BA7657F ROHM Electronics, BA7657F Datasheet - Page 11

• Manufacturer Part Number: BA7657F
• Manufacturer: ROHM Electronics

•
(1) Frequency characteristics
Use an oscillator to input a sine wave (V
1MHz / 230MHz) to the color signal pins.
To select R1, G1 and B1: Set the switch to 1.
To select R2, G2 and B2: Set the switch to 2.
(2) Frequency characteristic deviation
Use an oscillator to input a sine wave (V
1MHz / 100MHz) to the color signal pins.
To select R1, G1 and B1: Set the switch to 1.
To select R2, G2 and B2: Set the switch to 2.
(3) Input pin crosstalk (1)
Use an oscillator to input a sine wave (V
10MHz) to IN1.
Use a capacitor to connect IN2 to GND. Set the switch
to 2, then select output IN2 and measure.
(4) Input pin crosstalk 2
Use an oscillator to input a sine wave (V
•
(1) Analog switches
Used for switching between the two sets of RGB color
signals. Connect the high voltage to CTL to select IN1,
or the low voltage to select IN2.
(2) Digital switches
Used for switching between the two sets of HD / VD
synchronization signals. Connect the high voltage to
CTL to select the HD / VD synchronization signal for
IN1, or the low voltage to select the HD / VD synchro-
nization signal for IN2.
(3) Synchronization separator
Used to output the synchronization signal after separat-
ing it from the composite signal (Sync on Green).
When the HD signal is input it activates the synchro-
nization signal detector, stopping the synchronization
separator. The length of time that the synchronization
separator remains stopped is set according to the con-
stant attached to the detector wave pin of the synchro-
nization detector.
Multimedia ICs
Procedure for measurement of frequency characteristics and crosstalk characteristics
Circuit operation
Gf1 = Gv (f = 1MHz) – Gv (230MHz) [dB]
Gf1 = Gv (f = 1MHz) – Gv (100MHz) [dB]
Gf (B1) – Gf (R1) [dB]
CTI1 = 20log (V
Gfl = Gf (IN1) – Gf (IN2) [dB]
GfB = Gf (R1) – Gf (G1), Gf (G1) – Gf (B1),
OUT
/ V
IN
) [dB]
IN
IN
IN
IN
= 1.0V
= 1.0V
= 1.0V
= 1.0V
P-P
P-P
P-P
P-P
, f =
, f =
, f =
, f =
Relationship between inputs and outputs
230MHz) to IN1.
Connect IN2 to the ground through a capacitor.
Set the switch to 2, input to IN2, then measure.
(5) Block crosstalk 1
Use an oscillator to input a sine wave (V
10MHz) to G1 and B1.
Connect R1 to the ground through a capacitor.
Set the switch to 1 and measure the R output.
Similarly,
(6) Block crosstalk 2
Use an oscillator to input a sine wave (V
230MHz) to G1 and B1.
Connect R1 to the ground through a capacitor.
Set the switch to 1 and measure the R output.
Similarly,
HD
—
—
—
CTI2 = 20log (V
CTB1R = 20log (V
CTB1G = 20log (V
CTB1B = 20log (V
CTB2R = 20log (V
CTB2G = 20log (V
CTB2B = 20log (V
VD Sync on Green
—
—
—
Input
—
—
—
OUT
OUT
OUT
OUT
OUT
OUT
OUT
/ V
BA7657F / BA7657S
B / V
B / V
R / V
R / V
G / V
G / V
IN
) [dB]
HD
—
—
—
IN
IN
IN
IN
IN
IN
R1) [dB]
R1) [dB]
G1) [dB]
G1) [dB]
B1) [dB]
B1) [dB]
VD Composite Sync
—
—
—
Output
IN
IN
= 1.0V
= 1.0V
—
—
—
—
—
P-P
P-P
, f =
, f =
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