Ordering number: ENN7096
SANYO Electric Co.,Ltd. Semiconductor Company
TOKYO OFFICE Tokyo Bldg., 1-10, 1 Chome, Ueno, Taito-ku, TOKYO, 110-8534 JAPAN
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.
10 W 2-Channel Power Amplifier
LA4278
Monolithic Linear IC
41202RM (II) No. 7096-1/6
Package Dimensions
unit: mm
3024A-SIP10H
[LA4278]
SANYO: SIP10H
Overview
The LA4278 is a 10 W 2-channel power amplifier intended
for televisions.
This IC has a series of pin compatible monaural and 2-
channel power amplifiers, thus allows the end product to
use a common circuit boad.
Features
Television audio output.
Pin compatible with the LA4266 (3 W)/LA4267 (5 W)/
4268 (10 W) and the LA4276 (3 W
2)/4277(5 W 2).
Package: SIP-10H (2.54 mm pitch, straight pins).
Thermal protection circuit and overvoltage protection
circuit on chip.
Output power: 10 W
2(V
CC
= 28 V/R
L
= 8
).
Specifications
Maximum Ratings at Ta = 25
C
Parameter
Symbol
Conditions
Ratings
Unit
Maximum supply voltage
V
CC
Rg = 0
35
V
Maximum output current
I
O
peak
Per channel
2.5
A
Allowable power dissipation
Pd max
Infinite heat sink
25.0
W
Thermal resistance
j-c
3.0
C/W
Operating temperature
Topr
20 to +75
C
Storage temperature
Tstg
40 to +150
C
Operating Conditions at Ta = 25
C
Parameter
Symbol
Conditions
Ratings
Unit
Recommended supply voltage
V
CC
28
V
Load resistance
R
L
8
Operating supply voltage range
V
CC
op
Range does not exceed Pd
10 to 34
V
27.0
20.0
R1.7
8.4
10
1
11.8
4.0
0.4
2.0
7.0
0.5
2.54
2.07
1.4
6.0
1.0
min
13.2max
LA4278
No. 7096-2/6
Operating Characteristics at Ta = 25
C, V
CC
= 28 V, R
L
= 8
, f = 1 kHz, Rg = 600 , with specified board, in
specified circuit
Parameter
Symbol
Conditions
Ratings
min
typ
max
Unit
Quiescent current
I
CCO
Rg = 0
55
80
mA
Voltage gain
VG
V
O
= 0 dBm
38
40
42
dB
Total harmonic distortion
THD
P
O
= 0.5 W
0.1
0.8
%
Output noise voltage
V
NO
Rg = 10 k
, BPF = 20 Hz to 20 kHz
0.25
1.0
mV
Output power
P
O
THD = 10 %
8.0
10
W
Ripple rejection
SVRR
Rg = 0, f
r
= 100 Hz, Vr = 0.5 Vrms
45
55
dB
Crosstalk
CT
Rg = 10 k
, V
O
= 0 dBm
40
55
dB
0
Ambient temperature, Ta -- C
Pd max Ta
Allowable power dissipation, Pd max
--
W
ILA00880
--20
28
24
16
20
8
12
4
3.2
12.5
7
25
25
7.5
4.2
1.92
20
0
40
60
80
160
140
120
100
Infinite heat sink
100
100 1.5 mm
3
50
50 1.5 mm
3
No heat sink
AI heat sink
Mounting
torque 39Ncm
Flat washer
Silicone grease
applied
Pin Assignment and Equivalent Circuit Diagram
* For Muting, add a resistor between pin 3 and GND. 750
for the LA4266/67/68, 200 for the LA4276/77.
+
+
+
+
30 k
300
NF1
IN1
Filter
PRE GND
IN2
NF2
OUT2 Power GND
VCC
OUT1
C1
100
F
C4
4.7
F
C5
100
F
C6
1000
F
C7
0.1
F
R2
1.0
C8
1000
F
RL
1
2
3
4
5
6
7
8
9
10
+
+
30 k
300
+
C2
4.7
F
C3
100
F
R1
750
C9
1000
F
C10
0.1
F
RL
R3
1.0
LA4278
No. 7096-3/6
Description of External Parts
C1, C5: Feedback capacitors
Decreasing the capacitance value lowers the low frequency response. Increasing the capacitance value makes the
starting time later.
