TH712 21 27 to 930MHz FSK/FM/ASK Transceiver Features Single chip solution with only a few external 3wire bus serial control interface components FSK/ASK mode selection Stand-alone fixed-frequency user mode FSK for digital data or FM for analog signal Programmable multi-channel user mode reception Low current consumption in active mode and RSSI output for signal strength indication and very low standby current ASK reception PLL-stabilized RF VCO (LO) with internal Peak detector for ASK detection varactor diode Switchable LNA gain for improved dynamic Lock detect output in programmable range user mode Automatic PA turn-on after PLL lock On-chip AFC for extended input frequency ASK modulation achieved by PA on/off keying acceptance range 32-pin Quad Flat Lead Package (QFN) Ordering Code Product Code Temperature Code Package Code Option Code Packing Form Code TH71221 E LQ BAA-000 RE TH71221 E LQ BAA-000 TU Legend: Temperature Code: E for Temperature Range -40C to 85C Package Code: LQ for QFN, Packing Form: RE for Reel, TU for Tube Ordering example: TH71221ELQ-BAA-000-RE Application Examples Pin Description bottom top General bi-directional half duplex digital data RF signaling or analog signal communication Remote Keyless Entry (RKE) Low-power telemetry systems IN IFA Alarm and security systems VCC IF LF Wireless access control IN DEM VEE PLL INT2/PDO TNK LO Garage door openers TH71221 INT1 VCC PLL OUT DEM FS1/LD Networking solutions RSSI VEE DIG Active RFID tags OUT DTA FS0/SDEN Remote controls Home and building automation General Description The TH71221 is a single chip FSK/FM/ASK transceiver IC. It is designed to operate in low-power multi- channel programmable or single-channel stand-alone, half-duplex data transmission systems. It can be used for applications in automotive, industrial-scientific-medical (ISM), short range devices (SRD) or similar appli- cations operating in the frequency range of 300 MHz to 930 MHz. In programmable user mode, the trans- ceiver can operate down to 27 MHz by employing an external VCO varactor diode. 39010 071221 Page 1 of 44 Data Sheet Rev. 009 Nov/15 VEE RO OUT MIX RO VEE IF FSK SW IN MIX IN DTA GAIN LNA ASK/FSK OUT LNA VCC DIG VEE LNA IN LNA RE/SCLK OUT PATH712 21 27 to 930MHz FSK/FM/ASK Transceiver Table of Content 1 Theory of Operation ................................................................................................... 4 1.1 General .............................................................................................................................. 4 1.2 Technical Data Overview ................................................................................................... 4 1.3 Note on ASK Operation ...................................................................................................... 4 1.4 Block Diagram .................................................................................................................... 5 1.5 User Mode Features .......................................................................................................... 5 2 Pin Definitions and Descriptions .............................................................................. 6 3 Functional Description ............................................................................................ 10 3.1 PLL Frequency Synthesizer ............................................................................................. 10 3.1.1 Reference Oscillator (XOSC) ..................................................................................................... 11 3.1.2 Reference Divider ...................................................................................................................... 11 3.1.3 Feedback Divider ....................................................................................................................... 11 3.1.4 Frequency Resolution and Operating Frequency ...................................................................... 11 3.1.5 Phase-Frequency Detector ........................................................................................................ 12 3.1.6 Lock Detector ............................................................................................................................. 12 3.1.7 Voltage Controlled Oscillator with external Loop Filter .............................................................. 13 3.1.8 Loop Filter .................................................................................................................................. 13 3.2 Receiver Part ................................................................................................................... 13 3.2.1 LNA ............................................................................................................................................ 14 3.2.2 Mixer .......................................................................................................................................... 14 3.2.3 IF Amplifier ................................................................................................................................. 14 3.2.4 ASK Demodulator ...................................................................................................................... 14 3.2.5 FSK Demodulator ...................................................................................................................... 15 3.3 Transmitter Part ............................................................................................................... 15 3.3.1 Power Amplifier .......................................................................................................................... 15 3.3.2 Output Power Adjustment .......................................................................................................... 16 3.3.3 Modulation Schemes ................................................................................................................. 16 3.3.4 ASK Modulation ......................................................................................................................... 16 3.3.5 FSK Modulation ......................................................................................................................... 17 3.3.6 Crystal Tuning ............................................................................................................................ 17 4 Description of User Modes ...................................................................................... 18 4.1 Stand-alone User Mode Operation ................................................................................... 18 4.1.1 Frequency Selection .................................................................................................................. 18 4.1.2 Operation Mode ......................................................................................................................... 18 4.1.3 Modulation Type ........................................................................................................................ 19 4.1.4 LNA Gain Mode ......................................................................................................................... 19 4.2 Programmable User Mode Operation ............................................................................... 19 4.2.1 Serial Control Interface Description ........................................................................................... 19 5 Register Description ................................................................................................ 20 5.1 Register Overview ............................................................................................................ 21 39010 071221 Page 2 of 44 Data Sheet Rev. 009 Nov/15