ATA5428 UHF ASK/FSK Transceiver DATASHEET Features ● Multi channel half-duplex transceiver with approximately ±2.5MHz programmable tuning range ● High FSK sensitivity: –106dBm at 20Kbit/s/–109.5dBm at 2.4Kbit/s (433.92MHz) ● High ASK sensitivity: –112.5dBm at 10Kbit/s/–116.5dBm at 2.4Kbit/s (433.92MHz) ● Low supply current: 10.5mA in RX and TX Mode (3V/TX with 5dBm) ● Data Rate: 1 to 20Kbit/s Manchester FSK, 1 to 10Kbit/s Manchester ASK ● ASK/FSK receiver uses a low-IF architecture with high selectivity, blocking, and low intermodulation (typical blocking 55dB at ±750kHz/61dB at ±1.5MHz and 70dB at ±10MHz, system I1dBCP = –30dBm/system IIP3 = –20dBm) ● 226kHz/237kHz IF frequency with 30dB image rejection and 170kHz usable IF bandwidth ● Transmitter uses closed loop fractional-N synthesizer for FSK modulation with a high PLL bandwidth and an excellent isolation between PLL/VCO and PA ● Tolerances of XTAL compensated by fractional-N synthesizer with 800Hz 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 max.500kBit/s ● Configurable self polling and RX/TX protocol handling with FIFO-RAM buffering of received and transmitted data ● Five push button inputs and one wake-up input are active in power-down mode ● integrated XTAL capacitors ● PA efficiency: up to 38% (433.92MHz/10dBm/3V) ● Low in-band sensitivity change of typically ±1.8dB within ±58kHz 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, PLL loop filter and full support of multi-channel operation with arbitrary channel distance due to fractional-N synthesizer ● Sophisticated threshold control and quasi-peak detector circuit in the data slicer ● Power management via different operation modes ● 433.92MHz and 868.3MHz without external VCO and PLL components ● Inductive supply with voltage regulator if battery is empty (AUX mode) ● Efficient XTO start-up circuit (> –1.5kΩ worst case real start-up impedance) ● Changing of modulation type ASK/FSK and data rate without component changes...

General Description The Atmel® ATA5428 is a highly integrated UHF ASK/FSK multi-channel half-duplex transceiver with low power consumption supplied in a small 7 x 7mm QFN48 package. The receive part is built as a fully integrated low-IF receiver, whereas direct PLL modulation with the fractional-N synthesizer is used for FSK transmission and switching of the power amplifier for ASK transmission. The device supports data rates of 1Kbit/s to 20Kbit/s (FSK) and 1Kbit/s to 10Kbit/s (ASK) in Manchester, Bi-phase and other codes in transparent mode. The ATA5428 can be used in the 431.5MHz to 436.5MHz...

Symbol Function 433_N868 Selects RF input/output frequency range R_PWR Resistor to adjust output power PWR_H Pin to select output power AVCC Blocking of the analog voltage supply VS2 Power supply input for voltage range 4.4V to 6.6V VS1 Power supply input for voltage range 2.4V to 3.6V VAUX Auxiliary supply voltage input

Test input, at GND during operation Blocking of the digital voltage supply Output voltage power supply for external devices Test input, at GND during operation Reference crystal Reference crystal Interrupt request Clock output to connect a microcontroller Serial data out/transparent mode data out Switch pin to decouple LNA in TX mode Key input 5 (can also be used to switch on the system (active low)) Key input 4 (can also be used to switch on the system (active low)) Key input 3 (can also be used to switch on the system (active low)) Key input 2 (can also be used to switch on the system (active...

Figure 1-3. Block Diagram AVCC Digital Control Logic Power Supply Frontend Enable RX/TX Switch TX_DATA (FSK) Switches Regulators Wake-up Reset Fractional-N Frequency Synthesizer Signal Processing (Mixer IF Filter IF Amplifier FSK/ASK Demodulator, Data Filter Data Slicer) TX/RX - Data Buffer Control Register Status Register Polling Circuit Bit-check Logic Microcontroller Interface SDI_TMDI SDO_TMDO

Application Circuits Typical Remote Control Unit Application with 1 Li Battery (3V) Figure 2-1 shows a typical 433.92MHz Remote Control Unit application with one battery. The external components are 11 capacitors, 1 resistor, 2 inductors and a crystal. C1 to C4 are 68nF voltage supply blocking capacitors. C5 is a 10nF supply blocking capacitor. C6 is a 15nF fixed capacitor used for the internal quasi-peak detector and for the high-pass frequency of the data filter. C7 to C11 are RF matching capacitors in the range of 1pF to 33pF. L1 is a matching inductor of about 5.6nH to 56nH. L2 is a feed...

Typical Base-station Application (5V) Figure 2.2 shows a typical 433.92MHz VCC = 4.75V to 5.25V Base-station Application (5V). The external components are 12 capacitors, 1 resistor, 4 inductors, a SAW filter, and a crystal. C1 and C3 to C4 are 68nF voltage supply blocking capacitors. C2 and C12 are 2.2µF supply blocking capacitors for the internal voltage regulators. C5 is a 10nF supply blocking capacitor. C6 is a 15 nF fixed capacitor used for the internal quasi-peak detector and for the high-pass frequency of the data filter. C7 to C11 are RF matching capacitors in the range of 1pF to 33pF....

Typical Remote Control Unit Application, 2 Li Batteries (6V) Figure 2-3 shows a typical 433.92Hz 2 Li battery Remote Control Unit application. The external components are 11 capacitors, 1 resistor, 2 inductors and a crystal. C1 and C4 are 68nF voltage supply blocking capacitors. C2 and C3 are 2.2µF supply blocking capacitors for the internal voltage regulators. C5 is a 10nF supply blocking capacitor. C6 is a 15nF fixed capacitor used for the internal quasi-peak detector and for the high-pass frequency of the data filter. C7 to C11 are RF matching capacitors in the range of 1pF to 33pF. L1 is...