LA4628 Datasheet, PDF (4/8 Pages) Sanyo Semicon Device – Two-Channel 20 W BTL Audio Power Amplifier

LA4628
Pin Voltages
VCC = 13.5V, with 5V applied to STBY through a 10kΩ resistor, RL = 4Ω, Rg = 0
Pin No.
1
2
3
4
5
Pin name
IN1
DC
PRE–GND
STBY
ON TIME
Pin voltage
1.55V
6.63V
0V
3.21V
2.32V
6
IN2
1.55V
7
POP
2.07V
Pin No.
Pin name
Pin voltage
8
+OUT2
6.6V
9
-OUT2
6.5V
10
PWR–GND
0V
11
+OUT1
6.5V
12
PWR–GND
0V
13
-OUT1
6.6V
14
VCC
13.5V
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 LA4628 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 13.5V 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 is the standby switch. A voltage of 2.5V
or higher must be applied through an external
resistor to turn the amplifier on.
• If a voltage of over 13.5V will be applied as the
standby mode switching voltage, use the following
formula to determine the value of R1 so that the
current entering at pin 4 remains under 500µA.
<applied voltage>−1.4
R1 =
−10kΩ
500μA
Pin 4 Internal Equivalent Circuit
500μA or lower
4
R1
10kΩ
Applied standby
voltage
About 1.4V
(2VBE)
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.
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