Ordering number : EN6631A

Monolithic Linear IC

LA4625 2-channel 13.5W BTL Audio Power

Amplifier
Overview
The LA4625 is a 2-channel general-purpose BTL audio power amplifier provided in a miniature package. It was designed
for the best possible audio quality and features an extended low band roll-off frequency provided by a newly-developed NF
circuit that does not require an external capacitor. Furthermore, crosstalk, which can cause muddiness in the audio output,
has been significantly reduced by both circuit and wiring pattern improvements. Thus this amplifier can provide powerful
lows and clear highs.
Note that this device is pin compatible with the 20W×2-channel LA4628, and allows end products differentiated by their
power rating to share the same printed circuit board.

Features
• Total output : 13.5W+13.5W (at VCC = 12V, RL = 4Ω, THD = 10%)
• PMPO reference data : 115W×2 (VCC = 20V, RL = 4Ω)
• High-fidelity design (fL < 10Hz, fH = 130kHz)
• Extremely low impulse noise levels
• An arbitrary amplifier startup time can be set up with external components.
• Full complement of built-in protection circuits (includes circuits that protect against shorting to VCC, shorting to ground,
load shorting, overvoltages and excessive temperatures)

Specifications
Maximum Ratings at Ta = 25°C
Parameter Symbol Conditions Ratings Unit
Maximum supply voltage VCC max No signal 24 V
Maximum output current IO peak Per channel 3.5 A
Allowable power dissipation Pd max With an arbitrarily large heat sink 32.5 W
Operating temperature Topr -20 to +85 °C
Storage temperature Tstg -40 to +150 °C

Any and all SANYO Semiconductor Co.,Ltd. products described or contained herein are, with regard to
"standard application", intended for the use as general electronics equipment (home appliances, AV equipment,
communication device, office equipment, industrial equipment etc.). The products mentioned herein shall not be
intended for use for any "special application" (medical equipment whose purpose is to sustain life, aerospace
instrument, nuclear control device, burning appliances, transportation machine, traffic signal system, safety
equipment etc.) that shall require extremely high level of reliability and can directly threaten human lives in case
of failure or malfunction of the product or may cause harm to human bodies, nor shall they grant any guarantee
thereof. If you should intend to use our products for applications outside the standard applications of our
customer who is considering such use and/or outside the scope of our intended standard applications, please
consult with us prior to the intended use. If there is no consultation or inquiry before the intended use, our
customer shall be solely responsible for the use.
Specifications of any and all SANYO Semiconductor Co.,Ltd. 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.

O0808 MS JK/92900RM (OT) No.6631-1/8

 LA4625
Operating Conditions at Ta = 25°C
Parameter Symbol Conditions Ratings Unit
Recommended supply voltage VCC 12 V
Recommended load resistance range RL op 4 to 8 Ω
Allowable operating supply voltage VCC op 7.2 to 20 V
Note : With VCC, RL, and the output level in ranges such that the Pd max for the heat sink used is not exceeded.

Electrical Characteristics at Ta = 25°C, VCC = 12V, RL = 4Ω, f = 1kHz, Rg = 600Ω

Ratings
Parameter Symbol Conditions Unit
min typ max
Quiescent current ICCO Rg = 0 65 120 240 mA
Standby mode current drain Ist Standby mode (amplifier off), with no power 10 60 µA
supply capacitor.
Voltage gain VG VO = 0dBm 38 40 42 dB
Total harmonic distortion THD PO = 1W, Filter = FLAT 0.06 0.2 %
Output power PO1 THD = 10% 10 13.5 W
Output offset voltage VN offset Rg = 0 -300 +300 mV
Output noise voltage VNO Rg = 0, BPF = 20Hz to 20kHz 0.1 0.5 mV
Ripple rejection ratio SVRR Rg = 0, VR = 0dBm, fR = 100Hz 40 50 dB
Channel separation CHsep Rg = 10kΩ, VO = 0dBm 50 60 dB
Input resistance Ri 21 30 39 kΩ
Standby pin applied voltage VST Amplifier on 2.5 VCC V
(applied through an external 10kΩ resistor)

