LA4708 [SANYO]
20 W 2-channel BTL AF Power Amplifier for Car Stereos; 20瓦2声道BTL AF功率放大器汽车音响
| 型号： | LA4708 |
| 厂家： | 
SANYO SEMICON DEVICE |
| 描述： | 20 W 2-channel BTL AF Power Amplifier for Car Stereos |
| 文件： | 总9页 (文件大小：205K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
Ordering number: EN5245A
Monolithic Linear IC
LA4708
20 W 2-channel BTL AF Power Amplifier
for Car Stereos
Overview
Package Dimensions
unit: mm
The LA4708 is a BTL two-channel power IC for car audio
developed in pursuit of excellent sound quality. Low-region
3109-SIP18H
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 LA4708 provides powerful
bass and clear treble. In addition, the LA4708 features on-chip
protectors and standby switch. The LA4708 is also
[LA4708]
pin-compatible with the LA4705NA (car stereo-use 17 W
two-channel power IC), and can be substituted for the
LA4705NA for higher power. (When the board is shared, pins
1 and 9 must be left open.)
Features
.
.
.
High power: supports total output of 30 W + 30 W
(VCC = 13.2 V, THD = 30%, RL = 4 Ω)
Supports RL = 2 Ω (PO = 30 W when VCC = 13.2 V,
THD = 10%)
Designed for excellent sound quality
(fL < 10 Hz, fH = 130 kHz)
NF capacitorless
Any on time settable by external capacitor
Less pop noise
Standby switch circuit on chip (microprocessor supported)
Various protectors on chip
(output-to-ground short/output-to-VCC short/
load short/overvoltage/thermal shutdown circuit)
SANYO : SIP18H
.
.
.
.
.
Specifications
Maximum Ratings at Ta = 25°C
Parameter
Symbol
Conditions
Ratings
Unit
Maximum supply voltage
V
V
max 1
No signal, t = 60 s
24
16
V
V
CC
max 2
surge
peak
CC
Surge supply voltage
V
t % 0.2 s, single giant pulse
Per channel
50
V
CC
Maximum output current
Allowable power dissipation
Operating temperature
Storage temperature
I
4.5
A
O
Pd max
Topr
Arbitrarily large heat sink
37.5
W
°C
°C
–35 to +85
Tstg
–40 to +150
* Set VCC, RL in a range that does not exceed Pd max = 37.5 W
SANYO Electric Co.,Ltd. Semiconductor Bussiness Headquarters
TOKYO OFFICE Tokyo Bldg., 1-10, 1 Chome, Ueno, Taito-ku, TOKYO, 110 JAPAN
93096HA(II)/13096HA(II) No.5245-1/9
LA4708
Operating Conditions at Ta = 25°C
Parameter
Symbol
Conditions
Ratings
13.2
Unit
V
Recommended supply voltage
Operating voltage range
V
CC
op
V
Range where Pd max is not exceeded
9 to 16
4
V
CC
Recommended load resistance
Recommended load resistance range
R
Ω
L
R
op
2 to 4
Ω
L
Operating Characteristics at Ta = 25°C, VCC = 13.2 V, RL = 4 Ω, f = 1 kHz, Rg = 600 Ω
Parameter
Quiescent current
Symbol
Conditions
min
70
typ
150
10
max
Unit
mA
µA
dB
%
I
250
60
CCO
Ist
Standby current
Voltage gain
VG
38
16
40
42
Total harmonic distortion
THD
P 1
P
= 2 W
0.07
20
0.4
O
THD = 10%
W
O
Output power
P 2
THD = 10%, V
= 14.4 V
24
W
O
CC
P 3
THD = 10%, R = 2 Ω
30
W
O
L
Output offset voltage
Output noise voltage
Ripple rejection ratio
Channel separation
Input resistance
V
offset
Rg = 0
–300
+300
mV
N
V
Rg = 0, B.P.F. = 20 Hz to 20 kHz
0.1
50
60
30
0.5 mVrms
NO
SVRR
CHsep
Rg = 0, f = 100 Hz, V = 0 dBm
40
50
dB
dB
R
R
Rg = 10 kΩ, V = 0 dBm
O
r
21
39
kΩ
i
Standby pin applied voltage
Vst
Amp on, applied through 10 kΩ
2.5
V
V
CC
Al heat sink, t = 1.5 mm
Arbitrarily large heat sink
Tightening torque 39 Nccm
With silicone grease applied
Heat sink area, Sf — cm2
Ambient temperature, Ta — °C
No.5245 -2/9
LA4708
Equivalent Circuit Block Diagram
-
-
-
-
Pins 1,9 : Don’t use
Pin 10 : No connection
Each Pin Voltage
VCC = 13.2 V, 5 V applied through STBY = 10 kΩ, RL = 4 Ω, Rg = 0
Pin No.
Name
1
2
3
4
5
6
IN1
1.58
DC
6.55
Pre-GND
0
STBY
3.2
ON TIME
2.28
Pin voltage (V)
0.29
Pin No.
