The ADF7020-1 is a low power, highly integrated FSK/ GFSK/ ASK/ OOK/ GOOK transceiver designed for operation in thelow UHF and VHF bands. The ADF7020-1 uses an externalVCO inductor that allows users to set the operating frequencyanywhere between 135 MHz and 650 MHz. Using the divide-by-2circuit allows users to operate the device as low as 80 MHz.The typical range of the VCO is about 10% of the operatingfrequency. A complete transceiver can be built using a smallnumber of external discrete components, making the ADF7020-1 very suitable for price-sensitive and area-sensitiveapplications.

The transmit section contains a VCO and low noisefractional-N PLL with output resolution of <1 ppm. Thisfrequency agile PLL allows the ADF7020-1 to be used infrequency-hopping spread spectrum (FHSS) systems. The VCOoperates at twice the fundamental frequency to reduce spuriousemissions and frequency pulling problems.

The transmitter output power is programmable in 63 steps from−20 dBm to +13 dBm. The transceiver RF frequency, channelspacing, and modulation are programmable using a simple 3-wire interface. The device operates with a power supply range of2.3 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 componentcount and avoiding interference problems at low frequencies.The ADF7020-1 supports a wide variety of programmablefeatures, including Rx linearity, sensitivity, and IF bandwidth,allowing the user to trade off receiver sensitivity and selectivityfor current consumption, depending on the application. Thereceiver also features a patent-pending automatic frequencycontrol (AFC) loop, allowing the PLL to compensate forfrequency error in the incoming signal.

An on-chip ADC provides readback of an integrated temperaturesensor, an external analog input, the battery voltage, or theRSSI signal, which provides savings on an ADC in someapplications. The temperature sensor is accurate to ±10°C overthe full operating temperature range of −40°C to +85°C. Thisaccuracy can be improved by doing a 1-point calibration atroom temperature and storing the result in memory.

Applications

• Low cost wireless data transfer
• Wireless medical applications
• Remote control/security systems
• Wireless metering
• Keyless entry
• Home automation
• Process and building control

At least one model within this product family is in production and available for purchase. The product is appropriate for new designs but newer alternatives may exist.