AN8387S
I
A
= |V
IN
–V
ref
|
R
IN
+1kΩ
1) When V
IN
>V
ref
, the direction determining circuit operates
so that the following conditions are met.
SW.A : +
SW.B : ON
SW.C : OFF
2) When V
IN
<V
ref
, the direction determining circuit operates
so that the following conditions are met.
SW.A : –
SW.B : OFF
SW.C : ON
The output (V
+
–V
–
) between the pins18 and 17 has the
following relation with the input (V
IN
–V
ref
) between the
pins 2 and 4.
57.6kΩ
(V
IN
–V
ref
)
(V
+
–V
–
) =
R
IN
+1kΩ
Therefore, the driver’s gain G will be as follows. (when the
motor load R
L
is 8.2Ω)
G=
(V
+
–V
–
)
(V
IN
–V
ref
)
=
57.6kΩ
1kΩ + R
IN
ICs for CD/CD-ROM Player
–V
–
| is limited within the following range.
2.25V
≤
|V
+
–V
–
|
≤
3V
When the pin20 is short-circuited to GND,
|V
+
–V
–
|
≤
130mV results regardless of an input error signal
(V
IN
).
If the pin20 is prepared to short-circuit to GND at power-on of
the set, it can be used to prevent operation error at power-on
of the motor or actuator.
When the pin20 is not used, short-circuit it to the pins1 and
10.
The pin3 is a PC pin. If a voltage of 2.8V or more is
applied to this pin, SW.B and SW.C are turned on, I
A
becomes
0mA, and the base current flows to the bases of Q3 and Q4
simultaneously to turn on Q3 and Q4. As a result, the
pins17 and 18 are almost short-circuited to P.GND.
This IC incorporates the thermal shutdown circuit. If
the chip temperature of the IC comes to about 160˚C,
both drivers of the two channels are turned off. (the output
pins17, 18, 14, and 13 are short-circuited to P.GND)
Similarly, if the applied voltage (V
ref
) of the V
ref
pin4
comes to 1V or less, both drivers of the two channels are
turned off.
The output voltage V
_
of the pin17 and V
+
of the pin18 can
be limited by applying a voltage to the VLIM pin20.
For example, if a voltage of 3V is applied to the pin20
when V
CC
= 9V and R
L
= 8.2Ω, the maximum value of |V
+
•
Driver Input/Output Characteristics
Input Offset (V
IOF
)
Output Offset (V
OOF
)
Dead Zone (|V
DZ
|)
Transfer Gain (+) (G
+
)
(+), (–) Transfer Gain Ratio (R
G
)
V
CC
= 9V
P.V
CC
= 9V
V
ref
= 4.5V
•
Characteristics Curve
P
D
–Ta
Output
V
1
, V
2
0.25V
B
4
Power Dissipation P
D
(mW)
V
IOF
B
5
G–
2000
1800
1600
1400
1200
1000
800
600
400
200
0
– 0.25V
0
20
40
60
80
100
120
140
Ambient Temperature Ta (˚C)
When Mounted to PCB : Material. Glass Epoxy PCB.
Size…5cm
×
5cm
×
0.8mm
θj–
a=83.3˚C/W
V
OOF
4.43V
4.45V
B3
4.5V
Input
4.55V
4.57V
V
IN
|V
DZ
|
B
2
C
–
B
1
G
+
=
B
5
–B
4
B
2
–B
1
G
G
–
=
R
G
=
+
20mV ,
20mV ,
G
–
PANASONIC [ PANASONIC SEMICONDUCTOR ]
