STS1TX Low data-rate, low power sub-1GHz transmitter Datasheet - production data QFN20 4x4 mm RoHS package Operating temperature range from -40 C to 85 C Applications QFN20 AMR (automatic meter reading) Home and building automation WSN (wireless sensors network) Features Industrial monitoring and control Frequency bands: 150-174 MHz, 300-348 Wireless fire and security alarm systems MHz, 387-470 MHz, 779-956 MHz Point-to-point wireless link Modulation schemes: 2-FSK, GFSK, MSK, GMSK, OOK, and ASK Table 1. Device summary Air data rate from 1 to 500 kbps Order code Package Packing Very low power consumption (21 mA TX at +11 dBm) STS1TXQTR QFN20 Tape and reel Programmable channel spacing (12.5 kHz min.) Programmable output power up to +16 dBm Fast startup and frequency synthesizer settling time (6 s) Integrated temperature sensor Battery indicator and low battery detector TX FIFO buffer (96 bytes each) Configurability via SPI interface AES 128-bit encryption co-processor Fully integrated ultra low power RC oscillator Wakeup on internal timer and on external event Flexible packet length with dynamic payload length Automatic CRC handling FEC with interleaving Whitening of data Wireless M-BUS, EN 300 220, FCC CFR47 15 (15.205, 15.209, 15.231, 15.247, 15.249), and ARIB STD T-67, T93, T-108 compliant August 2013 DocID025109 Rev 1 1/70 This is information on a product in full production. www.st.com 70Contents STS1TX Contents 1 Description . 5 2 Introduction 6 3 Typical application diagram and pin description 7 3.1 Typical application diagram 7 4 Pinout 10 5 Absolute maximum ratings and thermal data . 11 6 Characteristics 12 6.1 General characteristics . 12 6.2 Electrical specifications 12 6.2.1 Electrical characteristics 12 6.2.2 Digital SPI . 13 6.2.3 RF transmitter 14 6.2.4 Crystal oscillator 18 6.2.5 Sensors . 20 7 Operating modes . 21 7.1 Reset sequence 23 7.2 Timer usage . 24 8 Block description 26 8.1 Power management . 26 8.1.1 Switching frequency 26 8.2 Power-on-reset (POR) . 26 8.3 Low battery indicator 26 8.4 Voltage reference . 27 8.5 Oscillator and RF synthesizer . 27 8.6 RCO: features and calibration . 30 8.6.1 RC oscillator calibration . 31 8.7 Transmitter 31 2/70 DocID025109 Rev 1