Rainbow Electronics ATA5812 User Manual
Features, Applications, Benefits

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
Document Outline
- Features
- General Description
- Pin Description
- Typical Key Fob or Sensor Application with 1 Battery
- Typical Car or Sensor Base-station Application
- Typical Key Fob Application, 2 Batteries
- RF Transceiver
- Low-IF Receiver
- Input Matching at RF_IN
- Sensitivity versus Supply Voltage, Temperature and Frequency Offset
- Frequency Accuracy of the Crystals
- RX Supply Current versus Temperature and Supply Voltage
- Blocking, Selectivity
- Inband Disturbers, Data Filter, Quasi Peak Detector, Data Slicer
- DEM_OUT Output
- RSSI Output
- Frequency Synthesizer
- FSK/ASK Transmission
- Output Power Setting and PA Matching at RF_OUT
- Output Power and TX Supply Current versus Supply Voltage and Temperature
- RX/TX Switch
- Matching Network in TX Mode
- Matching Network in RX Mode
- XTO
- Power Supply
- Microcontroller Interface
- Digital Control Logic
- Transceiver Configuration
- Operation Modes
- Absolute Maximum Ratings
- Thermal Resistance
- Electrical Characteristics: General
- Electrical Characteristic: 1-Battery Application
- Electrical Characteristics: 2-Battery Application
- Electrical Characteristics: Car Application
- Digital Timing Characteristics
- Digital Port Characteristics
- Ordering Information
- Package Information
- Table of Contents