A 7-band CCD-in-CMOS multispectral TDI imager
Host Publication: International Image Sensor Workshop 2017
Authors: D. San Segundo Bello, M. De Bock, P. Boulenc, R. Vandebriel, L. Wu, J. Van Olmen, V. Malandruccolo, J. Craninckx, L. Haspeslagh, S. Guerrieri, M. Rosmeulen and J. Borremans
Publication Date: Aug. 2017
We have developed a TDI sensor with 7 bands of 256 rows each using imec's CCD-in-CMOS technology. Each band uses individual on-chip sequencers and CCD drivers for the 5.4 µm four-phase TDI pixels. Line-by-line row selection per band, individual band selection and bi-directionality enable multispectral TDI. CCD bands operate continuously and time interleaved, and top or bottom outputs can be connected to shared column-parallel delta-sigma ADCs through a column line. ADC outputs are
serialized to 32 1.2V LVDS outputs along with two clock signals. These outputs are capable of running at an aggregate of >50Gb/s using on-chip PLLs.
The sensor has been packaged in a ceramic PGA package. As a proof-of-concept, an RGB butcher-brick filter has been applied to the glass lid of the sensor to enable multicolor TDI. The sensor has also been integrated into a custom CoaXPress camera.
The TDI sensor chip consumes 2.5W at full speed. Two pixel variations have been used. A high gain pixel achieves 10 electrons rms read noise and a full well of 12800 electrons rms with a conversion gain of 62 µV/e. A low gain pixel achieves 40 electrons rms read noise and a full well of 31600 electrons rms with a conversion gain of 28 µV/e.