EV76C560/661 Temporal Row
Noise Reduction
Rev. 0.3 Feb 12 / VP
BRIEF DESCRIPTION
- defines the EV76C560/661 set-up to reduce the temporal noise in Global Shutter
mode
Application Note
APPLICABLE PRODUCT
- EV76C560
- EV76C661
EOS-AN022
KEYWORDS
- Global Shutter
- Temporal Row Noise
1. DESCRIPTION
By default, our EV76C560/661 sensors, in Global Shutter mode, have a non negligible temporal row noise. As this
parameter is hard to correct, even with a powerful image processing, a hardware solution allows reducing this noise.
The noise level will then be equivalent to the row noise in Rolling Shutter mode.
The sensor has an internal power supply dedicated to the pixel. This power supply being noisy and the PSRR (Power
Supply Rejection Ratio) in Global Shutter being poor, the sensor will need an external pixel power supply.
For best results, the external power supply needs to be noise free.
2. PROCEDURE
The pins 4 and 6 on the sensor package are, by default, not connected. To reduce the noise, the user will have to follow
the hardware integration given in the drawing here under (Figure 1) and proceed to a register modification.
The register modification is mandatory in order to avoid any electrical conflict between the internal and the external
power supplies. The register modification is given below:
-
Register 0x41, bits 8 and 9 must be at 1.
-
The default value “0x41 = 0x9630” (see Application Note 014) becomes “0x41 = 0x9730”.
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EV76C560
Pin 4
Resistor
Noise Free
50 ohms
3V
Power Supply
(min 50mA)
Pin 6
Figure 1 : Proximity integration for pixel external power supply using the EV76C560
EV76C661
Pin 4
Resistor
Noise Free
50 ohms
2.8V
Power Supply
(min 50mA)
Pin 6
Figure 2 : Proximity integration for pixel external power supply using the EV76C661
Note
For the EV76C560, the power supply used for the pins 4 and 6 can be 3.3V. The most important is that it must be noise
free. If not, a part of the noise introduced by the power supply will be directly applied on the pixel. Then, there is no
benefit to use an external power supply…
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EOS-AN022
Rev. 0.3 Feb 12 / VP