By Analog Devices Inc 95
ADI’s ADF7020 and ADF7023 are transceivers designed for operation in the license-free ISM bands at 433 MHz, 868 MHz, and 915 MHz. These transceivers are ideal 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. They operate from a 2.3 V to 3.6 V power supply with programmable output power from -16 dBm to +13 dBm in 0.3 dBm steps. The ADF7020 receiver sensitivity is -117.5 dBm at 1 kbits/s in FSK mode or -110.5 dBm at 9.6 kbits/s. Power consumption is 20 mA in receive mode and 30 mA in transmit mode (+10 dBm 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 <1 µA in power down mode.
The ADF7023 transmit RF synthesizer contains a VCO and a low noise fractional-N PLL with an output channel frequency resolution of 400 Hz. The VCO operates at 2× or 4×, the fundamental frequency to reduce spurious emissions. The receive and transmit synthesizer bandwidths are automatically and independently configured to achieve optimum phase noise, modulation quality, and settling time. The transmitter output power is programmable from -20 dBm to +13.5 dBm with automatic PA ramping to meet transient spurious specifications. The part possesses both single-ended and differential PAs, which allows for Tx antenna diversity.
The ADF7020 and ADF7023 are perfect for smart metering, IEEE 802.15.4g, and wireless sensor networks.