IBIS4-6600_09 Datasheet, PDF (10/35 Pages) Cypress Semiconductor – 6.6 MP CMOS Image Sensor

IBIS4-6600 CYII4SM6600AB
Stage 1: Offset, FPN Correction, and Multiplexing
In the first stage, the signals from the buses are subtracted and
the offset from the DACs is added. After a system reset, the
analog multiplexer is configured for two outputs (see the bit
settings in the AMPLIFIER Register on page 22). In case
ONE_OUT is set to 1, the two signals S1 and S2 are multiplexed
to one output (output 1). The amplifiers of Stage 2 and Stage 3
of the second output path are then put in standby. The speed and
power consumption of the first stage can be controlled through
the resistor connected to CMD_OUT_1.
Stage 2: Programmable Gain Amplifier
The second stage provides the gain, which is adjustable
between 1.36 and 17.38 in steps of approximately 20.25 (~1.2).
An overview of the gain settings is given in Table 4. The speed
and power consumption of the second stage can be controlled
through the resistor connected to CMD_OUT_2.
Table 4. PGA Gain Settings
Bits
0000
0001
0010
0011
0100
DC Gain
1.36
1.64
1.95
2.35
2.82
0101
3.32
0110
3.93
0111
4.63
Bits
1000
1001
1010
1011
1100
1101
1110
1111
DC Gain
5.40
6.35
7.44
8.79
10.31
12.36
14.67
17.38
Stage 3: Output Drivers
The speed and power consumption of the third stage can be
controlled through the resistor connected to CMD_OUT_3. The
output drivers are designed to drive a 20 pF output load at
40 Msamples/s with a bias resistor of 100 kΩ.
Offset DACs
Figure 11 shows how the DAC registers influence the black
reference voltages of the two different channels. The offset is
mainly given through DAC_raw. DAC_fine can be used to shift
the reference voltage of bus 2 up or down to compensate for
different offsets in the two channels.
Figure 11. Offset for the Two Channels through DAC_RAW and DAC_FINE
DAC_RAW_REG<0:7
DAC_raw
out
10K
200K
blackref
bus1
RCAL
+ _VCAL
rcal
pad RCAL_DAC_OUT
VDDA
50K
10K
blackref
bus2
DAC_FINE_REG<0:7
DAC_fine
out
50K
rcal
floating
GNDA
200K
Note that in this figure, “K” represents KΩ.
Document Number: 001-02366 Rev. *E
Page 10 of 35
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