Ordering number : ENA0508
Monolithic Linear IC
LA47202P
Overview
Four-Channel BTL Power
Amplifier for Car Audio Systems
The LA47202P is a 4-channel BTL power amplifier IC developed for use in car audio applications. The LA47202P adopts
a pure complementary output stage circuit structure with a v-pnp transistor for the high side and an npn transistor for the
low side to provide both high output power and high quality sound.
The LA47202P integrates all the functions required for car audio applications on the same chip, including a standby switch,
a muting function, and a full complement of protection circuits. It also features a self diagnostics function.
Functions
•
High output : PO max = 47W (typ.) (VCC = 14.4V, f = 1kHz, JEITA max, RL = 4Ω)
: PO max = 29W (typ.) (VCC = 14.4V, f = 1kHz, THD = 10%, RL = 4Ω)
: PO max = 22W (typ.) (VCC = 14.4V, f = 1kHz, THD = 1%, RL = 4Ω)
•
Muting function incorporated (pin 22)
•
Built-in standby switch (pin 4)
•
Self diagnostics function incorporated (pin 25) :
Output of both output offset detection, shorting to VCC or ground and load shorting signals
•
Electric mirror noise decrease
•
Full compliment of protection circuits (shorting to VCC, shorting to ground, load shorting, overvoltage, and thermal
protection).
•
Improved oscillation stability
Note 1 : Take care to avoid wrong connection. Otherwise, IC or equipment may suffer breakdown, damage, or deterioration.
Note 2 : The protective circuit function is to avoid the abnormal state (wrong connection of the output) temporarily and does
not guarantee that IC is not broken.
These protective functions do not operate outside the operation guarantee range, and wrong connection of output
may cause breakdown of IC.
Note 3 : External parts, such as the anti-oscillation part, diode to prevent breakdown, may become necessary depending on the
set condition. Check their necessity for each set.
Any and all SANYO Semiconductor 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 Semiconductor representative
nearest you before using any SANYO Semiconductor products described or contained herein in such
applications.
SANYO Semiconductor 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 Semiconductor
products described or contained herein.
D2706 MS PC 20060809-S00002 No.A0508-1/8
LA47202P
Specifications
Maximum Ratings
at Ta = 25°C
Parameter
Maximum supply voltage
Symbol
VCC max1
VCC max2
Maximum output current
Allowable power dissipation
Operating temperature
Storage temperature
Thermal resistance between
junction cases
IO peak
Pd max
Topr
Tstg
θj-c
Conditions
Without signal, t = 1 minute
When operating
Per channel
With an iInfinitely large heat sink
Ratings
26
18
4.5
50
-40 to +85
-40 to +150
1
Unit
V
V
A
W
°C
°C
°C/W
Note) The relationship between the power dissipation (Pd) and the junction-to-case thermal resistance (θj-c), heat sink
thermal resistance (θf) and junction temperature (Tj), case temperature (Tc), and ambient temperature (Ta) is as
expressed by the following equation :
Tj = Pd (θj-c+θf) +Ta
= Pd×θj-c+Tc,
*Tc = Pd×θf+Ta
Note that Tj max must be limited with Tstg max (150°C).
Recommended Operating Ranges
at Ta = 25°C
Parameter
Recommended supply voltage
Recommended load resistance
Operating supply voltage range
Symbol
VCC
RL
VCC op
Range not exceceeding Pd max
Conditions
Ratings
14.4
4
9 to 16
Unit
V
Ω
V
Electrical Characteristics
at Ta
=
25°C, VCC = 14.4V, RL = 4Ω, f = 1kHz, Rg = 600Ω
Parameter
Quiescent current
Standby current
Voltage gain
Voltage gain difference
Output power
Symbol
ICCO
Ist
VG
∆VG
PO
PO max1
PO max2
Output offset voltage
Total harmonic distortion
Channel separation
Ripple rejection ratio
Output noise voltage
Input resistance
Mute attenuation
* 0dBm = 0.775Vrms
Vnoffset
THD
CHsep
SVRR
VNO
Ri
Matt
VO = 20dBm, mute : on
65
THD = 10%
VCC = 13.7V, JEITA max
JEITA max
Rg = 0
PO = 4W
VO = 0dBm, Rg = 10kΩ
Rg = 0, fr = 100Hz, VCCR = 0dBm
Rg = 0, BPF = 20Hz to 20kHz
55
45
-150
0.05
65
60
100
50
80
200
RL =
∞,
Rg = 0
Vst = 0V
VO = 0dBm
25
-1
24
29
42
47
+150
0.3
26
Conditions
min
Ratings
typ
200
max
400
10
27
+1
mA
µA
dB
dB
W
W
W
mV
%
dB
dB
µVrms
kΩ
dB
Unit
No.A0508-2/8
LA47202P
Block Diagram
VCC
VCC1/2
6
20
VCC3/4
0.1µF
+
2200µF
IN 1
+
0.47µF
11
+
-
+
-
9
7
OUT 1+
OUT 1-
RL
CONTROL
4700pF
IN 2
+
0.47µF
1
Protective
circuit
12
+
-
+
-
PWR GND1
8
OUT 2+
OUT 2-
RL
5
3
DC
22µF
+
10
Ripple
filter
PWR GND2
2
OFFSET
DIAG
AC GND
+
0.47µF
16
25
4.7kΩ
5V
PRE GND
13
Mute
circuit
Mute 10kΩ
22
+
1µF
OUT 3+
OUT 3-
RL
Low Level
Mute ON
IN 3
+
0.47µF
15
+
-
Protective
circuit
+
-
17
19
PWR GND3
18
OUT 4+
OUT 4-
RL
IN 4
+
0.47µF
14
+
-
+
-
21
23
STBY
+5V
ST ON
4
Standby
switch
PWR GND4
24
The components and constant values in the test circuit are used for confirmation of characteristics and do not guarantee
that the application equipment will be free from malfunction or trouble.
