GENERAL DESCRIPTION

The ADF7021-V is a high performance, low power, narrow-band RF transceiver based on the ADF7021-N. The architecture of the ADF7021-V transceiver is similar to that of the ADF7021-N except that an external VCO is used by the on-chip RF synthesizer for applications that require improved phase noise performance.

The ADF7021-V is designed to operate in both the license-free ISM bands and in the licensed bands from 80 MHz to 960 MHz.

To minimize RF feedthrough and spurious emissions, the external VCO operates at 2× or 4× the desired RF frequency; the ADF7021-V supports a maximum VCO frequency operation of 1920 MHz. The 4× VCO operation is programmable by enabling an additional on-chip divide-by-2 outside the RF synthesizer loop and offers improved phase noise performance.

As with the ADF7021-N receiver, the IF filter bandwidths of 9 kHz, 13.5 kHz, and 18.5 kHz are supported, making the ADF7021-V ideally suited to worldwide narrow-band telemetry applications.

The part has both Gaussian and raised cosine transmit data filtering options to improve spectral efficiency for narrow-band applications. It is suitable for circuit applications targeted at the following:

• European ETSI EN 300 220

• North American FCC Part 15, Part 90, and Part 95

• Japanese ARIB STD-T67

• Korean short-range device regulations

• Chinese short-range device regulations

A complete transceiver can be built using a small number of discrete external components, making the ADF7021-V very suitable for area-sensitive, high performance driven applications

FEATURES

High performance, low power, narrow-band transceiver

Enhanced performance ADF7021-N with external VCO

Frequency bands using external VCO: 80 MHz to 960 MHz

Improved adjacent channel power (ACP) and adjacent channel rejection (ACR) compared with the ADF7021-N

Programmable IF filter bandwidths: 9 kHz, 13.5 kHz, and 18.5 kHz

Modulation schemes: 2FSK, 3FSK, 4FSK, MSK

Spectral shaping: Gaussian and raised cosine filtering

Data rates: 0.05 kbps to 24 kbps

Power supply: 2.3 V to 3.6 V

Programmable output power: −16 dBm to +13 dBm in 63 steps

Automatic power amplifier (PA) ramp control

Receiver sensitivity

−125 dBm at 250 bps, 2FSK

−122 dBm at 1 kbps, 2FSK

Patent pending, on-chip image rejection calibration

On-chip fractional-N PLL

On-chip, 7-bit ADC and temperature sensor

Fully automatic frequency control (AFC) loop

Digital received signal strength indication (RSSI)

Integrated Tx/Rx switch

Leakage current in power-down mode: 0.1 μA

APPLICATIONS

Narrow-band, short-range device (SRD) standards

ETSI EN 300 220

500 mW output power capability in 869 MHz g3 subband with external PA

High performance receiver rejection, blocking, and adjacent channel power (ACP)

FCC Part 90 (meets Emission Mask D requirements)

FCC Part 95

ARIB STD-T67

Wireless metering

Narrow-band wireless telemetry