stk433-290-e Sanyo Semiconductor Corporation, stk433-290-e Datasheet - Page 10

• Manufacturer Part Number: stk433-290-e
• Description: Thick-film Hybrid 3-channel Class Audio Power 3-channel Class Audio Power
• Manufacturer: Sanyo Semiconductor Corporation

-PRE
1
[STK433-300 series Stand-By Control Using Example]
Characteristic
• It can largely improve a pop noise to occur in power supply ON/OFF by using recommended Stand-By Control
• Because It can perform Stand-By Control by regulating limit resistance to the voltage such as used microcomputers, a
(ex) STK433-300series test circuit. When impressed by Stand-by control control [+5V].
Operation Explanation
(1) Concerning pin 13 reference voltage VST
Application.
set design is easy.
<1> Operation mode
<2> Standby mode
-V CC
STK433-300 series
2
The SW transistor of bias circuit is turned on at VST≥2.5V, and the amplifier becomes operation mode.
ex) VST=2.5V
VST=(*2)×IST+0.6V→2.5V=4.7kΩ×IST+0.6V, IST≈0.40mA
The SW transistor of Pre-driver IC is turned off at VST≤0.6V (typ0V), and the amplifier becomes Stand-By
Mode.
ex) VST=0.6V
VST=(*2)×IST+0.6V→0.6V=4.7kΩ×IST+0.6V, IST≈0mA
(*3) It can improve a pop noise at power up time by giving a time constant of the condenser during operation.
(*4) Please decide a time constant to discharge the condenser during standby.
+V CC
3
OUT
Ch1
4
OUT
Ch1
5
OUT
Ch2
6
OUT
Ch2
7
+PRE
8
SUB GND
9
Concerning pin 13 reference
voltage VST
10
in PreDriver IC
Bias Circuit
ΔVBE
11
Ch1
IN
Ch1
STK433-290-E
NF
12
ST-
BY
13
Ch2
14
NF
4.7kΩ(*2)
15
Ch2
IN
Sink current IST
16
Ch3
IN
2.7kΩ(*1)
17
Ch3
NF
OUT
18
Ch3
OUT
ΔVBE
19
Ch3
ex) Stand-By control voltage=+5V
VST=(5V-VBE×2)×4.7kΩ/((*1)+4.7kΩ)+VBE
=(5V-0.6V×2)×4.7kΩ/(4.7kΩ+2.7kΩ)+0.6V
≈3.0(V)
33kΩ
33μF
(*3)
1kΩ
Stand-by Control
H: Operation Mode (+5V)
L: Stand-by Mode (0V)
2kΩ
(*4)
No. A1630-10/13