TRF7900APWG4 [Texas Instruments]

The TRF7900A is a dual integrated RF transceiver designed for Human Interface Devices (HID). Operating at 27 MHz, it integrates multiple components (PLL, RF mixer, simulated SAW filter, tuning circuit, and miscellaneous passive components) to provide frequency selection from 8 discrete channels. This integration lowers component, manufacturing and system costs. The TRF7900A simplifies system design by reducing system component count and manual circuit tuning. By integrating the PLL, SAW filter, and RF mixer, the TRF7900A eliminates the manual tuning of RLC circuits required in traditional implementations. The optimized receiver design enables simultaneous reception on both parallel channels up to 5 kHz (10 kbps Miller encoding) per channel. A receive strength signal indicator register can be read via the I2C bus to determine if the transmit signal is too weak (weak battery or too far), or if there is too much noise on the selected channel in the user's area.