug Adapter (50mA max). Connect the bottom exposed pad of the AX8052F131 to ground. If the debugger is not running, PB6 and PB7 are not driven by the Debug Adapter. If the debugger is running, the PB6 and PB7 values that the software reads may be set using the Pin Emulation feature of the debugger. PB3 is driven by the debugger only to bring the AX8052F131 out of Deep Sleep. It is high impedance otherwise. The 32 kHz crystal is optional, the fast crystal at pins CLK16N and CLK16P is used as reference frequency for the RF RX/TX. Crystal load capacitances should be chosen according to the crystal’s datasheet. At pins CLK16N and CLK16P they the internal programmable capacitors may be used, at pins PA3 and PA4 capacitors must be connected externally. It is mandatory to add 1µF (low ESR) between VREG and GND. Decoupling capacitors are not all drawn. It is recommended to add 100nF decoupling capacitor for www.onsemi.com AX8052F131 Application Information 41 every VDDA and VDD_IO pin. In order to reduce noise on the antenna inputs it is recommended to add 27 pF on the VDD pins close to the antenna interface. The AX8052F131 has an integrated voltage regulator for the analog supply voltages, which generates a stable supply voltage VREG from the voltage applied at VDD_IO. Use VREG to supply all the VDDA supply pins and also to DC power to the pins ANTP and ANTN. 7.1. Antenna Interface Circuitry The ANTP and ANTN pins provide RF output from the PA when AX8052F131 is in transmitting mode. A small antenna can be connected with an optional translation network. The network must provide DC power to the PA. A biasing to VREG is necessary. Beside biasing and impedance matching, the proposed networks also provide low pass filtering to limit spurious emission. Single-Ended Antenna Interface VREG CC1 LC1 CM1 CB1 LT1 CT1 LB2 LF1 CF1 IC Antenna Pins LT2 CT2 LC2 50Ω singleended equipment or antenna CB2 CM2 LB1 CC2 CF2 Optional filter stage to suppress TX harmonics VREG Figure 10 Structure of the antenna interface to 50 Ω single-ended equipment or antenna Frequency Band LC1,2 [nH] CC1,2 [pF] LT1,2 [nH] CT1,2 [pF] CM1,2 [pF] 868 / 915 MHz 68 1.2 12 18 2.4 433 MHz 120 2.7 39 7.5 6.0 www.onsemi.com LB1,2 [nH] CB1,2 [pF] LF1 [nH] CF1,2 [pF] 12 2.7 0 OHM N.C. 27 5.2 0 OHM N.C AX8052F131 42 QFN40 Package Information 8. QFN40 Package Information 8.1. Package Outline QFN40 ON AX8052F131-V AWLYYWW Package V YY WW XXXX marking silicon version packaging year packaging week silicon code Notes 1. 2. 3. 4. 5. 6. 7. 8. 9. ‘e’ represents the basic terminal pitch Datum ‘C’ is the mounting surface with which the package is in contact. ‘3’ specifies the vertical shift of the flat part of each terminal from the mounting surface. Dimension ‘A’ includes package warpage. Dimension ‘b’ applies to the metallised terminal and is measured between 0.15 to 0.30 mm from the terminal tip. If the terminal has the optional radius on the other end of the terminal, the dimension ‘b’ should not be measured in the radius are Package dimension take reference from JEDEC MO-220 AWLYYWW is the packaging lot code V is the device version RoHS www.onsemi.com AX8052F131 QFN40 Package Information 8.2. QFN40 Soldering Profile Preheat Reflow tp Tp Temperature Cooling T tL L TsMAX TsMIN ts 25°C t25° to Peak Time Profile Feature Pb-Free Process Average Ramp-Up Rate 3 °C/sec max. Preheat Preheat Temperature Min TsMIN 150°C Temperature Max TsMAX 200°C Time (TsMIN to TsMAX) ts 60 – 180 sec Time 25°C to Peak Temperature T25 ° to Peak 8 min max. Liquidus Temperature TL 217°C Time over Liquidus Temperature tL 60 – 150 sec Peak Temperature tp 260°C Time within 5°C of actual Peak Temperature Tp 20 – 40 sec Reflow Phase Cooling Phase Ramp-down rate 6°C/sec max. Notes: All temperatures refer to the top side of the package, measured on the package body surface. www.onsemi.com AX8052F131 43 44 QFN40 Package Information 8.3. QFN40 Recommended Pad Layout 1. PCB land and solder masking recommendations are shown in Figure 11. A= Clearance from PCB thermal pad to solder mask opening, 0.0635 mm minimum B = Clearance from edge of PCB thermal pad to PCB land, 0.2 mm minimum C = Clearance from PCB land edge to solder mask opening to be as tight as possible to ensure that some solder mask remains between PCB pads D = PCB land length = QFN solder pad length + 0.1mm E = PCB land width = QFN solder pad width + 0.1 mm Figure 11 PCB land and solder mask recommendations 2. 3. Thermal vias should be used on the PCB thermal pad (middle ground pad) to improve thermal conductivity from the device to a copper ground plane area on the reverse side of the printed circuit board. The number of vias depends on the package thermal requirements, as determined by thermal simulation or actual testing. Increasing the number of vias through the printed circuit board will improve the thermal conductivity to the reverse side ground plane and external heat sink. In general, adding more metal through the PC board under the IC will improve operational heat transfer, but will require careful attention to uniform heating of the board during assembly. 8.4. Assembly Process Stencil Design & Solder Paste Application 1. Stainless steel stencils are recommended for solder paste application. 2. A stencil thickness of 0.125 – 0.150 mm (5 – 6 mils) is recommended for screening. 3. For the PCB thermal pad, solder paste should be printed on the PCB by designing a stencil with an array of smaller openings that sum to 50% of the QFN exposed pad area. Solder paste should be applied through an array of squares (or circles) as shown in Figure 12. 4. The aperture opening for the signal pads should be between 50-80% of the QFN pad area as shown in Figure 13. 5. Optionally, for better solder paste release, the aperture walls should be trapezoidal and the corners rounded. 6. The fine pitch of the IC leads requires accurate alignment of the stencil and the printed circuit board. The stencil and printed circuit assembly should be aligned to within + 1 mil prior to application of the solder paste. 7. No-clean flux is recommended since flux from underneath the thermal pad will be difficult to clean if water-soluble flux is used. www.onsemi.com AX8052F131 QFN40 Package Information Figure 12 Solder paste application on exposed pad Minimum 50% coverage 62% coverage Maximum 80% coverage Figure 13 Solder paste application on pins www.onsemi.com AX8052F131 45 46 Device Versions 9. Device Versions Device Marking AX8052 Version AX5031 Version AX8052F131-2 1C 1 www.onsemi.com AX8052F131