C2, C4: Input capacitors
Because the DC potential of the input pin is not zero, this capacitor can not be omitted. Decreasing the capacitance
value to an extremely low level lowers the low frequency response.
C3: Ripple filter capacitor
Decreasing the capacitance value reduces ripple rejection. This capacitor also affects the starting time; decreasing
the capacitance value makes the starting time earlier.
C6, C9: Output capacitors
Decreasing the capacitance value causes insufficient power at low frequencies.
C7, C10: Oscillation blocking capacitors
Decreasing the capacitance value causes oscillation to occur easily. Use a mylar film capacitor that has good high
frequency response and temperature characteristics. The use of an electrolytic capacitor or a ceramic capacitor may
cause oscillation to occur at low temperatures.
C8: Power capacitor
Decreasing the capacitance value causes ripple to occur easily. Locating this capacitor at a distance from the IC or
removing this capacitor may cause oscillation to occur.
R1: Muting resistor
Refer to supplementary discussion "External Muting."
R2, R3: Resistors connected in series with oscillation blocking capacitor
These prevent phase shift in conjunction with the oscillation blocking capacitor so that oscillation does not easily
occur. There is an optimal value for the resistor; increasing or decreasing the resistance causes oscillation to occur
easily.
External Muting
Pull down the electric potential of the ripple filter pin (pin 3).
Muting becomes possible by inserting the discharge resistor R3 between pin 3
and GND. If the resistance value of R3 is too low, a popping noise is generated; if
the resistance value is too high, the muting effect is reduced. (A value of 750
is
recommended for R3.)
Voltage Gain
The voltage gain is fixed at 40dB by the ratio of the 30 k
and 300
internal resistors. Therefore, it is not possible to use this IC with a
voltage gain greater than 40 dB. Although it is possible to use this IC
with a voltage gain of less than 40 dB by adding a feedback resistor
(RNF) and external resistors (R) as shown in the diagram, doing so
causes oscillation to occur easily. Therefore, do not use this IC with a
voltage gain of 30dB or less.
+
IN1
Filter
PRE GND
2
3
4
C3
R3
Mute SW
+
+
+
Rf 30 k
300
IN1/2
NF1/2
OUT1/2
C2/C4
RL
5
6
7
R
C1/C5
C6/C9
C7/C10
R2/R3
RNF
(1)
(2)
(10)
LA4278
No. 7096-4/6
Notes on Using the IC
Maximum ratings
When this IC is used near its maximum ratings, it is possible that a slight fluctuation in the operating conditions could
cause the maximum ratings to be exceeded, damaging the IC. Therefore, allow for an adequate safety margin in
regards to supply voltage, etc., so that the IC is never used under conditions that exceed its maximum ratings.
Short circuit between pins
Applying power to the IC while a short circuit exists between two pins can cause damage or deterioration in the IC.
Therefore, after mounting the IC on a board, make sure that there are no solder bridges, etc., causing a short circuit
between any of the pins before applying power to the IC.
Using the IC in a radio
When using this IC in a radio, make sure that there is enough distance between the IC and the bar antenna.
Printed circuit pattern
When designing the printed circuit pattern, keep power, output, and ground lines thick and short, and determine the
placement of the pattern and the components in such a way as to prevent the generation of an I/O feedback loop.
In addition, power supply capacitor C8 and oscillation blocking capacitor C7 and C10 should be placed as close as
possible to the IC pins in order to prevent oscillation.
