This thesis describes low-power application-specific integrated circuit (ASIC) designs to mitigate the constraint of cable count in miniature 3-D TEE probes. Receive cable count reduction techniques including subarray beamforming and digital time-division multiplexing (TDM) have been explored and the effectiveness of these techniques has been demonstrated by experimental prototypes. Digital TDM is a reliable technique to reduce cable count but it requires an in-probe datalink for high-speed data communication. A quantitative study on the impact of the datalink performance on B-mode ultrasound image quality has been introduced in this thesis for data communications in future digitized ultrasound probes. Finally, a high-voltage transmitter prototype has been presented for effective cable count reduction in transmission while achieving good power efficiency.