STK433-090-E Sanyo, STK433-090-E Datasheet - Page 9

• Manufacturer Part Number: STK433-090-E
• Description: 2-Channel Class AB Audio Power IC
• Manufacturer: Sanyo

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STK433-100 Series Application Explanation
The protection circuit application for the STK433-100sr consists of the following blocks (blocks (1) to (4)).
(1) Standby control circuit block
(2) Load short-circuit detection block
(3) Latch-up circuit block
(4) DC voltage protection block
1) Standby control circuit block
Concerning pin 13 reference voltage VST
(Reference example) STK433-100 series test circuit (when +5V is applied to Stand-by control.)
<1> Operation mode
<2> Standby mode
-PRE
1
Point.B
The switching transistor in the bias circuit turns on and places the amplifier into the operating mode when the
current flowing into pin 13 (IST) becomes 0.25mA or greater.
When the current flowing into pin 13 (IST) is stopped (=0mA), the switching transistor in the bias circuit turns
off, placing the amplifier into the standby mode.
(*1) The current limiting resistor (R1) must be used to ensure that the current flowing into the stand-by pin
(*2) The pop noise level when the power is turned on can be reduced by setting the time constant with a
(*3) Determines the time constant at which the capacitor (*3) is discharged in standby mode.
(2) Load short
-PRE
1
detection part
-V CC
2
STK433-100series
(pin 13) does not exceed its maximum rated value IST max.
capacitor in operating mode.
STK433-100 series
-V CC
2
+V CC
3
56kΩ
+V CC
3
Tr1
6.8kΩ
OUT
Ch1
4
OUT(+)
Point.C
Ch1
OUT Ch1
4
OUT
Ch1
5
OUT(-)
Point.B
Ch1
56kΩ
5
OUT
Ch2
6
OUT(+)
6.8kΩ
Tr2
Ch2
6
OUT
Ch2
OUT Ch2
7
OUT(-)
Ch2
7
+PRE
8
Point.C
+PRE
8
SUB
I2
9
SUB GND
GND
Stand-by Circuit
in Pre Driver IC
9
Stand-by Circuit
in Pre Driver IC
10
STK433-090-E
10
Ch1
IN
11
0.1μF 10kΩ
82kΩ
82kΩ
Ch1
11
ΔVBE
IN
Ch1
NF
ΔV BE
SW transistor
12
Tr4
22μF
22μF
Ch1
NF
ST-BY
12
100kΩ
1kΩ
22kΩ
ST-BY
13
56kΩ
13
-V CC
100
kΩ
Tr3
(*4) R2
Tr5
14
Ch2
NF
Ch2
14
NF
IST
15
Ch2
IN
Ch2
15
IN
(3) Latch-up
Tr6
circuit part
Sink current IST
I3
(4) DC offset
ex) Stand-by control voltage=+5V
IST=(VST-VBE*2)/R1
=(5-0.6*2)/13kΩ
≈0.3(mA)
(*1) R1
13kΩ
ex) 13kΩ
protection
(*1) R1
ΔVBE
Tr5
33μF
33μF
(*2)
33kΩ
1kΩ (*3)
1) Stand-by control circuit part
H: Operation mode (+5V)
L: Stand-by mode (0V)
33kΩ
1kΩ
2kΩ
2kΩ (*3)
1) Stand-by control
H: Operation mode (+5V)
L: Stand-by mode (0V)
VST
No. A1248-9/11
(*2)
ex) +5V