ROHM BA7755AF, BA7755A Datasheet
1
Video ICs
High-voltage audio head selection
switch
BA7755A / BA7755AF
The standard audio circuits of video cassette recorders and the recording circuits of tape decks use AC bias recording to record the audio signal onto the tape. This bias voltage is some tens of volts, and a high-capacity bias-side
switch is required to electronically switch the head when in playback or record mode.
The BA7755A and BA7755AF are high-voltage switching ICs designed to switch voltages as high as ± 65V
DC or
AC120V
P-P (f = 70Hz).
Two control systems, one for current control, and one for voltage control are provided, so the ICs can be used in circuits that employ either method.
By combining the BA7755A or BA7755AF with the BA7751ALS recording / playback amplifier, it is possible to construct a compact recording / playback audio circuit. In addition, the BA7755A and BA7755AF are an excellent choice
for a wide variety of other high-voltage switching applications.
•
Applications
Video cassette recorders and tape decks
•
Features
1) High withstanding voltage ( ± 65V
DC (Min.),
AC120V
P-P (Min.), f = 70Hz).
2) Circuits for either current control or voltage control
are provided on the chip.
3) Compact SIP 5pin or SOP 8pin package.
•
Block diagram
BA7755AF
12345
SW GND CTRL2 CTRL1
BA7755A
VCC
8765
1234
N.C. N.C. N.C.
HEAD
SWITCH
GND CTRL2
CTRL1
VCC
2
Video ICs BA7755A / BA7755AF
•
Absolute maximum ratings (Ta = 25°C)
Parameter Symbol Limits Unit
V
CC
15 V
Pd 400
∗
1
mW
Topr – 10 ~ + 65
°C
Tstg – 55 ~ + 125 °C
BV
CC2
± 65 V
∗
Reduced by 4mW for each increase in Ta of 1°C over 25°C.
Power supply voltage
Power dissipation
Operating temperature
Storage temperature
Breakdown voltage of switch (pin 2)
•
Recommended operating conditions (Ta = 25°C)
Parameter Unit
V
Max.
139
Typ.Min.
4
Symbol
V
CC
Operating voltage
•
Electrical characteristics (unless otherwise noted, Ta = 25°C and VCC = 9V)
Parameter
Symbol Min. Typ. Max. Unit
Conditions
I
CC1
—
010µA
Pin4 “L” or “OPEN”
Pin5 “OPEN”
I
CC2
2.4 3.9 5.6 mA
Pin 4 “L” or “OPEN”
Pin 5 control current: 200
µA
R
ON
—
8.0 15.0
Ω
Pin 4 “L” or “OPEN”
Pin 5 control current: 200µA
I
LOFF
—
010µA
Pin 4 “H”, or “OPEN”, or “L
”
Pin 5 “OPEN”, pin 2 applied voltage ± 65V
BV
AC
120 160
—
V
P-P
f = 70kHz
V
OS
—
4.3 15.0 mV
Pin 4 “L” or “OPEN”
Pin 5 control current: 200
µA
I
CTRL1 (ON)
50
——
µ
A
—
I
CTRL1 (OFF)
——
1
µ
A
—
V
TH1
1.70 2.15 2.60 V
—
R
CTRL2
21.0 31.0 42.0 k
Ω
—
Supply current
Supply current
Switch-on resistance
Switch leakage current
Switch AC breakdown voltage
Switch offset voltage
CTRL1 SW ON control current
CTRL1 SW OFF control current
CTRL2 threshold voltage
CTRL2 input resistance
Loading...