IMX178 Power Lines

There are three power lines on IMX178, they are called:

  • Analog 2.9V Supply (AVDD)
  • Digital 1.2V Supply (DVDD)
  • Interface 1.8V Supply (OVDD)

Foturnately, there are existing power regulator chips on the sensor board to generate the 3 supplies from the main 3.3V supply from the Microcontroller board, as illustrated below:

Sensor Analog PowerSensor Digital PowerSensor Interface Power

Accroding to the documentation page 96~97, there is a specific Power-on/off Sequence to be followed. (DVDD first, OVDD second, AVDD last, followed by XCLR cancellation and then INCK)

There are futrher instructions to be followed, such as things related to I2C.

The power-on timing is already taken cared of by the RC circuits built into the Sensor Board. However, the power-off timing may or may not be taken care of from observation. nevettheless, it may not matter for normal operations.

 

 

NOTE: The mysterious DVDD_SENSOR line seems redundant. I cannot confirm the use of it. But according to “Hi3516AREFB VER.D” reference design, it is used to channel back the 1.8V to DVDD3318_SENSOR pin at Hi3516 chip, hence not relevant to our design.

We can confirm this by multi-metering the pin see if it has a hot 1.8V running through.

result: ___________

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s