DESCRIPTION OF THE CCD VIDEO BOARDs

The Video board contains the DACS to generate the CCD bias voltages such as OD, RD, OG etc.. The table below shows the range of each bias DAC channel, its address and its output impedance. The DAC value controlling each channel can vary from &000 to &FFF. Because of the different ranges of the channels, writing the same byte to DAC on different channels can have different effects. As an example let us assume that the Video board in use is board 0 (set by links on the board). If we were to send &FFF (i.e DAC full range) to the DAC controlling Pin 2, we would have to write the byte &0D4FFF, pin 2 would then output 30V. If we were to send &FFF to the DAC controlling pin 8, we would have to write the byte &0ECFFF, pin8 in this case would output 20V.

SDSU Video Board Connector

 

 

 

 

 

 

 

output

impedance

Voltage

Range

 

 

 

Pin number on 25 Way connector

Type

address

 

 

1

BIAS

xD0xxx

100R

7.5-30

2

BIAS

xD4xxx

100R

7.5-30

3

BIAS

xD8xxx

1K

5-20

4

BIAS

xDCxxx

1K

5-20

5

BIAS

xE0xxx

1K

5-20

6

BIAS

xE4xxx

1K

5-20

7

BIAS

xE8xxx

1K

5-20

8

BIAS

xECxxx

1K

5-20

9

BIAS

xF0xxx

1K

+/- 5

10

BIAS

xF4xxx

1K

+/- 5

11

BIAS

xF8xxx

1K

+/-10

12

BIAS

xFCxxx

1K

+/-10

22

GND

 

 

 

 

 

 

 

 


Last Updated on 4/20/01
By smtport