Package Dimensions
unit : mm (typ)
3113B Pd max -- Ta
35
Infinite heat sink AI heat sink Mounting
Allowable power dissipation, Pd max -- W

32.5
torque 39N • cm Flat
30
washer Silicone grease
applied
θf = 3˚C/W
25

20.83
θf = 4˚C/W
20
θjc = 2˚C/W
15 θf = 7˚C/W
13.9
10.4
θf = 10˚C/W
10

5 Νο Fin
3.1

0
-20 0 20 40 60 80 100 120 140 160
Ambient temperature, Ta -- ˚C

No.6631-2/8
 LA4625
Block Diagram
C2
100µF/16V VCC
+

2200µF
+
C5

25V
2 14

OUTPUT PIN TO VCC

RIPPLE SHORT PROTECTOR
FILTER

-OUT1 –
PREDRIVER POWER 13

0.1µF
C6**
C1

2.2Ω 2.2Ω
+
1 +
LOAD SHORT POWER R2 RL
IN 12
2.2µF – PROTECTOR GND1 4Ω
10V R3

0.1µF
C7**
PREDRIVER POWER 11
+OUT1
+

PRE GND OUTPUT PIN TO GND

3 BIAS OVER VOLTAGE / SHORT PROTECTOR
CIRCUIT SURGE PROTECTOR
**
(POLYESTER FILM
R1 VCC
CAPACITOR)
ON 10KΩ
4 STANDBY THERMAL
OFF SW SHUT DOWN OUTPUT PIN TO GND
SHORT PROTECTOR
Standby +5V
SW
-OUT2 –
PREDRIVER POWER 9

0.1µF
IN2 C8**
C4

2.2Ω 2.2Ω
+
6 + LOAD SHORT POWER R4 RL
2.2µF IN
PROTECTOR GND2
10 4Ω
– R5
10V

0.1µF
C9**
PREDRIVER POWER 8
+OUT2 +
OUTPUT PIN TO VCC
SHORT PROTECTOR

POP NOISE
PREVENTION
CIRCUIT

5 7
0.47µF
33µF

+ +
10V

10V

C3 C10

C3 C10
Sets the amplifier starting time Impulse noise reduction
(Approximately 0.6 seconds when 33µF) (Note : The device’s ability to withstand shorting
to VCC or shorting to ground when VCC is around
16V may be reduced as the value of this
capacitor is increased. We recommend 0.47µF.)

No.6631-3/8
 LA4625
Pin Voltages
VCC = 12V, with 5V applied to STBY through a 10kΩ resistor, RL = 4Ω, Rg = 0
Pin No. 1 2 3 4 5 6 7
Pin name IN1 DC PRE-GND STBY ON TIME IN2 POP
Pin voltage 1.46V 5.18V 0V 3.21V 2.26V 1.46V 2.05V

Pin No. 8 9 10 11 12 13 14
Pin name +OUT2 −OUT2 PWR-GN +OUT1 PWR-GN −OUT1 VCC
Pin voltage 5.21V 5.21V 0V 5.21V 0V 5.21V 12V

External Components
C1 and C4: Input capacitors. A value of 2.2µF is recommended. Determine the polarity based on the DC potential of
the circuit connected directly to the LA4625 front end. Note that the low band response can be adjusted by
varying fL with the capacitors C1 and C4.
C2 : Decoupling capacitor (ripple filter)
C3 : Sets the amplifier starting time, which will be approximately 0.6 seconds for a value of 33µF. The starting
time is proportional to the value of this capacitor, and can be set to any desired value.
C5 : Power-supply capacitor
C6, C7, C8, and C9 :
Oscillation prevention capacitors. Use polyester film capacitors (Mylar capacitors) with excellent
characteristics. (Note that the series resistors R2, R3, R4, and R5 are used in conjunction with these
capacitors to achieve stable amplifier operation.) A value of 0.1µF is recommended.
C10 : Impulse noise reduction capacitor. A value of 0.47µF is recommended. Caution is required when selecting
the value for this capacitor, since increasing its value influences the operation of the circuits that protect
against shorting the amplifier output pins to VCC or to ground when higher VCC voltages (approximately
16V or higher) are used.
R1 : Standby switch current limiting resistor. A value of 10kΩ is recommended when a voltage in the range 2.5 to
12V will be applied as the standby switching voltage. Note that this resistor is not optional: it must be included.

