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Ordering number: EN3848D
Monolithic Linear IC
LA4705
15 W 2-channel BTL AF Power Amplifier
for Car Stereos
Overview
The LA4705 is a BTL two-channel power IC for car audio and
radio-cassette players developed in pursuit of excellent sound
quality. Low-region frequency characteristics have been
improved through the use of a new NF capacitorless circuit,
and crosstalk which causes ‘‘muddy’’ sound has been reduced
by improving both circuit and pattern layout. As a result, the
LA4705 provides powerful bass and clear treble. In addition,
the LA4705 features on-chip protectors and standby switch.
Features
.
High power: supports total output of 25 W + 25 W
(V
= 14.4 V, THD = 30%, RL=4Ω)
CC
.
Less pop noise
.
Designed for excellent sound quality
(f
< 10 Hz, fH= 130 kHz)
L
.
Any on time settable by external capacitor
.
Standby switch circuit on chip (microprocessor supported)
.
Various protectors on chip
(output-to-ground short/output-to-V
load short/overvoltage/thermal shutdown circuit)
.
NF capacitorless
.
Supports RL=2Ω
CC
short/
Package Dimensions
unit: mm
3109-SIP18H
[LA4705]
SANYO : SIP18H
Specifications
Maximum Ratings at Ta = 25°C
Parameter Symbol Conditions Ratings Unit
Maximum supply voltage V
Surge supply voltage V
Allowable power dissipation Pd max Arbitrarily large heat sink 37.5 W
Operating temperature Topr –35 to +85 °C
Storage temperature Tstg –40 to +150 °C
* Set VCC,RLin a range that does not exceed Pd max = 37.5 W
max 1 No signal,t=60s 24 V
CC
V
max 2 With signal 18 V
CC
surge t % 0.2 s, single giant pulse 50 V
CC
SANYO Electric Co.,Ltd. Semiconductor Bussiness Headquarters
TOKYO OFFICE Tokyo Bldg., 1-10, 1 Chome, Ueno, Taito-ku, TOKYO, 110 JAPAN
D3096HA(II)/12693TS/4152TS No.3848-1/8
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LA4705
Operating Conditions at Ta = 25°C
Parameter Symbol Conditions Ratings Unit
Recommended supply voltage V
Operating voltage range V
Recommended load resistance R
CC
op Range where Pd max is not exceeded 9 to 18 V
CC
L
Operating Characteristics at Ta = 25°C, VCC= 13.2 V, RL=4Ω,f=1kHz, Rg = 600 Ω
Parameter Symbol Conditions min typ max Unit
Quiescent current I
Standby current Ist 10 60 µA
Voltage gain VG 38 40 42 dB
Total harmonic distortion THD P
Output power
Output offset voltage V
Output noise voltage V
Ripple rejection ratio SVRR Rg = 0, f
Channel separation CHsep Rg = 10 kΩ,V
Input resistance r
Standby pin applied voltage Vst Amp on, applied through 10 kΩ 2.5 V
CCO
= 1 W 0.1 0.4 %
1 THD = 10% 11 15 W
P
O
P
2 THD = 10%, VCC= 14.4 V 18 W
O
P
3 THD = 10%, RL=2Ω 16 W
O
offset Rg = 0 –300 +300 mV
N
NO
i
O
Rg = 0, B.P.F. = 20 Hz to 20 kHz 0.1 0.5 mVrms
= 100 Hz, VR= 0 dBm 40 50 dB
R
= 0 dBm 50 60 dB
O
13.2 V
4 Ω
80 115 250 mA
21 30 39 kΩ
CC
V
Allowable power dissipation, Pd max – W
Pd max – Ta
Arbitrarily large heat sink
Ambient temperature, Ta – °C
– °C/W
f
Heat sink thermal resistance, θ
θ
f–Sf
Al heat sink, t = 1.5 mm
Tightening torque 39 Nccm
With silicone grease applied
Heat sink area, Sf–cm
2
No.3848 -2/8
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LA4705
Features and Usage Notes
.
Pin 5 is the standby switch pin. The amplifier is turned on by applying approximately 2 V or more to this pin through an
external resistor (R1). The current flowing into pin 5 is 500 µA or less.
.
Pin 6 is the mute pin. The amplifier on time can be set as desired through C3. By grounding pin 6, the amplifier can implement
mute operation. In this case, the recovery time depends on C3.
.
In order to prevent damage or degradation which may be caused by abnormally heated IC, the LA4705 has a thermal shutdown
protector. Accordingly, in the case of inadequate heat dissipation, the thermal shutdown protector will operate to control the
output gradually into attenuation.
