AN8387S Datasheet, PDF (5/6 Pages) Panasonic Semiconductor – 2-channel Linear Driver

ICs for CD/CD-ROM Player
s Pin Descriptions (Cont.)
Pin No. Symbol I/O DC Voltage
13 D2+
O
(2.7V)
14 D2–
O
(0.3V)
17 D1–
O
(0.3V)
18 D1+
O
(2.7V)
Equivalent Circuit
PVCC
AN8387S
Description
Non-inverting output pin
for the channel-2 driver
Inverting output pin for the
channel-2 driver
13 14
or
or
18 17
PGND
Inverting output pin for the
channel-1 driver
Non-inverting output pin
for the channel-1 driver
s Supplementary Explanation
• Operational Description
The AN8387S incorporates the two channels of drivers. Since both channels have the identical functions, the following
describes the channel-1 driver.
• Block Diagram (Channel 1 driver)
Error Amp.
IA
Current
–
Absolute
+
Value
Circuit
IA
Direction
Decision
IA _A
PVCC
19
VLIM
20
Q1
Q2
SW.A
SW.B
SW.C
Vref
S.W
+
R1
57.6
SW.A
–
SW.B
kΩ
R2
57.6
SW. C
kΩ
1kΩ
Thermal
Shutdown
PC
IA=0
SW.B
SW.C
Q3
Q4
24
3
RIN
1
Vref (= ₂ VCC)
17
18
–
+
(RL=8.2Ω)
An error signal (VIN) input to the pin2 is converted into the absolute value input current IA through the error amplifier and
current absolute value circuit. The value of IA is as follows.