1. 1 SmartRF CC400 / CC900 Single Chip High Performance RF Transceivers Peder Martin Evjen, M.Sc.E.E Field Application Engineer

2. 2 Applications overview n UHF wireless FSK data transmitters and receivers n LPD, Low Power Devices n SRD, Short Range Devices n ISM, Industrial - Scientific - Medicine n 433 and 418 MHz SRD band systems n 868MHz European SRD band n 260 - 470 US ISM band n 902-928 US ISM band

3. 3 Applications overview n Keyless entry with acknowledgement n Telemetry / remote metering of; l electricity, water, gas l temperature, pressure l environment and air quality n Smart House applications l lights, heat, alarms, comfort, electrical equipment n Alarm and security systems n Remote Tagging (RF Tag) n Industrial Remote Controls l lifts, cranes, industrial equipment n “Intelligent” toys

4. 4 Radio transmission system n CC400/900: One-chip RF transceiver n FSK modulation (superior to ASK) n Up to 9.6kbps (19.2kbaud) Data source Micro controller RF transceiver NRZ (De)coding Manchester (De)modulation FSK

5. 5 CC400/CC900 RF transceiver n Three-wire control interface n Data in/out (bi-directional) n RF antenna in/out DIO PDATA CLOCK STROBE RF

6. 6 Block diagram

7. 7 Receiver features n Low noise front end (3dB noise figure) n High sensitivity CC400: -112dBm @ 1.2kbps,BER=10 -3 CC900: -110dBm @ 1.2kbps,BER=10 -3 n Fully integrated IF stage, no external filters needed (optional ext. 455kHz) n Selectable IF frequency (60/200/455kHz) n Fully integrated FSK demodulator, no external ceramic resonator needed n Data rate 0.3 - 9.6 kbps

8. 8 Transmitter features n Integrated power amplifier - CC400: -5 to 14dBm (25mW) - CC900: -20 to 4dBm (2.5mW) n Programmable output power in 1dB steps n Fully integrated FSK modulator with programmable deviation (1-50 kHz) n Internal RX/TX switch

9. 9 Synthesiser features n Cover 300-500 MHz (CC400) 800-1000 MHz (CC900) n Very fine frequency resolution: l CC400: 5 kHz, CC900: 250 Hz n Free choice crystal frequency (4-13 MHz) n External loop filter for flexibility (optimise to data-rate) n External VCO tank for flexibility n PLL lock signal

10. 10 Chip features n Small package SSOP-28 n Low supply voltage (2.7-3.3 V) n Very low power-down/standby current typical 0.2  A n Few external components n Easy to use 3-wire control bus for configuration

11. 11 Radio range n CC400: >2000 m n CC900: >500 m n 10dBm, quarter wave antenna, 1.2kbps n Key issues: l Sensitivity l Output power l Antenna solution l Interferers / noise n 6dB ~ twice the distance

12. 12 Data interface - DIO pin n Bi-directional data pin (TX:in, RX:out) n Manchester code (a.k.a. bi-phase-level coding) - no DC component - timing information n Final data decision by micro-controller - code available

13. 13 Transmit operation n FSK modulation frequencyfcFc-dfFc+df DIO=low DIO=high Frequency separation = 2 x df

14. 14 Receive operation n Mixing and FSK demodulation Freq. fcFc-dfFc+df DIO=low DIO=high Frequency separation = 2 x df Frequency deviation = df IFIF-dfIF+dfLO Intermediate frequency

15. 15 Configuration n 3-wire serial bus for configuration n 8 control registers of 13 bits each n 3 bit address n Totally 16bits x 8registers = 128 bits n Full configuration in 64  s (at 2MHz) n Configuration data generated by SmartRF Studio (software) -no bit trixing

16. 16 How to generate the configuration data n SmartRF Studio makes it easy: n Enter system parameters - carrier frequency - frequency seperation - IF frequency etc. n ‘File’ - ‘Print registers to file’ n A file containing all necessary configuration data is generated

17. 17 Print-out example RX mode: FrameData (hex) 000002A 001030B 0020141 003051F 0040A00 0051A03 0060B6C 0070040 TX mode: FrameData (hex) 000082A 001030B 0020141 0030457 0040A0A 0051A03 0060B6C 0070040 RX Precharge mode: FrameData (hex) 000002A 001030B 0020141 003051F 0040A00 0051A03 0060B6C 0070248 PD osc. on mode: FrameData (hex) 000102A 001030B 0020141 003051F 0040A00 0051A03 0060B6C 0070040 PD osc. off mode: FrameData (hex) 000102A 001030B 0020151 003051F 0040A00 0051A03 0060B6C 0070040

18. 18 3-wire serial interface n Up to 2MHz clock frequency n 3 bit register address sent first n MSB of data sent first

19. 19 Wiring up the circuit, CC400

20. 20 Wiring up the circuit, CC900

21. 21 External components n Crystal (tolerance, drift, ageing, load) n Input/output matching network - see SmartRF Studio n PLL loop filter (data rate) - see SmartRF Studio n VCO (voltage controlled oscillator) tank l Inductor Q, varactor tuning range n De-coupling and power filtering

