At the heart of the Magic Trackpad's logic board lies a Broadcom BCM2042 for Bluetooth connectivity.

We found a Broadcom BCM5974 touch screen controller chip that provides Multi-touch functionality.

Also, an SST 25WF020 provides 2 Mbit of serial flash memory.

This appears to be a TI CD3238, which has been identified by Hearst as a RS232 line driver/receiver. It was also in the original iPhone with a BCM5973A.

The back of the logic board features nothing but blackness and glue.