lm9822ccwmx National Semiconductor Corporation, lm9822ccwmx Datasheet - Page 15

• Manufacturer Part Number: lm9822ccwmx
• Description: Lm9822 3 Channel 42-bit Color Scanner Analog Front End
• Manufacturer: National Semiconductor Corporation

Power-Up Default Register Settings are shown in Bold Italics
Table 2: Configuration Register Parameters
Boost Gain Enable
PGA Gain Value
Offset Polarity
Typical Offset
Offset Value
Parameter
(Address)
Values
Gain
(SIGN
B4(M
B4(M
SB)
• • •
• • •
SB)
B5
B5
B5
0
1
0
0
0
0
0
1
1
1
1
1
0
1
)
Red, Green and Blue Offset DAC Settings (1, 2 & 3)
(MSB)
• • •
• • •
B3
B4
B3
Red, Green and Blue Gain Settings (4, 5 & 6)
0
0
0
1
1
0
0
0
1
1
• • •
• • •
B2
B3
B2
0
0
0
1
1
0
0
0
1
1
Control Bits
• • •
• • •
B1
B2
B1
0
0
0
1
1
0
0
0
1
1
Gain = Boost Gain * PGA Gain
15
B0(LSB)
B0(LSB)
• • •
• • •
B1
0
0
1
1
1
0
0
1
1
1
Boost Gain = 1V/V
Boost Gain = 3V/V
Negative Offset
Positive Offset
(Continued)
Typical Offset = 20LSBs * Offset Value * PGA Gain
PGA Gain (V/V) =.933 + 0.0667 * (PGA Gain Value)
(LSB)
• • •
• • •
B0
0
1
0
0
1
0
1
0
0
1
Typical Offset (with PGA Gain = 1)
12 bit LSBs
Result
+600
+620
0.00
-600
-620
+20
+40
• • •
• • •
-20
-40
0
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