ST25RU3993 RAIN RFID single chip reader EPC Class1 Gen2 compatible Datasheet - production data Description The ST25RU3993 RAIN (UHF) RFID reader device provides multi-protocol support for the 840-960 MHz UHF band compatible with ISO18000-62 & -63, ISO29143 and to GS1s EPC UHF Gen2 air interface protocol. It includes an on-chip VCO and a power amplifier, and offers a complete set of RFID features including dense reader mode (DRM) functionality and support for QFN48 frequency-hopping, low-level transmission coding, low-level decode, data framing and CRC checking. The ST25RU3993 operates at very low-power, Features making it suitable for use in portable and battery- powered equipment such as mobile phones. Supply voltage range 3.0 to 3.6 V Limited operation possible down to 2.7 V Packaged in a 7x7 mm QFN, the ST25RU3993 is able to deliver very high sensitivity and provides Maximum PA supply voltage 4.3 V high immunity against the effects of antenna Peripheral I/O supply range 1.65 to 5.5 V reflection and self-jamming. This is critical in Protocol support for: mobile and embedded applications, in which ISO 18000-6C (EPC Class1 Gen2) antenna design is often compromised by cost or ISO 29143 (Air interface for mobile RFID) size constraints. High sensitivity enables the end- products to achieve their required read range ISO 18000-6A/B through direct mode while using a simpler and cheaper antenna, thus DRM: 250 kHz and 320 kHz filters for M4 and reducing overall system cost. M8 Thanks to its high level of integration, the Integrated supply regulators ST25RU3993 requires only an external 8-bit Frequency hopping support microcontroller to create a complete RFID reader ASK or PR-ASK modulation system, thus eliminating the need for a complex RFID co-processor. Automatic I/Q selection Phase bit for tag tracking with 8-bit linear RSSI Temperature range: -40 C to 85 C 48-pin QFN (7x7x0.9 mm) package Tag read rates of up to 700* tags/s (16-bit tag EPC length) April 2021 DS11840 Rev 11 1/90 This is information on a product in full production. www.st.comContents ST25RU3993 Contents 1 Description . 9 1.1 Block diagram . 9 2 Functional overview 10 2.1 Power supply 12 2.1.1 Main regulators . 12 2.1.2 Internal PA supply regulator 12 2.1.3 Periphery communication supply 12 2.1.4 Automatic power supply level setting . 12 2.1.5 Power modes . 13 2.2 Host communication . 14 2.2.1 Writing to registers . 16 2.2.2 Reading from registers . 17 2.2.3 Direct commands 18 2.2.4 SPI interface timing 22 2.2.5 CLSYS output 24 2.2.6 IO signal level and output characteristics . 24 2.2.7 OAD, OAD2 outputs . 25 2.3 PLL and VCO section 25 2.3.1 Voltage controlled oscillator 26 2.3.2 PLL prescaler and main divider . 26 2.3.3 PLL reference frequency 27 2.3.4 Reference frequency source . 27 2.3.5 Phase-frequency detector and charge pump . 27 2.3.6 Loop filter 27 2.3.7 Frequency hopping commands . 27 2.3.8 PLL start-up and frequency hopping . 28 2.4 Device status control 28 2.5 Protocol control 28 2.6 Transmission section 29 2.6.1 Tx data handling and coding . 29 2.6.2 Tx shape circuitry 29 2.6.3 Local oscillator (LO) path 30 2.6.4 Modulator 30 2/90 DS11840 Rev 11