LA4445.PDF

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LA4445
Ordering number:ENN1277E
Monolithic Linear IC
LA4445
5.5W 2-Channel AF Power Amplifier
2 (typ.)
• Minimun number of external parts required.
• Small pop noise at the time of power supply ON/OFF and
good starting balance.
• Good ripple rejection : 46dB (typ.)
• Good channel separation.
• Small residual noise (Rg=0).
• Built-in protectors.
a. Thermal protector
b. Overvoltage, surge protector
c. Adjacent pins (9-10, 9-8) short protector
´
Package Dimensions
unit:mm
3049A-SIP12H
[LA4445]
27.0
20.0
4.0
1
12
2.5
2.0
0.5
1.0
0.4
2.0
Specifications
Absolute Maximum Ratings at Ta = 25˚C
SANYO : SIP12H
P
S
C
R
U
V C
m
Q
(
2
V
M
s
v
V C
m
O
1
V
S
s
v
V C
(
t £
0
5
V
M
o
c
I O
p
1
c
3
A
A
p
d
P
m
S
P
m
–
T
c
1
W
O
t
T
–
t
+
˚C
˚C
S
t
T
–
t
+
Operating Conditions at Ta = 25˚C
P
S
C
R
U
R
s
v
V C
1
V
R
l
r
R L
2
c
4
W
O
v
r
V C o
1
1
V
Any and all SANYO products described or contained herein do not have specifications that can handle
applications that require extremely high levels of reliability, such as life-support systems, aircraft’s
control systems, or other applications whose failure can be reasonably expected to result in serious
physical and/or material damage. Consult with your SANYO representative nearest you before using
any SANYO products described or contained herein in such applications.
SANYO assumes no responsibility for equipment failures that result from using products at values that
exceed, even momentarily, rated values (such as maximum ratings, operating condition ranges,or other
parameters) listed in products specifications of any and all SANYO products described or contained
herein.
SANYO Electric Co.,Ltd. Semiconductor Company
TOKYO OFFICE Tokyo Bldg., 1-10, 1 Chome, Ueno, Taito-ku, TOKYO, 110-8534 JAPAN
21500TH (KT)/90196RM/N283KI, TS No.1277–1/7
Features
• Dual channels.
Output : 5.5W
t
11028126.004.png 11028126.005.png 11028126.006.png
LA4445
Operating Characteristics at Ta = 25˚C, V CC =13.2V, R L =4
W
, f=1kHz, Rg=600
W
, with 100
´
100
´
1.5mm 3
Al heat sink, See specified Test Circuit.
R
P
S
C
U
m
t
m
Q
c
I c
7
1
m
V
g
V G
4
5
5
d
O
p
P O
T
2
c
5
5
W
T
h
d
T
P O =
0
1
%
I
r
r i
3
k
W
O
n
v
V N
R
0
1
m
R
W
1
2
m
R
r
R r
R
V
=
f
R
=
4
d
C
s
C
s
R
W
, O
V
=
4
5
d
Equivalent Circuit Block Diagram
Sample Application Circuit
No.1277–2/7
R
11028126.007.png
LA4445
Sample Printed Circuit Pattern
Proper Cares in Mounging Radiator Fin
1. The mounting torque is in the range of 39 to 59N · cm.
2. The distance between screw holes of the radiator fin must coincide with the distance between screw holes of the IC.
With case outline dimensions L and R referred to, the screws must be tightened with the distance between them as
close to each other as possible.
3. The screw to be used must have a head equivalent to the one of truss machine screw or binder machine screw defined
by JIS. Washers must be also used to protect the IC case.
4. No foreign matter such as cutting particles shall exist between heat sink and radiator fin. When applying grease on the
junction surface, it must be applied uniformly on the whole surface.
5. IC lead pins are soldered to the printed circuit board after the radiator fin is mounted on the IC.
No.1277–3/7
11028126.001.png
LA4445
Description of External Parts
C1 (C2) :
Feedback capacitor
Low cutoff frequency f L depends on this feedback capacitor. Increasing the capacitor value makes the
starting time later
C3 (C4) :
Bootstrap capacitor
If the capacitor value is decreased, the output at low frequencies goes lower.
(Recommended value : 47
F min.)
C5 (C6) :
Oscillation blocking capacitor
Polyester film capacitor, being excellent in temperature characteristic, frequency characteristic, is
recommended. The capacitor value can be reduced to 0.047
F depending on the stability of the board.
C7 (C8) :
Output capacitor
The low cutoff frequency depends on this output capacitor. In bridge connection applications the output
capacitor must be normally connected.
C9 :
Decoupling capacitor
Used for the ripple filter. Since the rejection effect is saturated at a certain capacitor value, it is mean-
ingless to increase the capacitor value more than needed. This capacitor, being also used for the time
constant of the pop noise preventer, affects the starting time. Too small a capacitor value makes the pop
noise level higher.
C10 :
Power source capacitor.
R1 (R2) :
Oscillation blocking filter resistor.
W
The usable lower limit of VG is 36dB or thereabouts. When setting VG, oscillation and high cutoff frequency f H
must be considered.
2. External audio muting method
W
, R NF =50
Proper Cares in Using IC
· If the IC is used in the vicinity of the maximum rating, even a slight variation in conditions may cause the maximum
rating to be exceeded, thereby leading to breakdown. Allow an ample margin of variation for supply voltage, etc. and
use the IC in the range where the maximum ratings is not exceeded.
· Printed circuit board
When making the board, refer to the sample printed circuit pattern. No feedback loop must be formed between input and
output. Both Pins GND and Power GND must be shorted at the root of IC pin so that the common impedance can be
reduced.
· Others
The radiator fin on the package must be normally connected to GND.
Some plug jacks to be used for connecting to the external speaker are such that both poles are shorted once when
connecting. In this case, the load is shorted, which may break down the IC.
No.1277–4/7
m
m
IC Application
1. V.G. can be reduced by connecting R NF ’ to the N.F. pin (pins 1, 6)
V.G. is calculated by the following formula.
VG=20log R f / (R NF +R NF ’)
where R f =20k
11028126.002.png
LA4445
No.1277–5/7
11028126.003.png

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