No.A0508-3/8
LA47202P
Description of Operation
1. Standby switch function (pin 4)
The pin 4 threshold voltage is set to about 3 VBE.
The amplifier is turned ON at the application voltage of 3.0V or more and OFF at 0.5V or less.
2. Muting function (pin 22)
When pin 22 is set to the ground potential, the LA47202P goes to the muted state. This supports implementation of an
audio muting function.
The muting function is turned on when a level of 1V or lower is applied through a 10kΩ resistor, and the function is
turned off when this pin is open.
The muting time constant can be set with an external RC circuit.
3. Self diagnostics function (pin 25)
This function detects abnormal IC states, and outputs a signal from pin 25. Applications can prevent damage to
speakers and other problems by using a microcontroller to detect the pin 25 signal and control the standby switch
accordingly.
(1) Output short-circuit to VCC/ground : Pin 25 becomes LOW.
(2) Load short-circuit
: Pin 25 repeats HIGH and LOW states according to the output signal.
(3) Output offset abnormality
: Pin 25 goes low if the OUT pin (VN) voltage becomes lower than the
detection level. Problems that can cause an output offset abnormality
include input capacitor leakage and half shorts between the input pins and
adjacent circuit components.
Note that pin 25 is the NPN open collector output (active low). Keep pin 25 open-connection when not using.
4. CONTROL pin (pin 1)
The protective circuit response speed is adjusted by the pin 1 capacitor.
By adjusting the response speed of the protective circuit, abnormal sound generated when the protective circuit
operates at input of the large signal can be prevented.
When the capacitance value increases, abnormal sound is more difficult to be generated, but the response speed of the
protective circuit becomes lower. The capacitance value must be limited to maximum 0.01µF. The recommended
value is 4700pF.
Check the optimum value for each set.
As this is designed so that the protective circuit is activated when pin 1 has the GND potential, the protective circuit
becomes normally active when the capacitor is short-circuited.
5. AC GND pin (pin 16)
Be sure to use the pin 16 capacitor with the capacity the same as that of the input capacitor and connect it to PREGND
the same as that of the input capacitor.
6. Sound quality (low frequencies)
The frequency characteristics in low frequency range may be improved by varying the capacitance of input capacitor.
Note that this may cause influence on the shock noise, carry out confirmation with each set before varying the
capacitance value.
7. Impulse noise related systems
While the LA47202P does include an impulse noise prevention circuit, we recommend using the muting function
together with this circuit.
•
When the amplifier is ON, turn ON the muting function simultaneously with power ON. When the output DC
potential has stabilized, turn OFF the muting function.
•
When turning OFF the amplifier, first turn ON the muting function, then turn OFF power supply.
No.A0508-4/8
LA47202P
8. Oscillation stability
Pay due attention on the following points because parasitic oscillation may occur due to effects of the capacity load,
board layout, etc.
(1) Capacity load
When the capacitor is to be inserted between each output pin and GND so as to prevent electric mirror noise, select
the capacitance of maximum 1200pF. (Conditions : Our recommended board, RL = 4Ω)
(2) Board layout
•
Provide the VCC capacitor of 0.1µF in the position nearest to IC.
•
PREGND must be independently wired and connected to the GND point that is as stable as possible, such as the
minus pin of the 2200µF VCC capacitor.
In case of occurrence of parasitic oscillation, any one of following parts may be added as a countermeasure.
Note that the optimum capacitance must be checked for each set in the mounted state.
•
Series connection of CR (0.1µF and 2.2Ω) between BTL outputs
•
Series connection of CR (0.1µF and 2.2Ω) between each output pin and GND.
Package Dimensions
unit : mm (typ)
3236A
29.2
(22.8)
(8.5)
( 2.5)
4.5
70
Pd max -- Ta
Maximum power dissipation, Pd max -- W
25.6
60
(12.3)
(5.0)
(R1.7)
18.6 max
(14.4)
50
Infinite heat sink
θj-c=1°C/W
21.7
40
(11.0)
30
heat sink(θf=3.5°C/W)
θj-c+θf=4.5°C/W
0.4
1
(2.6)
(1.0)
0.52
25
3.5
14.5
20
4.0
4.2
10
2.0
2.0
No heat sink
θj-a=39°C/W
-20
0
20
40
60
80
100
120
140
160
0
-40
Ambient temperature, Ta --
°C
SANYO : HZIP25
No.A0508-5/8
stm32/stm8
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