Ordering number: ENN7096

SANYO Electric Co.,Ltd. Semiconductor CompanyTOKYO 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 handleapplications that require extremely high levels of reliability, such as life-support systems, aircraft’scontrol systems, or other applications whose failure can be reasonably expected to result in seriousphysical and/or material damage. Consult with your SANYO representative nearest you before usingany SANYO products described or contained herein in such applications.

SANYO assumes no responsibility for equipment failures that result from using products at values thatexceed, even momentarily, rated values (such as maximum ratings, operating condition ranges, or otherparameters) listed in products specifications of any and all SANYO products described or containedherein.

10 W 2-Channel Power Amplifier

LA4278Monolithic Linear IC

41202RM (II) No. 7096-1/6

Package Dimensionsunit: mm

3024A-SIP10H

[LA4278]

SANYO: SIP10H

OverviewThe LA4278 is a 10 W 2-channel power amplifier intendedfor televisions.This IC has a series of pin compatible monaural and 2-channel power amplifiers, thus allows the end product touse 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(VCC = 28 V/RL = 8 Ω).

SpecificationsMaximum Ratings at Ta = 25°C

Parameter Symbol Conditions Ratings Unit

Maximum supply voltage VCC Rg = 0 35 V

Maximum output current IO peak Per channel 2.5 A

Allowable power dissipation Pd max Infinite heat sink 25.0 W

Thermal resistance θ j-c 3.0 °C/W

Operating temperature Topr –20 to +75 °CStorage temperature Tstg –40 to +150 °C

Operating Conditions at Ta = 25°C

Parameter Symbol Conditions Ratings Unit

Recommended supply voltage VCC 28 V

Load resistance RL 8 ΩOperating supply voltage range VCC op Range does not exceed Pd 10 to 34 V

27.020.0

R1.

7

8.4

101

11.8

4.0

0.42.0

7.0

0.5 2.54 2.071.4

6.0

1.0

min

13.2

max

LA4278

No. 7096-2/6

Operating Characteristics at Ta = 25°C, VCC = 28 V, RL = 8 Ω, f = 1 kHz, Rg = 600 Ω, with specified board, inspecified circuit

Parameter Symbol ConditionsRatings

min typ max Unit

Quiescent current ICCO Rg = 0 55 80 mA

Voltage gain VG VO = 0 dBm 38 40 42 dB

Total harmonic distortion THD PO = 0.5 W 0.1 0.8 %

Output noise voltage VNO Rg = 10 kΩ, BPF = 20 Hz to 20 kHz 0.25 1.0 mV

Output power PO THD = 10 % 8.0 10 W

Ripple rejection SVRR Rg = 0, fr = 100 Hz, Vr = 0.5 Vrms 45 55 dB

Crosstalk CT Rg = 10 kΩ, VO = 0 dBm 40 55 dB

0

Ambient temperature, Ta — ¡C

Pd max – Ta

Allo

wab

le p

ower

dis

sipa

tion,

Pd

max

— W

ILA00880

--20

28

24

16

20

8

12

43.2

12.5

7

2525

7.5

4.2

1.92

200 40 60 80 160140120100

Infinite heat sink

100 × 100 × 1.5 mm3

50 × 50 × 1.5 mm3

No heat sink

AI heat sink Mounting torque 39N¥cm Flat washer Silicone grease applied

Pin Assignment and Equivalent Circuit Diagram

* For Muting, add a resistor between pin 3 and GND. 750 Ω for the LA4266/67/68, 200 Ω for the LA4276/77.

+

+

+ +

30 kΩ

300

Ω

NF1 IN1 Filter PRE GND IN2 NF2 OUT2 Power GND VCC OUT1

C1

100

µF

C4

4.7

µF

C5

100

µF

C6

1000

µF

C7

0.1

µFR

21.

0 Ω

C8

1000

µF

RL

1 2 3 4 5 6 7 8 9 10

+ +

30 kΩ300 Ω

+

C2

4.7

µFC

310

0 µF

R1

750

Ω

C9

1000

µF

C10

0.1

µF

RL

R3

1.0

Ω

LA4278

No. 7096-3/6

Description of External PartsC1, C5: Feedback capacitors

Decreasing the capacitance value lowers the low frequency response. Increasing the capacitance value makes thestarting time later.

C2, C4: Input capacitorsBecause the DC potential of the input pin is not zero, this capacitor can not be omitted. Decreasing the capacitancevalue to an extremely low level lowers the low frequency response.

C3: Ripple filter capacitorDecreasing the capacitance value reduces ripple rejection. This capacitor also affects the starting time; decreasingthe capacitance value makes the starting time earlier.

C6, C9: Output capacitorsDecreasing the capacitance value causes insufficient power at low frequencies.

C7, C10: Oscillation blocking capacitorsDecreasing the capacitance value causes oscillation to occur easily. Use a mylar film capacitor that has good highfrequency response and temperature characteristics. The use of an electrolytic capacitor or a ceramic capacitor maycause oscillation to occur at low temperatures.

C8: Power capacitorDecreasing the capacitance value causes ripple to occur easily. Locating this capacitor at a distance from the IC orremoving this capacitor may cause oscillation to occur.

R1: Muting resistorRefer to supplementary discussion “External Muting.”

