Click here for the enhanced PDF version of this article

To strengthen its portfolio of sub-GHz RF transceivers for high-range, low-power, and low-cost wireless connectivity applications, Analog Devices has released a new narrowband transceiver IC ADF7021. Designed for operation in multiple frequency bands between 80 MHz to 650 MHz and 862 MHz to 940 MHz, it offers best-in class receiver sensitivity of -123 dBm at 1 kbps (868/915 MHz). It also implements on-chip Tx/Rx switch, voltage-controlled oscillator (VCO) tank and RF/IF filters, fully automatic frequency control (AFC) and 7-bit analog-to-digital converter (ADC).

It is fully compliant with European ETSI-300-220, North American FCC Part 15 and Part 90, 95 and Japan ARIB STD-T67 regulatory standards. Because of its high receiver sensitivity, superior interference blocking of 60 dB at 1 MHz, and +6 dBm IP3, the ADF7021 is suited for high reliability and maximum-range applications such as wireless automatic meter reading (AMR), wireless home automation, industrial control and automation and remote security.

A highly integrated 2FSK/3FSK/4FSK transceiver, the 0.25 µm-based CMOS transceiver offers both Gaussian and raised cosine data filtering options to improve spectral efficiency for narrowband applications. The transmit section contains a VCO and a low-noise fractional-N PLL with output resolution of <1 ppm. This frequency-agile PLL allows the ADF7021 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 63 steps from 16 dBm to +13 dBm and has an automatic power ramp control to prevent spectral splatter and help meet regulatory standards. The transceiver RF frequency, channel spacing, and modulation are programmable using a simple three-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 (100 kHz), minimizing power consumption and the external component count while avoiding interference problems at low frequencies. The IF filter has programmable bandwidths of 12.5 kHz, 18.75 kHz and 25 kHz. Furthermore, the ADF7021 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 with programmable pull-in range, allowing the PLL to track out the frequency error in the incoming signal. An on-chip 7-bit ADC provides read back of an integrated temperature sensor, an external analog input, the battery voltage, and the RSSI signal, which can result in cost savings, according to ADI.

Additionally, to help speed wireless product development, ADI is offering its ADIismLINK development tool. Using the ADIismLINK tool, wireless product designers can transfer data between multiple units (slave node) and a master node (another ADF702x device) without having to spend time developing their own protocol software.

The ADF7021 is sampling with production slated for November. It comes in a 48-lead CSP package and is priced at $2.85 per unit in quantities of 1,000.
Analog Devices Inc.
(781) 937-1428
www.analog.com

RSS    Save to Del.icio.us  Digg This