The ADF7020 is a low power, low-IF transceiver designed for operation in the license-free ISM bands at 433MHz, 868MHz and 915MHz. It is suitable for circuit applications that meet either the European ETSI EN-300-220 or the North American FCC, Part 15.247 and 15.249 regulatory standards. It operates from a 2.3 V to 3.6V power supply with programmable output power from -16 to +13dBm in 0.3dBm steps. Its receiver sensitivity is -117.5dBm at 1kbits/s in FSK mode or -110.5dBm at 9.6kbits/s. Power consumption is 20mA in receive mode and 30mA in transmit mode (+10dBm output).
Other features include on-chip VCO (voltage controlled oscillator), Fractional-N PLL, on-chip 7-bit ADC (analog-to-digital converter), digital received signal strength indication (RSSI), temperature sensor and a patent pending fully automatic AFC loop. This allows the ADF7020 to be used with lower tolerance crystals. Its leakage current is < 1uA in power down mode.
This device is suitable for circuit applications that meet the European ETSI-300-220, the North American FCC (Part 15), or the Chinese Short Range Device regulatory standards. A complete transceiver can be built using a small number of external discrete components, making the ADF7020 very suitable for price-sensitive and area-sensitive applications. The transmitter block on the ADF7020 contains a VCO and low noise fractional-N PLL with an output resolution of <1 ppm. This frequency agile PLL allows the ADF7020 to be used in frequency-hopping spread spectrum (FHSS) systems. The VCO operates at twice the fundamental frequency to reduce spurious emissions and frequency-pulling problems.
The transmitter output power is programmable in 0.3 dB steps from −16 dBm to +13 dBm. The transceiver RF frequency and modulation are programmable using a simple 3-wire interface. The device operates with a power supply range of 2.3 V to 3.6 V and can be powered down when not in use.
A low IF architecture is used in the receiver (200 kHz), minimizing power consumption and the external component count and avoiding interference problems at low frequencies. The ADF7020 supports a wide variety of programmable features, including Rx linearity, sensitivity, and IF bandwidth, allowing the user to trade off receiver sensitivity and selectivity against current consumption, depending on the application. The receiver also features a patent-pending automatic frequency control (AFC) loop, allowing the PLL to track out the frequency error in the incoming signal.
An on-chip ADC provides readback of an integrated temperature sensor, an external analog input, the battery voltage, or the RSSI signal, which provides savings on an ADC in some applications. The temperature sensor is accurate to ±10°C over the full operating temperature range of −40°C to +85°C. This accuracy can be improved by doing a 1-point calibration at room temperature and storing the result in memory.
APPLICATIONS
- Low cost wireless data transfer
- Remote control/security systems
- Wireless metering
- Keyless entry
- Home automation
- Process and building control
- Wireless voice
