AS3977 DB

Data Sheet AS3977 Multi-Channel Narrowband FSK Transmitter Main Characteristics 1 General Description The AS3977 is a low-power fully integrated ETSI, FCC and ARIB 2.0 3.6V power supply compliant FSK transmitter capable of operating at any ISM Power down current consumption 100 nA (3V, 25C) frequency in the range of 300 to 928 MHz. It is based on a sigma- delta controlled fractional-N synthesizer phase locked loop (PLL) Output power up to +10dBm with fully integrated voltage controlled oscillator (VCO). The power Occupied bandwidth 6 kHz (4.8 kb/s, FFSK, ARIB) amplifier (PA) output is programmable and can deliver power ranging from 20dBm up to +10dBm. An on-chip low drop-out (LDO) -40 to 85C temperature range regulator is available in case an accurate output power independent of voltage supply variation is required. The output signal can be Additional Features shaped using a programmable Gaussian filter to minimize the occupied bandwidth and adjacent channel power. The maximum data rate can be up to 100 kb/s depending on the required filtering. Sigma-Delta controlled fractional-N synthesizer The FSK frequency deviation is programmable up to a maximum of Resolution of synthesizer < 100Hz 64 kHz. Fully integrated PLL The crystal oscillator can handle a wide range of frequencies. For narrow-band applications, a temperature sensor with digital read-out Fully integrated voltage controlled oscillator (VCO) is included that allows compensation of the crystal frequency drift 4kV ESD protection (1.5kV for the Analog pins) due to temperature variation. 12 20 MHz crystal oscillator The AS3977 is connected to an external microcontroller via a bi- On-chip temperature sensor with digital readout for AFC pur- directional digital interface. The device operates at very low current poses consumption with a power supply range from 2.0V to 3.6V and can be powered down when not in use. Fast frequency hopping with predefined channel selection The device is fabricated in austriamicroystems advanced 0.35m Microcontroller clock output to save addition crystal SiGe-BiCMOS technology. Constant output power over battery life time Integrated Manchester coder 2 Key Features Digital lock detector Fully integrated UHF transmitter Low drop-out regulator Compliant to ETSI EN 300-220, FCC CFR47 part 15 and ARIB Bi-directional serial interface STD-T67 Low Power Down Mode current consumption Multi-channel with narrow bandwidth 300 928 MHz operating frequency range (ISM) 3 Applications Filtered FSK The AS3977 is suitable for Remote keyless entry systems, Short Data rate up to 100 kb/s range radio data transmission, Domestic and consumer remote control units, Cordless alarm systems, Remote metering, and Low FSK deviation programmable up to 64kHz power telemetry. Extremely low power consumption www.austriamicrosystems.com/AS3977 Revision 3.6 1 - 47SDI interface/ Con- trol Interface AS3977 Data Sheet - Applications Figure 1. AS3977 Block Diagram VCCPLL VCC PA VDD VREGDIG U Phase Charge Loop detector pump filter VCO XTAL IN VREGRF U Q 4 XTAL OUT Pre Out CLK Gen Pre Driving Baudrate Gen. Amplifier P amplifier N MC CLK T PA Out Deviation RF Band RFchannel Synthesizer RF-power Data sync. Temp DATA I/O RF-power RF-band CLOCK RFchannel ENABLE LPR GND VSS GND exposed paddle www.austriamicrosystems.com/AS3977 Revision 3.6 2 - 47