.
Also be fully careful of handling other protectors built in the LA4705.
Sample Application Circuit
Unit (resistance: Ω, capacitance: F)
No.3848 -3/8
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Sample Print Pattern
LA4705
Copper foil area 90 × 105 mm
2
Description of External Components
C1, C4 Input capacitors 2.2 µF is recommended. fLcan be varied by C1, C4 capacitances to adjust the
C2 Decoupling capacitor
(ripple filter)
C3 Amplifier on time setting
capacitor
C5 Power supply capacitor
C6, C7, C8, C9 Oscillation blocking capacitors Use polyester film capacitors (Mylar capacitors) with good temperature
R1 Standby switch current limiting
resistor
bass range.
Approximately 0.6 to 0.7 second for 33 µF. Since the on time is proportional to
this capacitance, it can be set as desired by varying this capacitance. The
amplifier can implement mute operation by setting C3 to GND potential.
characteristics. (R2, R3, R4, and R5 used jointly.) Since stability may be
affected slightly by the pattern layout, etc., 0.1 µF or more is recommended.
10 kΩ is recommended. This resistor cannot be removed.
No.3848 -4/8
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LA4705
–W
O
Output power, P
–W
O
PO–V
IN
Input level, VIN– Vrms
PO–V
CC
–W
O
Output power, P
PO–V
CC
Supply voltage, VCC–V
THD–P
O
Output power, P
Total harmonic distortion, THD – %
Supply voltage, VCC–V
THD–P
Total harmonic distortion, THD – %
O
Total harmonic distortion, THD – %
Output power, PO–W
Output power, PO–W
THD–P
O
Output power, PO–W
THD – f f Response
0dBm=VG40dB
Response – dB
Total harmonic distortion, THD – %
Input frequency,f–Hz
Input frequency,f–Hz
No.3848 -5/8
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LA4705
CH sep – f P
–f
O
–W
O
Output power, P
Channel separation, CHsep – dB
Input frequency,f–Hz
SVRR – V
CC
Input frequency,f–Hz
SVRR – f
Ripple rejection ratio, SVRR – dB
Supply voltage, VCC–V
SVRR – V
CCR
Ripple rejection ratio, SVRR – dB
Ripple frequency,f–Hz
V
–Rg
NO
– mVrms
NO
Ripple rejection ratio, SVRR – dB
Power supply ripple voltage, V
Pd, I
CC–PO
CCR
– Vrms
–A
CC
Output noise voltage, V
Input resistance, Rg – Ω
Pd, I
CC–PO
Package allowed power dissipation
–A
CC
Power dissipation, Pd – W
Output power, PO–W
Current drain, I
Power dissipation, Pd – W
Current drain, I
Output power, PO–W
No.3848 -6/8
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LA4705
Power dissipation, Pd – W
–V
N
Pd, I
CC–PO
Output power, PO–W
V
N–VCC
–A
CC
Current drain, I
–mA
CCO
Quiescent current, I
–mA
CCO
No load
No load
I
CCO–VCC
Supply voltage, VCC–V
–Ta
I
CCO
Output pin voltage, V
–W
O
Output power, P
Supply voltage, VCC–V
–Ta
P
O
Ambient temperature, Ta – °C
Amp ON time – C4
Quiescent current, I
Total harmonic distortion, THD – %
–V
N
Ambient temperature, Ta – °C
THD–Ta
Ambient temperature, Ta – °C
V
N–VST
Amp ON time – s
Output pin voltage, V
Unit (resistance: Ω)
C4–µF
Standby pin applied voltage, VST–V
No.3848 -7/8
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LA4705
BTL output DC locus
BTL output DC locus
AC Level
Locus when ON
AC Level
Locus when OFF
No products described or contained herein areintendedforuse in surgical implants, life-support systems, aerospace equipment,
nuclear power control systems, vehicles, disaster/crime-prevention equipment and the like, the failure of which may directly or
indirectly cause injury, death or property loss.
Anyone purchasing any products described or contained herein for an above-mentioned use shall:
1 Accept full responsibility and indemnify and defend SANYO ELECTRIC CO., LTD., its affiliates, subsidiaries and distributors
and all their officers and employees, jointly and severally, against any and all claims and litigation and all damages, cost and
expenses associated with such use:
2 Not impose any responsibility for any fault or negligence which may be cited in any such claim or litigation on SANYO
ELECTRIC CO., LTD., its affiliates, subsidiaries and distributors or any of their officers and employees jointly or severally.
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 December, 1996. Specifications and information herein are subject to change without notice.
No.3848 -8/8
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