IC Internal Characteristics and Notes

1. Standby function Pin 4 Internal Equivalent Circuit
• Pin 4 is the standby switch. A voltage of 2.5V or 500µA or lower
higher must be applied through an external resistor to 10kΩ
turn the amplifier on. 4
• If a voltage of over 12V will be applied as the R1

standby mode switching voltage, use the following

formula to determine the value of R1 so that the Applied standby About 1.4V
voltage (2VBE)
current entering at pin 4 remains under 500µA.

<applied voltage> − 1.4

R1 = − 10kΩ
500µA

2. Muting function
• Pin 5 connects the capacitor that determines the starting time to prevent impulse noise. It can also be used to mute
the amplifier output by shorting pin 5 to ground. When this function is used, the recovery time depends on C3.

3. Impulse noise improvements

• While the LA4625 achieves a low level of impulse noise, if even further reductions in impulse noise at power
on/off (and when switching into or out of standby mode) a 0.47µF capacitor may be inserted between pin 7 and the
PRE GND pin (pin 3). (Pin 7 is the output amplifier bias pin. Since the ability to withstand shorting the output pins
to VCC or ground is reduced for supply voltages over 16V if the pin 7 capacitance is large, we recommend a value
of 0.47µF or lower for this capacitor.)

No.6631-4/8
 LA4625
4. Protection circuits
• Due to the system structure of the protection circuit for shorts to VCC or ground, if there is a DC resistance
between the amplifier output pins and ground, the protection circuit may operate when power is first applied and
the amplifier may fail to turn on. The basic design approach we recommend is not to adopt any designs in which
there is a DC resistance between the amplifier outputs and ground.

• The LA4625 includes a built-in thermal protection circuit to prevent the IC from being damaged or destroyed if
abnormally high temperatures occur. This thermal protection circuit gradually reduces the output if the IC
junction temperature (Tj) reaches the range 170 to 180°C due to inadequate heat sinking or other problem. If the
temperature falls, the amplifier will restart automatically.

• The LA4625 also includes other protection circuits. Use of these circuits also requires care during end product
design and testing.

5. Other notes
• The LA4625 is a BTL power amplifier. When testing this device, the ground systems for the test equipment
connected to IC inputs, and that for the test equipment connected to IC outputs, must be isolated. Do not use a
common ground.

Printed Circuit Pattern

(copper foil side)

No.6631-5/8
 LA4625
PO -- VCC PO -- VIN
60 100
f = 1kHz 7 VCC = 12V
5
Rg = 600Ω RL = 4Ω
3
50
RL = 4Ω 2 f = 1kHz
10
Output power, PO -- W

Output power, PO -- W
7
40 5
3
2
0%
=3
30 1.0
7
THD 5
3
20 10% 2
0.1
7
10 5
3
2
0 0.01
6 7 8 9 10 11 12 13 14 15 16 17 18 1.0 2 3 5 7 10 2 3 5 7 100 2 3 5 7 1k
Supply voltage, VCC -- V Input voltage, VIN -- mVrms
PO -- f f Response
24 2
VCC = 12V
RL = 4Ω
20 Rg = 600Ω 0
Output power, PO -- W

16 -2

Response -- dB
THD = 10%
12 THD = 3% -4

THD = 1%
8 -6

VCC = 12V
4 -8 RL = 4Ω
Rg = 600Ω
VO = 0dBm at f = 1kHz
0 -10
10 2 3 5 7 100 2 3 5 7 1k 2 3 5 7 10k 2 3 5 7100k 10 2 3 5 7 100 2 3 5 7 1k 2 3 5 7 10k 2 3 5 7100k
Frequency, f -- Hz Frequency, f -- Hz
THD -- PO THD -- f
10 10
7 VCC = 12V 7 VCC = 12V
5 RL = 4Ω 5 RL = 4Ω
Total harmonic distortion, THD -- %
Total harmonic distortion, THD -- %