22. 22 Optional components n External 455kHz ceramic IF filter n RF filter - LC filter (ref. data sheet) - SAW filter

23. 23 Critical components n VCO inductor should be “good Q” n Murata LQN21A or Coilcraft HQ-series n VCO capacitors tolerance n Varactor sensitivity and Q n Crystal tolerance, drift and ageing

24. 24 Crystal oscillator n RF frequency accuracy ~ crystal accuracy n Crystal specification: l Crystal tolerance l Crystal temperature drift (temp. range) l Crystal pulling (loading sensitivity) l Crystal load capacitance

25. 25 Crystal load capacitance n Total capacitance seen from crystal C151C161 C paracitic

26. 26 Temperature compensation n 25kHz spacing in 868MHz band require <2.5ppm frequency accuracy n Very fine step synthesiser: 250 Hz n Crystal temperature drift compensation n External temperature sensor (single wire chips available) n Crystal drift curve must be known n Alternative to TCXO that cost USD 3-5

27. 27 VCO tank tolerances n Resonate frequency ~ component tolerance n +/-5% tolerance ==> 10% tuning range Tuning voltage Frequency 0 312 Tuning sensitivity Tuning range

28. 28 VCO tuning range and sensitivity n Tuning range: l CC400: 60 MHz (14% at 433 MHz) l CC900: 75 MHz (8.6% at 869 MHz) n Tuning sensitivity: l CC400: 20 MHz/V l CC900: 25 MHz/V n Range must account for tolerances n Sensitivity influence PLL loop gain

29. 29 VCO tank n L91 set impedance level 400MHz : 10nH, 900MHz: 3n3H n C91 set VCO gain n C92 set tuning sensitivity n C93 set absolute range n Bits C11:9 set VCO amplifier gain, 000=max, 111=min C91 C92 L91 VAR C93 VCO in V_tune from loop filter

30. 30 IF bandwidth n 60 kHz IF: 40 kHz bandwidth n 200 kHz IF: 200 kHz bandwidth n 455 kHz IF: Depend on ceramic filter n Signal bandwidth (Carson’s rule): l 2 x frequency error (ppm) l Frequency seperation ( 2 x deviation) l 2 x bitrate (Manchester code)

31. 31 Sensitivity, data rate and IF CC400 n 1.2kbps = -112dBm (60kHz IF, 20kHz separation) n 1.2kbps = -107dBm (200kHz IF, 20kHz separation) n 1.2kbps = -108dBm (455kHz external filter, 12kHz separation) n 9.6kbps = -105dBm (60kHz IF, 30kHz separation) n 9.6kbps = -102dBm (200kHz IF, 30kHz separation) n 9.6kbps = -96dBm (455kHz external filter, 20kHz separation)

32. 32 Sensitivity, data rate and IF CC900 n 1.2kbps = -110dBm (60kHz IF, 20kHz separation) n 1.2kbps = -107dBm (200kHz IF, 20kHz separation)

33. 33 25 kHz channel operation n EN 300220: ACP < -37dBm n Narrow loop filter n Low data rate (1.2kbps) n Low separation / deviation (2.5-10kHz) n Lower output power until requirement is met n Test receiver for measurements of ACP for correct bandwidth

34. 34 RX precharging n Use precharging to reduce receiver turn-on time (controls time-constant in demodulator data slicer) n Configure CC400/CC900 to RX with precharging n Wait for ca 5 bit periods n Configure CC400/CC900 to RX

35. 35 RX precharging

36. 36 Input/output match n See CC400DK user manual appendix n For CC900 the TX is not tuned (choke) n Antenna should be matched to 50 Ohm

37. 37 SAW filter n If SAW is used in both RX and TX the output power should not be >0dBm n Use external RX/TX switch and SAW only in RX path

38. 38 Increasing output power n CC900 has max 4dBm n Insert external amplifier (GaAs, SiGe) n GaAs / PIN diode switch n (insert SAW filter in receive path)

39. 39 Layout n Place VCO in distance from input/output match and XTAL n VCO tank with guard ring (possible to use shield) n No hole in the ground plane (not as in CC400DB) n Ground plane splitting depend on digital circuits around (Most cases a hole plane is preferred) n Two layer circuit board

40. 40 Antenna solutions n Single ended output makes it possible to use a wide range of antennas l Antennas integrated on the PCB F stubs F loops l PCB mounted antennas F helical F ceramic, “splatch” l External antennas F helical, short or full length monopole

41. 41 Feature - Benefit - Advantage

42. 42 Feature - Benefit - Advantage

43. 43 Technical support n FAE: Peder Martin Evjen n Address: Chipcon Components AS, Gaustadalléen 21, N-0349 OSLO, NORWAY n Phone: +47 22 95 83 01 n Fax: +47 22 95 85 46 n Web: http://www.chipcon.com n E-mail: p.m.evjen@chipcon.com