7

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LM9830 can correct for using its internal PGA.

Note 13:

PGA Gain Error is the maximum difference between the measured gain for any PGA code and the ideal gain calculated by using the formula

where

.

For this reason, it is recommended that the parallel port be driven to 0x00h by the PC when not in the reverse transfer phase. When reading coefficient data from register 6

(register 3 = 00000XX1 binary), the EPP handshaking generated by the host PC may be faster than the data can settle. For this reason it is recommended that software

handshaking (“PS2” mode) be used when verifying coefficient data.

CCD Output Signal

Gain

PGA

V

V

----





G

0

X

PGA code

32

---------------------------

+

=X

G

31

G

0

–

()

32

31

------

=