Name
7
8
9
–
10
N.C
0
11
12
–OUT 2
6.5
IN2
1.58
POP
2.08
V
2
CC
Pin voltage (V)
0.29
13.2
Pin No.
Name
13
14
+OUT 2
6.5
15
+OUT 1
6.5
16
17
–OUT 1
6.5
18
PWR–GND 2
0
PWR–GND 1
0
V
1
CC
Pin voltage (V)
13.2
No.5245 -3/9
LA4708
Sample Print Pattern
Copper foil area 90 × 105 mm2
Description of External Components
C1, C4
Input capacitors
2.2 µF is recommended. f can be varied by C1, C4 capacitances to adjust the
L
bass range.
C2
Decoupling capacitor
(ripple filter)
C3
Amplifier on time setting
capacitor
Approximately 0.8 second for 33 µF. Since the on time is proportional to this
capacitance, it can be set as desired by varying this capacitance.
(Refer to the characteristics curve.)
C5
Power supply capacitor
C6, C7, C8, C9 Oscillation blocking capacitors
Use polyester film capacitors (Mylar capacitors) with good temperature
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.
R1
Standby switch current limiting
resistor
10 kΩ is recommended (when the applied voltage for the standby switch is
2.5 V to 13.2 V). This resistor cannot be removed.
No.5245 -4/9
LA4708
Features of IC Inside and Usage Notes
Standby function
.
.
Pin 5 is the standby switch pin. The amplifier is turned on by applying approximately 2.5 V or more to this pin through an
external resistor (R1).
If voltage in excess of 13.2 V is to be applied to the standby switch, calculate the value of R1 using the following formula so
that the current flowing into pin 5 is 500 µA or less:
Applied voltage − 1.4 V
R1 =
– 10 kΩ
Pin 5 Equivalent
circuit internal IC
500 µA or less
500 µA
Standby
applied voltage
About 1.4 V
(2V
)
BE
Mute function
.
Pin 6 is the connector for the capacitor that determines the on time in order to prevent pop noise. By grounding this pin, the
amplifier can implement mute operation. In this case, the recovery time depends on C3.
How to reduce pop noise
.
Although the LA4708 reduces pop noise, an electrolytic capacitor of between 0.47 and 2.2 µF can be connected between pin 8
and the pre-GND to further reduce pop noise that occurs when power supply is turned on/off (standby switch on/off). The larger
the capacitance, the lower the frequency of pop noise, and it is barely audible, but sound residue of the sound signal is liable to
linger when power is turned off. Pin 8 is the bias pin for the output amplifier and normally is left open.
Protectors
.
In an output-to-ground and output-to-VCC short protector system configuration, if a DC resistor is connected between amplifier
output pin and GND, the protector may operate, causing the amplifier not to start operating. Therefore, as a general rule, no DC
resistor should be connected between amplifier output pin and GND.
In order to prevent damage or degradation which may be caused by abnormally heated IC, the LA4708 has a thermal shutdown
protector. Accordingly, if the IC junction temperature (Tj) climbs to around 170 to 180°C due to 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 LA4708.
Miscellaneous
.
Since pins 1 and 9, which are unused, are connected internally, they must be left open.
Pin 10 is an NC pin (no internal connection).
.
No.5245 -5/9
LA4708
Dual channel drive
Input level, VIN — mVrms
Supply voltage, VCC — V
Exceeding
Pd max
Dual channel drive
Dual channel drive
Supply voltage, VCC — V
Supply voltage, VCC — V
Dual channel drive
Dual channel drive
Output power, P — W
O
Output power, P — W
O
V
= 0 dBm at f = 1 kHz
O
Input frequency, f — Hz
Input frequency, f — Hz
No.5245 -6/9
LA4708
Dual channel drive
Input frequency, f — Hz
Input frequency, f — Hz
2200 µF
(power supply capacitor) is changed
to 0.47 µF (Mylar)
Input resistance, Rg — Ω
Supply voltage, VCC — V
The value of power supply capacitor is 0.47 µF(Mylar)
Calculate as
The value of power supply capacitor is 0.47 µF (Mylar)
Ripple frequency, f — Hz
Power supply ripple voltage, V — Vrms
CCR
R
Dual channel drive
Allowable power dissipation of package
Dual channel drive
Output power, PO — W
Output power, PO — W
No.5245 -7/9
LA4708
Supply voltage, VCC — V
Ambient temperature, Ta —
C
°
Dual channel drive
Dual channel drive
Ambient temperature, Ta —
C
Ambient temperature, Ta —
C
°
°
Apply V to standby pin (pin 5)
ST
through 10 kΩ.
(Apply to pin 5 through 10 kΩ.)
Standby pin applied voltage, VST — V
C3 — µF
No.5245 -8/9
LA4708
No products described or contained herein are intended for use 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 September, 1996. Specifications and information herein are subject to change without notice.
No.5245 -9/9
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