Technical Note

BH76330FVM, BH76331FVM, BH76360FV, BH76361FV,

BH76332FVM, BH76333FVM, BH76362FV, BH76363FV

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2009.04 - Rev.A

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Cautions for selection and use of application parts

When using this IC by itself ①

Input type

Input impedance

Zin

Capacity of input coupling

capacitor (recommended

value)

Capacity of output coupling

capacitor (recommended

value)

Sync_Tip_Clamp

10 M



0.1 µF

470 µF to 1000 µF

Bias

150 k



4.7 µF

Method for determining capacity of input coupling capacitor

The HPF is comprised of an input coupling capacitor and the internal input impedance Zin of the IC. Since the fc value of this HPF is

determined using the following equation (a), the above recommended capacity for the input capacitor is derived. Usually, the cutoff

frequency fc is several Hz.

fc = 1 / (2π × C × Zin)・・・・(a)

When evaluating the sag characteristics and determining the capacity of the capacitor during video signal input, a horizontal stripe signal

called "H bar" (shown in Fig. 10) is suitable, and this type of signal is used instead of a color bar signal to evaluate characteristics and

determine capacity.

Method for determining capacity of output coupling capacitor

The output pins of models with a 75

 driver [BH76330FVM and BH76331FVM] have an HPF comprised of an output coupling capacitor and

approximately 470 µF to 1000 µF.

As for models without the 75

 driver, an HPF is similarly comprised using the capacity of the output coupling capacitor and the input

impedance of the IC connected at the next stage, and the capacitance required for the output coupling capacitor should be estimated using

equation (a).

When this IC is used as a standalone device ②

In models that include a 75

 driver [BH76330FVM and BH76331FVM], up to two monitors (loads) can be connected (a connection example

is shown in Fig. 12). When there are multiple loads, the number of output coupling capacitors must be increased or a larger capacitance

must be used, based on the table shown below.

Application circuit example

No. of output capacitors

Capacitance per output capacitor (recommended values)

Fig. 12 (a)

No. of drives required

470 µF to 1000 µF (same as with one drive)

Fig. 12 (b)

1

(No. of drive × 470 µF to 1000) uF

When this IC is used as a standalone device ③

The BH76330FVM is the only model that can be used without an output coupling capacitor.

This use method not only enables reductions in board space and part-related costs, but it is able to improve the sag characteristics by

improving low-range frequency response. However, when the output coupling capacitor is omitted, a direct current flows to the connected

set, so the specifications of the connected set should be noted carefully before starting use.

Note also that only one load can be connected when the output coupling capacitor is omitted.

Fig.11 Example of Screen with Obvious Sag (H-bar Signal)

7

OUT

470μF

75Ω

75Ω

470μF

75Ω

75Ω

monitor

monitor

7

OUT

(470×2)μF

75Ω

75Ω

75Ω

75Ω

monitor

monitor

Fig. 12 (a) Application Circuit Example 1 (Two Drives)

Fig. 12 (b) Application Circuit Example 2 (Two Drives)

7

OUT

75Ω

75Ω

monitor

BH76330FV

Fig.13 Application Example without Output Coupling Capacitor

Voltage at output ≒0.16V

02V

When this voltage load resistance is applied,

a direct current is generated.