MP8830
34
33
26
25
19
18
AFORC
ASENS
BFORC
BSENS
CFORC
CSENS
Forcing voltage for biasing the internal DACs. This is the gate of the N-Channel biasing tran-
sistor for the A channel.
Sensing voltage for biasing the internal DACs. This is the source of the N-channel biasing
transistor and the top terminal of the internal biasing resistor for the A channel.
Forcing voltage for biasing the internal DACs. This is the gate of the N-Channel biasing tran-
sistor for the B channel.
Sensing voltage for biasing the internal DACs. This is the source of the N-Channel biasing
transistor and the top terminal of the internal biasing resistor for the B channel.
Forcing voltage for biasing the internal DACs. This is the gate of the N-Channel biasing tran-
sistor for the C channel.
Sensing voltage for biasing the internal DACs. This is the source of the N-Channel biasing
transistor and the top terminal of the internal biasing resistor for the C channel.
54-63
2-16
AD9-AD0
ADC data output pins. AD9 is the MSB.
CD14-CD0
DAC input pins. CD14-CD6 are the Gain DAC MSB to LSB. CD5-CD0 are the offset DAC
MSB to LSB.
42
40
N/C
No connection.
Digital Ground.
DGND
Note: All digital signals are active high unless otherwise noted.
APPLICATION NOTES FOR CCD SYSTEMS
A typical CCD digitizing configuration is shown in Figure 9.,
which incorporates global gain and offset adjustment as well as
pixel-to-pixel variation correction. The MP8830 can greatly sim-
plify this type of system by replacing the ADCs, the pixel correc-
tion DACs, and the global offset DACs as shown in Figure 10.
One main advantage of the MP8830 is the way the offset and
span for each pixel are controlled. In the traditional application,
the offset and span settings interact requiring addtional com-
putationsforeachpixeladjustment. WiththeMP8830, theoffset
and span settings can be calibrated separately simplifying the
computations necessary.
CCD Buffer
/
Level Shift
Instrumentation Amp Pixel Correction
/
DACs
CCD + 12 V
Black Level Set (Offset)
CCD Global
Gain Set
C
C
D
Wide Bandwidth
Op Amp
DAC
MDAC
D
E
V
I
C
E
V
V
RT
Global
Gain
Pixel Full Scale
A
IN
ADC
RB
DAC
MDAC
MP7529 & Amps
Pixel Zero
MP8780
MP8784
Global
Offset
MP7529
& Amps
1/2
MP7529
with amp
Figure 9. Common Configuration for CCD Digitizer
1 Channel Shown
Rev. 1.00
14
EXAR [ EXAR CORPORATION ]
