ADF7025

The ADF7025 is a low power, highly integrated FSK/GFSK transceiver. It is designed for operation in the licensefree ISM bands of 433MHz and 868MHz in Europe and 915MHz in North America. The ADF7025 is intended for applications operating under the European ETSI EN300-220 or the North American FCC (Part 15) regulatory standards. The ADF7025 is intended for wideband, high data rate applications with deviation frequencies from 150 kHz to 500 kHz and data rates from 9.6kbps to 384kbps. A complete transceiver can be built using a small number of external discrete components, making the ADF7025 very suitable for price-sensitive and area-sensitive applications.

The transmit section contains a VCO and low noise fractional-N PLL with output resolution of <1 ppm. 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, channel spacing, 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 zero-IF architecture is used in the receiver, minimizing power consumption and the external component count and avoiding the need for image rejection. The baseband filter has programmable bandwidths of ±300 kHz, ±450 kHz and ±600 kHz. A high pass pole at 80 kHz eliminates the problem of DC offsets that is characteristic of zero-IF architectures.

The ADF7025 supports a wide variety of programmable features including Rx linearity, sensitivity, and filter bandwidth, allowing the user to trade off receiver sensitivity and selectivity against current consumption, depending on the application.

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 ±5°C over the full operating temperature range of −40°C to +8°C.