R2, R3: Resistors connected in series with oscillation blocking capacitorThese prevent phase shift in conjunction with the oscillation blocking capacitor so that oscillation does not easilyoccur. There is an optimal value for the resistor; increasing or decreasing the resistance causes oscillation to occureasily.

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 3and GND. If the resistance value of R3 is too low, a popping noise is generated; ifthe resistance value is too high, the muting effect is reduced. (A value of 750 Ω isrecommended for R3.)

Voltage GainThe voltage gain is fixed at 40dB by the ratio of the 30 kΩ and 300 Ωinternal resistors. Therefore, it is not possible to use this IC with avoltage gain greater than 40 dB. Although it is possible to use this ICwith a voltage gain of less than 40 dB by adding a feedback resistor(RNF) and external resistors (R) as shown in the diagram, doing socauses oscillation to occur easily. Therefore, do not use this IC with avoltage gain of 30dB or less.

+

IN1 Filter PRE GND

2 3 4

C3

R3

Mute SW

+

+ +

Rf 30 kΩ

300

Ω

IN1/2 NF1/2 OUT1/2

C2/C4RL

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 couldcause the maximum ratings to be exceeded, damaging the IC. Therefore, allow for an adequate safety margin inregards to supply voltage, etc., so that the IC is never used under conditions that exceed its maximum ratings.

• Short circuit between pinsApplying 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 circuitbetween any of the pins before applying power to the IC.

• Using the IC in a radioWhen using this IC in a radio, make sure that there is enough distance between the IC and the bar antenna.

• Printed circuit patternWhen designing the printed circuit pattern, keep power, output, and ground lines thick and short, and determine theplacement 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 aspossible to the IC pins in order to prevent oscillation.

LA4278

No. 7096-5/6

00

10

20

30

5

40

60

50

10 20 2515 30 40 4535Supply voltage, VCC — V

ICCO – VCCQ

uies

cent

cur

rent

, IC

CO

— m

A

ILA00881

Output power, PO — W

THD – PO

Tota

l har

mon

ic d

isto

rtio

n, T

HD

-- %

ILA00884Frequency, f — Hz

THD – f

Tota

l har

mon

ic d

isto

rtio

n, T

HD

— %

ILA00883

80

2

4

6

8

14

12

10

1612 28 32 3620 24Supply voltage, VCC — V

PO – VCC

Sup

ply

volta

ge, P

O —

W

ILA00882

RL = 8 Ωf = 1 kHzTHD = 10%

Rg = 0RL = 8 Ω

0.1 1.02 3 5 7 102 3 5 7

10

75

32

75

32

75

32

32

1.0

0.1

0.0110 1002 3 5 7 2 3 5 7 2 3 5 7 2 3 5 71 k 10 k 100 k

75

3

2

3

2

1.0

0.175

3

2

0.1

0.1 1.02 3 5 73 5 7

7

5

3

2

1.0

0.1

Frequency, f — Hz

Response – f

Res

pons

e —

dB

ILA0088510 1002 3 5 7 2 3 5 7 2 3 5 7 2 3 5 71 k 100 10 k1 k 100 k2 3 5 7 2 3 5 7 2 3 5 710 k 100 k

0

--1

--2

--3

--4

--5

1

0

0.1

0.2

0.3

0.4

Input signal source resistance, Rg — Ω

VNO – Rg

Out

put n

oise

vol

tage

, VN

O —

mV

rms

ILA00886

Ripple voltage, Vr — V

Vro – Vr

Out

put r

ippl

e vo

ltage

, Vro

— m

Vrm

s

ILA00887

VCC = 28 VRL = 8 ΩPO = 0.5 W

VCC = 28 VRg = 0fr = 100 Hz

VCC = 28 VRL = 8 Ω

f=10kHz

f=1kHz

f=100Hz

VCC = 28 VRL = 8 ΩVO = 0f = 1 kHz

VCC = 28 VRL = 8 ΩDIN Audio

Frequency, f — Hz

CT – f

Cro

ssta

lk, C

T —

dB

ILA00888

10 1002 3 5 7 2 3 5 7 2 3 5 7 2 3 5 71 k 10 k 100 k

70

60

50

40

30

80VCC = 28 VRL = 8 ΩRg = 10 kΩVO = 0

CH2→CH1

CH1→CH2

LA4278

PS No. 7096-6/6

Output power, PO – W

Pd – PO

Pow

er d

issi

patio

n, P

d –

W

ILA00889

0.1 1.02 3 5 7 102 3 5 7

12

10

8

6

2

4

0

VCC = 28 RL = 8 Ωf = 1 kHzPd = 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 guaranteesof the performance, characteristics, and functions of the described products as mounted in the customer’sproducts 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 allsemiconductor products fail with some probability. It is possible that these probabilistic failures couldgive 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 sothat these kinds of accidents or events cannot occur. Such measures include but are not limited to protectivecircuits 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 containedherein are controlled under any of applicable local export control laws and regulations, such products mustnot be exported without obtaining the export license from the authorities concerned in accordance with theabove law.

No part of this publication may be reproduced or transmitted in any form or by any means, electronic ormechanical, 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 toproduct/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 notguaranteed for volume production. SANYO believes information herein is accurate and reliable, butno guarantees are made or implied regarding its use or any infringements of intellectual property rightsor other rights of third parties.

This catalog provides information as of April, 2002. Specifications and information herein are subject tochange without notice.