LA4422.PDF

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LA4422
Ordering number:ENN556F
Monolithic Linear IC
LA4422
5.8W typ AF Power Amplifier for
Car Stereos, Car Radios
Features
• High gain (53dB typ.) and high output (5.8W typ).
• Soft clip.
• Small number of external parts (4 pcs).
• Bridge construction usable (P O =18W/R L =4
Package Dimensions
unit:mm
3018A-SIP10FD
).
• Built-in thermal shutdown circuit against load short, over-
load.
• Built-in circuit to prevent pop noise at the time of power
supply ON.
• SIP package (single ended pins) facilitating easy mount-
ing.
W
[LA4422]
25.5
24.0
3.6
12.0
3.6
1
10
0.45
1.6
1.32
2.54
0.5
1.3
Specifications
Absolute Maximum Ratings at Ta = 25˚C
SANYO : SIP10FD
P
S
C
R
U
M
s
v
V C
m
1
V
M
o
c
I O
P
1
f
p
8
f
P
1
f
*
4
A
S
s
v
V
0
4
V
A
p
d
P
m
7W
O
t
T
–
t
+
˚C
˚C
S
t
T
–
t
+
* : 100´100´1.5mm 3 Al heat sink used.
Operating Conditions at Ta = 25˚C
P
S
C
R
U
R
s
v
V C
1
V
R
l
r
R L
4
W
Operating Characteristics at Ta = 25˚C, V CC =13.2V, R L =4
W
, f=1kHz, 100
´
100
´
1.5mm 3 Al heat sink.
R
P
S
C
U
m
t
m
Q
c
I C
3
8
m
C
l
5
5
5
d
V
g
V
O
l
b
o
s
c
7
d
O
p
P O 1
T
R
L =
W
5
5
W
P O 2
T
R
L =
W
9
W
Continued on next page
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)/O281TS/D177KI/5085MW/6250KI, TS No.556–1/10
t
£
11028124.005.png 11028124.006.png
 
LA4422
Continued from preceding page.
R
P
S
C
U
m
t
m
T
h
d
T
P O =
0
2
%
I
r
r
3
W
O
n
v
V
N
R
W
,
n
f
1
2
m
Equivalent Circuit Block Diagram
Proper Cares in Using IC
1. Maximum ratings
Extreme caution should be excrcised when using the IC in the vicinity of the maximum ratings as a slight factor may
cause the maximum ratings to be exceeded, thereby leading to a breakdown accident.
2. Pin-to-pin short
If the power supply is truned ON with pin-to-pin short, a breakdown or de-gradation may occur. When installing the IC
on the board, be sure to check that pin-to-pin area is not shorted with solder, etc. and turn ON the power supply.
3. Printed Circuit Board
When designing the printed circuit board, make the power supply and ground lines thicker and shorter so that no
feedback loop of input/output is formed. When using under the condition where the signal source impedance (Rg) is
large, a stable operation against distortion is obtained by separating the input /output ground line at the root of GND pin
[pin (8)]. The heat sink fin must be reliably connected to the external line of the same potential as pin (8) (GND).
No.556–2/10
k
11028124.007.png
LA4422
Functions of External Parts
The recommended number of external parts of the LA4422 is 4 pcs. as follows.
· Feedback capacitor from pin (5) C NF .
· Pin (7) to (10) bootstrap capacitor C BS .
· Output capacitor from pin (10) C OUT .
· High frequency parasitic oscillation compensating capacitor C X .
The fixed values of these parts are C NF =100
m
F, C BS =100
m
F, C OUT =1000
m
F, C X =0.15
m
F. We now consider what will occur
when these values are changed.
(a) Feedback capacitor C NF
If C NF is made smaller, the combined series impedance with R NF at a low frequency is increased, the amplification
degree A vf is decreased, and the low cutoff frequency is made higher as seen from the following equation.
Avf=
Rf
1
(R NF + )
j
w
C NF
VG=20log Avf (dB)
The ripple rejection is also lowered. It is possible, however, to make the starting time earlier at the time of the power
supply switch ON. If C NF is made larger, these are reversed.
(b) Bootstrap capacitor C BS
The low cutoff frequency may be somewhat influenced, but the drive at a low frequency is more influenced. If C BS is
made smaller, power at a low frequency may be reduced. Therefore, C BS should be more than 47
F.
(c) Output capacitor C OUT
The low cutoff frequency may be somewhat influenced, but the most influence is that power is reduced as the imped-
ance at a low frequency is increased. Therefore, C OUT should be determined by the power band width. 470
F min. is
required.
(d) High frequency parasitic oscillation compensating capacitor C X .
C X should be a polyester film capacitor of good frequency characteristic. If a ceramic capacitor is used, oscillation may
occur.
and the cutoff frequency point f L is considered so that the
frequency characteristic is fully externded to a low frequency even if the capacity of capacitor C NF is small.
· The high frequency parasitic oscillation compensating capacitor is built in as a means to reduce the number of external
parts. Therefore, the high cutoff frequency point f H is fixed.
· The feedback resistor R NF is built in and the voltage gain is fixed to be 53dB in order to reduce the number of external
parts and to minimize the variations of voltage gain.
Pins (5) and (6) are provided to control the voltage gain externally. The voltage gain is lowered by inserting a resistor in
series with pin (5). The voltage gain is increased by inserting a resistor between pin (5) and (6). If CR are connected to
pin (6), the voltage gain is freely controlled through pin (6) alone.
· Pin (4) is provided as a decoupling pin.
Even if the power suppy is turned ON/OFF in succession, pop noise is minimized by connecting a capacitor to this pin,
provided that a condition C D ³
W
C NF is recommended. C NF is related to the starting time. The ripple rejection is improved
by connecting the decoupling capacitor C D .
No.556–3/10
m
m
Features of IC System and Functions of Remaining Pins
· Since the input circuit uses pnp and the input potential is designed to be 0 bias, no input coupling capacitor is needed and
the direct coupling is available.
· The thermal shutdouwn protection circuit is built in to prevent breakdown or degradation attributable to generation of heat
at the time of load short or overload.
· The overvoltage protection circuit is built in to protect the IC from breaking down when a surge is applied to the power
supply line.
· The prevention circuit is provided to prevent pop noise which occures when the power supply is turned ON.
· The voltage gain of open loop is lowered and the nagative feedback is made smaller to obtain a soft clip. Radiation to the
high frequency circuit and stability are considered.
· The feedback resistor R f is set up at such a large value as 40k
11028124.001.png 11028124.002.png
LA4422
Sample Application Circuit 1. Power amplifier for 5.8W typ. car radio, car stereo
No.556–4/10
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LA4422
No.556–5/10
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