PixArt Imaging Inc.

PAS005B

CMOS Image Sensor IC

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PixArt Imaging Inc.

Mechanical shutter

opening period

Vsync

Non-Valid

Data

Valid

Data

Array

leakage

Array

reset

start point

Active exposure time

end point

Mechanical

shutter

Exposure start point

programmed by ny, ne

Image exposure and

readout timing

Vsync extension

programmed by LPF

External Sync

Fig. 4.4-2 Snapshot mode two – Exposure time smaller than shutter speed limitation.

4.5 External synchronization control

The sensor core timing can be reset by external “Sync” pin. The internal counter will start from initial point at

the rising edge of trigger signal “Sync”. Meanwhile, Vsync signal is reset to zero. Waiting the coming of

Vsync pulse, a valid frame will be output after the pulse with the programmed ny, ne and gain code, as shown

in Figs. 4.4-1 and 4.4-2.

4.6 Frame rate

Frame rate =

line

t

LPF

_

)

2

1

(

1

⋅

+

+