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Important Notices

Toshiba's TV IC malfunctions under certain conditions

> 18 Jun, 2007

Dear Customers,

We'd like to inform you that our sync detection ICs listed below were found to experience some errors in detection results and unstableness in the VD pulse outputs under certain conditions. Please consider the following instructions when designing a new chassis.

Product type numbers affected
  • TB1305FG, TB1305AFG
    Sync recognition, sync separation, component video SW (2-in / 1-out)
  • TB1308FG
    Sync recognition, sync separation, component video SW (3-in / 1-out)

These ICs determine the input format by counting sync pulses in a period.

When the ICs are configured to operate according to the description in "Manual sync processing mode (A-SYNC = OFF)" on page 13 of the datasheet, that is, in A-SYNC=OFF and HV FREQ=625p mode, the ICs may provide incorrect I2C-bus read data for “V-FORMAT” and “V-FREQ-DET” and generate unstable VD-OUT pulses for the 525i and 625i inputs.

Therefore, your system may malfunction, depending on your usage of the IC.

Toshiba's requests

The A-SYNC=ON setting is required to avoid the above errors, if 525i and 625i signals are also distinguished by the ICs.

However, we have recommended that 525i and 625i signals be detected and synchronized with another device such as a color decoder instead of one of these ICs, because they include non-standard signals. So, we believe that no system being manufactured will cause any errors related to this problem.

When you design a new chassis using one of these ICs, please consider a workaround to avoid an error.

* We will also put the same instructions on each IC datasheet.

We'd appreciate your understanding.


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