Design of High Resolution Read-out IC System for Transparent Fingerprint Sensor

Abstract

This thesis presents a ROIC with Multi Channel Selective Merge (MCSM) method, a kind of noise averaging, a receiver (RX) to improve SNR (Signal to Noise Ratio), area efficiency and overcome a thick cover glass of the display panel. This paper analyzes conventional technology of Touch / Fingerprint recognition ROIC and shows its technical problems. A proposed ROIC system with MCSM is consisted of 16 Transmitter (TX) channels, 42 receiver (RX) channels, and a Transparent Fingerprint Sensor (TFPS). MCSM method increase SNR through post processing with MCU. And several sensing electrodes share one ROIC channel. So it has area efficiency compared with non-MCSM case. The simulated results show that the MCSM increases greater SNR than conventional ROICs. The simulated data shows that the proposed MCSM method achieves 20 dB SNR with area efficiency per RX channel. The fabricated ICs are respectively made of 0.18 um BCD process with 1.7 mm2 and 5.0 mm2 areas.