Ordering number : ENN6630
O3100RM (OT) No. 6630-1/9
Overview
The LA4743B is a 45 W 4-channel power amplifier IC for
car stereo systems. It features a built-in bridge circuit and
the ability to radically reduce the number of external
components required. It is also pin compatible with the
LA4743A, which differs in the amount of gain provided.
Features
Maximum output power: 45 W
4 channels
(V
CC
= 14.4 V, 4
load, 1 kHz)
40 W
4 channels (V
CC
= 13.7 V, 4
load, 1 kHz)
Requires only seven external components and does not
require an oscillation prevention RC circuit, a noise
filter, or a BS capacitor.
Functions
Muting function
Built-in standby switch
Full complement of built-in protection circuits,
including protection from shorting to V
CC
, shorting to
ground, load shorting, overvoltages, and overheating.
Package Dimensions
unit: mm
3236-HZIP25
2.0
2.0
29.2
2.60
(1.0)
25.6
0.53
R1.7
0.4
17.4
14.4
4.5
10.2
3.3
4.0
4.0
SANYO: HZIP25
[LA4743B]
LA4743B
SANYO Electric Co.,Ltd. Semiconductor Company
TOKYO OFFICE Tokyo Bldg., 1-10, 1 Chome, Ueno, Taito-ku, TOKYO, 110-8534 JAPAN
45 W Four-Channel (Bridge Circuit) Power Amplifier
Monolithic Linear IC
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.
Parameter
Symbol
Conditions
Ratings
Unit
Maximum supply voltage
V
CC
max1
Signal present
18
V
V
CC
max2
No signal (for 1 minute)
26
V
Maximum output current
I
O
peak
4.5/ch
A
Allowable power dissipation
Pd max
With an arbitrarily large heat sink
50
W
Operating temperature
Topr
40 to +85
C
Storage temperature
Tstg
40 to +150
C
Package thermal resistance
jc
1
C/W
Specifications
Maximum Ratings
at Ta = 25C
No. 6630-2/9
LA4743B
Parameter
Symbol
Conditions
Ratings
Unit
min
typ
max
Quiescent current
I
CCO
R
L
=
, Rg = 0
100
200
350
mA
Standby current
Ist
Vst = 0 V
10
A
Output offset voltage
V
N
offset
Rg = 0
150
+150
mV
Voltage gain
VG
V
O
= 0 dBm
31
32
33
dB
Voltage gain difference
VG
1
+1
dB
P
O
1
THD = 10 %
23
28
W
Output power
P
O
max1
V
CC
= 13.7 V, V
IN
= 5 Vrms
40
W
P
O
max2
V
IN
= 5 Vrms
45
W
Total harmonic distortion
THD
P
O
= 4 W
0.1
0.4
%
Channel separation
CHsep
V
O
= 0 dBm, Rg = 10 k
50
60
dB
Ripple rejection ratio
SVRR
f
r
= 100 Hz, V
R
= 0 dBm, Rg = 0
43
50
dB
Output noise voltage
V
NO
Rg = 0, B.P.F. = 20 Hz to 20 kHz
250
450
Vrms
Muting attenuation
Mute(att)
V
O
= 20 dBm
70
80
dB
Operating Characteristics
at Ta = 25C, V
CC
= 14.4 V, f = 1 kHz, R
L
= 4
, Rg = 600
Parameter
Symbol
Conditions
Ratings
Unit
Recommended supply voltage
V
CC
14.4
V
Recommended load resistance
R
L
4
Operating supply voltage range
V
CC
op
9 to 18
V
Operating Conditions
at Ta = 25C
No. 6630-4/9
LA4743B
Pin Functions and Equivalent Circuits
at V
CC
= 14.4 V, ST-BY = 5 V
Pin No.
Function
DC voltage [V]
Notes
Internal equivalent circuit
1
TAB
2
8
18
24
POWER GND
3
130
130
V
CC
5
7
9
17
19
21
23
A13504
3
5
7
9
17
19
21
23
OUT2
+OUT2
OUT1
+OUT1
+OUT3
OUT3
+OUT4
OUT4
2.7
The amplifier will be on when the
applied voltage is between 2 V and
V
CC
.
4
ST-BY
10 k
30 k
1.5 k
4
A13505
6
20
V
CC
1/2
V
CC
3/4
Low ripple power supply line for all
internal IC blocks
10
SVR
13.2
200
200
V
CC
1 k
10
A13506
Continued on next page.
Low saturation
voltage circuit
Bias circuit ST-BY power
supply line
Input amplifier ST-BY
power supply line
No. 6630-5/9
LA4743B
Continued from preceding page.
Pin No.
Function
DC voltage [V]
Notes
Internal equivalent circuit
11
12
14
15
IN1
IN2
IN4
IN3
100
1 k
5 pF
30 k
V
REF
11
12
14
15
A13507
Amplifier turn-on time control circuit
Impulse noise prevention circuit
With a 22 F capacitor, the turn-on
time will be 0.6 s.
16
ON TIME MUTE
20 k
10 k
2 k
13 k
40 k
2 k
200
V
REF
16
A13508
13
The muting function is activated when
the applied voltage is under 1 V.
22
MUTE
4.1
3 k
1 k
7.5 k
10 k
100
100 k
V
REF
V
REF
22
A13509
3.1
Input amplifiers that require no
capacitor in the input noise filter.
PRE GND
2.6
25
N.C.
Input amplifier
ST-BY power
supply line
Inverter
amplifier
Bias circuit
power supply line
Input amplifier
ST-BY power
supply line
Amplifier
bias circuit
PDF 
ZIP