condition is not satisfied. Figure 4

details the clock waveform require-

ments and overlap tolerances.

The video amplifier buffers the signal

from the integrator for output from the

imager. Care must be taken to keep the

load on this amplifier within its ability

to drive highly reactive or low imped-

ance loads. The half power bandwidth

into an external load of 10 pF is

150 MHz. It is recommended that the

output video signal be buffered with a

wide bandwidth emitter follower or

other appropriate amplifier to provide

Keep the external amplifier close to

the output pins to minimize stray

inductive and capacitive coupling of

the output signal that can harm

signal quality.

Exposure Control and

Antiblooming

An exposure control feature in the

P-series imagers supports variable

charge accumulation time in the photo-

diode. When the antiblooming gate

voltage (

charge is drained from the pixel

storage gate to the exposure control

drain. During normal charge collection

in the photodiode,

state. Due to the timing requirements

of the exposure control mode, charge

is always accumulated at the end of

the period just before the charge is

transferred to the readout register.

Figure 3 includes the timing require-

ments for exposure control with the

antiblooming gate. The exposure

control timing shown will act on the

charge packets that emerge as video

data on the next readout cycle.

Signal

Function

State

Voltage

Tolerance

ø

Horizontal Clocks

High

5

±5%

Low

0

ø

TG

Transfer Gate

High

8

±10%

Low

0

ø

PG

Photo Gate

High

8

±5%

Low

-4

ø

AB

Antiblooming Gate

High

4

±5%

Low

-4

Output Gate

3

±5%

ø

RG

Reset Gate

High

8

±10%

Low

0

Amplifier Voltage Supply

12

±5%

Amplifier Reset Drain

9.5

±5%

Amplifier Return / Light Shield

0

Table 4. Operating Voltages

Min

Max

Units

Tempera

emperature

ture

Storage

-25

+85

°C

Operating

-25

+55

°C

V olta

oltage

ge (with

(with respect

respect to

to GND)

GND)

Pins 3, 4, 17 - 19

-0.3

+18

V

Pins 2, 10, 20

-0.3

+18

V

Pins 1, 11

-0.3

+ 0

V

Pins 15, 16

-4.3

+18

V

Linear Photodiode Array

Imagers

www.perkinelmer.com/opto

Imager Performance

In P-series images each element per-

forms its own function admirably

while integrating smoothly with the

other elements on the team. The pho-

todiodes efficiently transform light

to charge, the readout registers accu-

rately transport the charge to the

amplifier, and the amplifier delivers

Output Amplifier (cont.)

a clean, robust signal for use in

image processing electronics. While

the actual performance of these

imagers depends strongly on the

details of the electronics and timing

the camera provides, their straight-

forward implementation require-

ments facilitate optimum designs.

Precautionary Note: The CCD output pin (Pin #2) must never be shorted to either V

applied to the device. Catastrophic device failure will result!

DSP-101 01H - 7/2002W Page 5