Datasheet-1
Table Of Contents
- 1/3-Inch Wide-VGA CMOS Digital Image Sensor
- Features
- Applications
- Ordering Information
- Table of Contents
- List of Figures
- List of Tables
- General Description
- Ball Descriptions
- Pixel Data Format
- Color Device Limitations
- Output Data Format
- Serial Bus Description
- Two-Wire Serial Interface Sample Read and Write Sequences
- Feature Description
- Operational Modes
- Signal Path
- On-Chip Biases
- Window Control
- Blanking Control
- Pixel Integration Control
- Variable ADC Resolution
- Gain Settings
- Black Level Calibration
- Row-wise Noise Correction
- Automatic Gain Control and Automatic Exposure Control
- Pixel Clock Speed
- Hard Reset of Logic
- Soft Reset of Logic
- STANDBY Control
- Monitor Mode Control
- Read Mode Options
- LINE_VALID
- LVDS Serial (Stand-Alone/Stereo) Output
- LVDS Output Format
- Electrical Specifications
- Package Dimensions
- Appendix A – Serial Configurations
- Appendix B – Power-On Reset and Standby Timing
- Revision History
PDF: 3295348826/Source:7478516499 Aptina reserves the right to change products or specifications without notice.
MT9V022_DS - Rev.H 6/10 EN
32 ©2005 Aptina Imaging Corporation. All rights reserved.
MT9V022: 1/3-Inch Wide-VGA Digital Image Sensor
Feature Description
Automatic Gain Control and Automatic Exposure Control
The integrated AEC/AGC unit is responsible for ensuring that optimal auto settings of
exposure and (analog) gain are computed and updated every frame.
AEC and AGC can be individually enabled or disabled by R0xAF. When AEC is disabled
(R0xAF[0] = 0), the sensor uses the manual exposure value in R0x0B. When AGC is
disabled (R0xAF[1] = 0), the sensor uses the manual gain value in R0x35. See Aptina
Technical Note TN-09-17, “MT9V022 AEC and AGC Functions,” for further details.
Figure 27: Controllable and Observable AEC/AGC Registers
The exposure is measured in row-time by reading R0xBB. The exposure range is
1 to 2047. The gain is measured in gain-units by reading R0xBA. The gain range is
16 to 63 (unity gain = 16 gain-units; multiply by 1/16 to get the true gain).
When AEC is enabled (R0xAF[0] = 1), the maximum auto exposure value is limited by
R0xBD; minimum auto exposure is fixed at 1 row.
When AGC is enabled (R0xAF[1] = 1), the maximum auto gain value is limited by R0x36;
minimum auto gain is fixed to 16 gain-units.
The exposure control measures current scene luminosity and desired output luminosity
by accumulating a histogram of pixel values while reading out a frame. The desired
exposure and gain are then calculated from this for subsequent frame.
Pixel Clock Speed
The pixel clock speed is same as the master clock (SYSCLK) at 26.66 MHz by default.
However, when column binning 2 or 4 (R0x0D, bit 2 or 3) is enabled, the pixel clock
speed is reduced by half and one-fourth of the master clock speed respectively. See
“Read Mode Options” on page 34 and “Column Binning” on page 35 for additional infor-
mation.
EXP. LPF
(R0xA8)
1
0
1
0
EXP. SKIP
(R0xA6)
MANUAL EXP.
(R0x0B)
AEC ENABLE
(R0xAF[0])
MAX. EXPOSURE
(R0xBD)
MIN EXP.
AEC
UNIT
To exposure
timing control
AEC
OUTPUT
R0xBB
R0xBA
To analog
gain control
HISTOGRAM
GENERATOR
UNIT
AGC
UNIT
GAIN LPF
(R0xAB)
GAIN SKIP
(R0xA9)
MANUAL GAIN
(R0x35)
AGC ENABLE
(R0xAF[1])
AGC OUTPUT
MAX. GAIN
(R0x36)
MIN GAIN
DESIRED BIN
(desired luminance)
(R0xA5)
CURRENT BIN
(current luminance)
(R0xBC)
1
16