Applications include document scanning, mark readers, gaming and office automation

equipment.

Functional Description

Each of the three modules in the family, PI227/228/229, consist of four major components.

The first of them is the PCB on which the 27 imaging chips, PI3020, are bonded. These

sensor chips, produced by Peripheral Imaging Corporation, are monolithic devices with 64

photo sensing elements. Each of twenty seven chips are complete self contained

scanning chips and have their control circuits integrated in the chips, so that they can be

cascaded to provide 1728 photo-elements module. The PI3020 chips are integrated with

the photo sensors' associated multiplex switches, a digital shift register and chip selection

switch. The chip's shift register sequentially clocks out the integrated image charges from

each sensing elements and passes them through the chip-select switch and out onto the

video line. The chip-select switches are sequentially switched as each of the predecessor

chip completes its scan. These 27 sensors, bonded on a PCB, are grouped into 4 sub-

cascaded sections. Each contiguously cascaded chips section are connected on

separate video lines, accordingly providing four video outputs VOUT1, VOUT2, VOUT3

and VOUT4. Before the signal charges from the four video lines appear at their

respective outputs they are converted to signal voltages by four on-board buffer

amplifiers, one for each of its corresponding video section. The first three sections

VOUT1, VOUT2, and VOUT3 have 7 sensor chips, while the VOUT4 has 6 sensor chips.

Since each sensor chip have 64 pixels, there are a total of 1728 pixels. See Figure 1.

PI227/228/229 Module Block Diagram.

Figure 1. PI227/228/229 Module Block Diagram

(See Table 1 for pin-out designation)

PAGE 2 OF 10 - PI227/228/229, 01-31-04

CP

SP

GRD

BUFFER

SHIFT REGISTER

VIDEO 1 PIXEL 1 TO 448

VIDEO 2 PIXEL 449 TO 896

VIDEO 3 PIXEL 897 TO 1344

VIDEO 4 PIXEL 1345 TO 1728

AMPL 1

AMPL 2

AMPL 3

AMPL 4

ROD LENSE

GLED

VLED

PHOTO SENSORS

1728

1 2 3

VN(-V)

VDD(+5)

GRD

VOUT1

VOUT2

VOUT3

VOUT4

LED

LED

LED

LED

LED

LED

LED

LED