Rainbow Electronics ATA5812 - Manual

Rev. 4689B–RKE–04/04
Features
• High FSK Sensitivity: -106 dBm at 20 kBaud/-109.5 dBm at 2.4 kBaud (433.92 MHz)
• High ASK Sensitivity: -112.5 dBm at 10 kBaud/-116.5 dBm at 2.4 kBaud (433.92 MHz)
• Low Supply Current: 10.5 mA in RX and TX Mode (3 V/TX with 5 dBm)
• Data Rate 1 to 20 kBaud Manchester FSK, 1 to 10 kBaud Manchester ASK
• ASK/FSK Receiver Uses a Low-IF Architecture with High Selectivity, Blocking and Low
Intermodulation (Typical Blocking 55 dB at ±750 kHz/61 dB at ±1.5 MHz and
70 dB at ±10 MHz, System I1dBCP = -30 dBm/System IIP3 = -20 dBm)
• 226 kHz IF Frequency with 30 dB Image Rejection and 170 kHz Usable IF Bandwidth
• Transmitter Uses Closed Loop Fractional-N Synthesizer for FSK Modulation with a
High PLL Bandwidth and an Excellent Isolation between PLL and PA
• Tolerances of XTAL Compensated by Fractional-N Synthesizer with 800 Hz RF
Resolution
• Integrated RX/TX-Switch, Single-ended RF Input and Output
• RSSI (Received Signal Strength Indicator)
• Communication to Microcontroller with SPI Interface Working at Maximum 500 kBit/s
• Configurable Self Polling and RX/TX Protocol Handling with FIFO-RAM Buffering of
Received and Transmitted Data
• 5 Push Button Inputs and One Wake-up Input are Active in Power-down Mode
• Integrated XTAL Capacitors
• PA Efficiency: up to 38% (433 MHz/10 dBm/3 V)
• Low Inband Sensitivity Change of Typically ±1.8 dB within ±58 kHz Center Frequency
Change in the Complete Temperature and Supply Voltage Range
• Supply Voltage Switch, Supply Voltage Regulator, Reset Generation, Clock/Interrupt
Generation and Low Battery Indicator for Microcontroller
• Fully Integrated PLL with Low Phase Noise VCO and PLL Loop Filter
• Sophisticated Threshold Control and Quasi Peak Detector Circuit in the Data Slicer
• Power Management via Different Operation Modes
• 433.92 MHz, 868.3 MHz and 315 MHz without External VCO and PLL Components
• Inductive Supply with Voltage Regulator if Battery is Empty (AUX Mode)
• Efficient XTO Start-up Circuit (> -1.5 k
Ω
Worst Case Start Impedance)
• Changing of Modulation Type ASK/FSK and Data Rate without Component Changes
• Minimal External Circuitry Requirements for Complete System Solution
• Adjustable Output Power: 0 to 10 dBm Adjusted and Stabilized with External Resistor
• ESD Protection at all Pins (2 kV HBM, 200 V MM)
• Supply Voltage Range: 2.4 V to 3.6 V or 4.4 V to 6.6 V
• Temperature Range: -40°C to +105°C
• Small 7
×
7 mm QFN48 Package
Applications
• Automotive Keyless Entry and Passive Entry Go Systems
• Access Control Systems
• Remote Control Systems
• Alarm and Telemetry Systems
• Energy Metering
• Home Automation
Benefits
• No SAW Device Needed in Key Fob Designs to Meet Automotive Specifications
• Low System Cost Due to Very High System Integration Level
• Only One Crystal Needed in System
• Less Demanding Specification for the Microcontroller Due to Handling of Power-down
Mode, Delivering of Clock, Reset, Low Battery Indication and Complete Handling of
Receive/Transmit Protocol and Polling
• Single-ended Design with High Isolation of PLL/VCO from PA and the Power Supply
Allows a Loop Antenna in the Key Fob to Surround the Whole Application
UHF ASK/FSK
Transceiver
ATA5811
ATA5812
Preliminary