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STV9211

STV9211 + STV9556/55/53 applications hints

10

STV9211 + STV9556/55/53 APPLICATIONS HINTS

10.1

InfraBlack adjustment procedure (Cut-off)

The STV9211 allows to adjust independantly the InfraBlack levels of the 3 video outputs with a high

resolution. This ajustment is done via the 3 infra-black level registers (IBL1, IBL2 and IBL3). In

order to have the optimum resolution, it is necessary, first, to set the video signal inside the linear

area of the amplifier, by programing the infra-black range register IBR (26 or 36V) and the infra-

black offset register IBO.

Step 1

Setting of the infra-black range register IBR (Register 14, bit 0. See I²C table 6).

This register must be selected, either to 1.3V to get a 26V Cut-off adjustment range with the

STV95xx amplifier or to 1.8V to get a 36V range (see

Step 2

Setting of the Infra-black offset register IBO (Register 14, bit 1, 2 & 3. See I²C table 6).

This register selects the Vib Offset. It allows to keep the video signal inside the linearity area of

the amplifier.

The register value depends on the amplifier high voltage supply (Vdd).

In kit with the STV95xx amplifier family, we recommend the following programming:

Example:

For Vdd=101V +/-5% and Brightness before Drive, IBO must be set to 100.

Table 8: Setting of the infra-black offset register (IBO)

Vdd (±5%)

Case 1:

Brightness before Drive

Case 2:

Brightness after Drive

Binary

Decimal

Binary

Decimal

112 to 115V

001

1

011

3

107 to 111V

010

2

100

4

102 to 106V

011

3

101

5

97 to 101V

100

4

110

6

92 to 96V

101

5

111

7

88 to 91

110

6

111

7

87 and below

111

7

111

7