3 Rg = 600Ω 3 PO = 1W
2 2

1.0 1.0
7 7
5 5
3 3
10kHz
2 2

0.1 0.1
7 100kHz 7
5 5
1kHz
3 3
2 2

0.01 0.01
0.1 2 3 5 7 1.0 2 3 5 7 10 2 3 5 7 100 10 2 3 5 7 100 2 3 5 7 1k 2 3 5 7 10k 2 3 5 7100k
Output power, PO -- W Frequency, f -- Hz
CHsep -- f VNO -- Rg
0 1.0
VCC = 12V VCC = 12V
7
10 RL = 4Ω RL = 4Ω
Output noise voltage, VNO -- mVrms

Rg = 10kΩ 5
Channel separation, CHsep -- dB

20 VO = 0dBm
3
30 2

40
0.1
50 CH1→2 7

60 5
CH2→1
70 3

2
80

90 0.01
10 2 3 5 7100 2 3 5 7 1k 2 3 5 7 10k 2 3 5 7100k 100 2 3 5 7 1k 2 3 5 7 10k 2 3 5 7 100k
Frequency, f -- Hz Signal source resistance, Rg -- Ω

No.6631-6/8
 LA4625
SVRR -- VCC SVRR -- VCCR
0 0
Rg = 0 VCC = 12V
fR = 100Hz RL = 4Ω
VCCR = 0dBm

Ripple rejection ratio, SVRR -- dB

Ripple rejection ratio, SVRR -- dB

-20
-20

-40 100Hz OUT1

OUT1 100Hz OUT2
-40

-60 OUT2

-60
-80
3kHz OUT1
3kHz OUT2
-80
-100

SVRR = 20log VO
VCCR
-120 -100
4 6 7 8 10 12 14 16 18 20 22 0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0
Supply voltage, VCC -- V Power supply ripple, VCCR -- Vrms
SVRR -- fR ICCO -- VCC
0 180
VCC = 12V RL = Open
RL = 4Ω 160 Rg = 0
Rg = 0
Ripple rejection ratio, SVRR -- dB

Quiescent current, ICCO -- mA

-20 VCCR = 0dBm 140

120
-40
100

OUT1 80
-60
OUT2 60

-80 40

20

-100 0
10 2 3 5 7 100 2 3 5 7 1k 2 3 5 7 10k 2 3 5 7100k 0 4 8 12 16 20 24 28 32 36
Ripple frequency, fR -- Hz Supply voltage, VCC -- V
VN -- VCC Pd, ICC -- PO
12 100 10
RL = 4Ω RL = 4Ω
Rg = 0 7 Rg = 600Ω 7

10 5 f = 1kHz 5

Power dissipation, ICC -- A

I CC
Power dissipation, Pd -- W

3 3
8 2 2
5V
=1
VN -- V

V CC
6 10
= 12V 1.0
7
VCC 7
5 5
4

3 3
2 2 2

0 1.0 0.1
0 5 10 15 20 25 30 35 0.1 2 3 5 7 1.0 2 3 5 7 10 2 3 5 7 100
Supply voltage, VCC -- V Output power, PO -- W/CH
Amp ON time
1.0
VCC = 12V
VST = 5V
0.8
Amp ON time -- s

0.6

0.4

0.2

0
1.0 2 3 5 7 10 2 3 5 7 100
C3 -- µF

No.6631-7/8
 LA4625

SANYO Semiconductor Co.,Ltd. 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 Co.,Ltd.
products described or contained herein.
SANYO Semiconductor Co.,Ltd. strives to supply high-quality high-reliability products, however, any and all
semiconductor products fail or malfunction with some probability. It is possible that these probabilistic failures or
malfunction could give rise to accidents or events that could endanger human lives, trouble that could give rise
to smoke or fire, or accidents 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.
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controlled under any of applicable local export control laws and regulations, such products may require the
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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 Semiconductor Co.,Ltd. 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.
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above.

This catalog provides information as of October, 2008. Specifications and information herein are subject to
change without notice.

PS No.6631-8/8