LA4278
No. 7096-5/6
0
0
10
20
30
5
40
60
50
10
20
25
15
30
40
45
35
Supply voltage, VCC -- V
ICCO VCC
Quiescent current, I
CCO
--
mA
ILA00881
Output power, PO -- W
THD PO
T
otal harmonic distortion,
THD -
-
%
ILA00884
Frequency, f -- Hz
THD f
T
otal harmonic distortion,
THD
--
%
ILA00883
8
0
2
4
6
8
14
12
10
16
12
28
32
36
20
24
Supply voltage, VCC -- V
PO
VCC
Supply voltage, P
O
--
W
ILA00882
RL = 8
f = 1 kHz
THD = 10%
Rg = 0
RL = 8
0.1
1.0
2
3
5
7
10
2
3
5
7
10
7
5
3
2
7
5
3
2
7
5
3
2
3
2
1.0
0.1
0.01
10
100
2 3
5 7
2 3
5 7
2 3
5 7
2 3
5 7
1 k
10 k
100 k
7
5
3
2
3
2
1.0
0.1
7
5
3
2
0.1
0.1
1.0
2
3
5
7
3
5
7
7
5
3
2
1.0
0.1
Frequency, f -- Hz
Response f
Response
--
dB
ILA00885
10
100
2 3
5 7
2 3
5 7
2 3
5 7
2 3
5 7
1 k
100
10 k
1 k
100 k
2
3
5
7
2
3
5
7
2
3
5
7
10 k
100 k
0
--1
--2
--3
--4
--5
1
0
0.1
0.2
0.3
0.4
Input signal source resistance, Rg --
VNO Rg
Output noise voltage, VNO
--
mV
rms
ILA00886
Ripple voltage, Vr -- V
Vro Vr
Output ripple voltage, V
ro
--
mV
rms
ILA00887
VCC = 28 V
RL = 8
PO = 0.5 W
VCC = 28 V
Rg = 0
fr = 100 Hz
VCC = 28 V
RL = 8
f=10kHz
f=1kHz
f=100Hz
VCC = 28 V
RL = 8
VO = 0
f = 1 kHz
VCC = 28 V
RL = 8
DIN Audio
Frequency, f -- Hz
CT f
Crosstalk, CT
--
dB
ILA00888
10
100
2
3
5 7
2
3
5 7
2
3
5 7
2
3
5 7
1 k
10 k
100 k
70
60
50
40
30
80
VCC = 28 V
RL = 8
Rg = 10 k
VO = 0
CH2
CH1
CH1
CH2
LA4278
PS No. 7096-6/6
Output power, PO W
Pd PO
Power dissipation, Pd
W
ILA00889
0.1
1.0
2
3
5
7
10
2
3
5
7
12
10
8
6
2
4
0
VCC = 28
RL = 8
f = 1 kHz
Pd = VCC ICC 2 PO
0
ILA00962
0
0
ILA00961
0
0.5 s/DIV
Pop noise waveform (1 V/DIV)
Middle point rise waveform (5 V/DIV)
Power on output waveform
SP terminal AC
Output DC
0.5 s/DIV
Pop noise waveform (1 V/DIV)
Middle point fall waveform (5 V/DIV)
Power off output waveform
Specifications of any and all SANYO products described or contained herein stipulate the performance,
characteristics, and functions of the described products in the independent state, and are not guarantees
of the performance, characteristics, and functions of the described products as mounted in the customer's
products or equipment. To verify symptoms and states that cannot be evaluated in an independent device,
the customer should always evaluate and test devices mounted in the customer's products or equipment.
SANYO Electric Co., Ltd. strives to supply high-quality high-reliability products. However, any and all
semiconductor products fail with some probability. It is possible that these probabilistic failures could
give rise to accidents or events that could endanger human lives, that could give rise to smoke or fire,
or that could cause damage to other property. When designing equipment, adopt safety measures so
that these kinds of accidents or events cannot occur. Such measures include but are not limited to protective
circuits and error prevention circuits for safe design, redundant design, and structural design.
In the event that any or all SANYO products (including technical data, services) described or contained
herein are controlled under any of applicable local export control laws and regulations, such products must
not be exported without obtaining the export license from the authorities concerned in accordance with the
above law.
No part of this publication may be reproduced or transmitted in any form or by any means, electronic or
mechanical, including photocopying and recording, or any information storage or retrieval system,
or otherwise, without the prior written permission of SANYO Electric Co., Ltd.
Any and all information described or contained herein are subject to change without notice due to
product/technology improvement, etc. When designing equipment, refer to the "Delivery Specification"
for the SANYO product that you intend to use.
Information (including circuit diagrams and circuit parameters) herein is for example only; it is not
guaranteed for volume production. SANYO believes information herein is accurate and reliable, but
no guarantees are made or implied regarding its use or any infringements of intellectual property rights
or other rights of third parties.
This catalog provides information as of April, 2002. Specifications and information herein are subject to
change without notice.
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