STK433-090-E Sanyo, STK433-090-E Datasheet - Page 10

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

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2) Load short-circuit detection block
3) Latch-up circuit block
4) DC offset protection block
STK433-100 Series BTL Application
Since the voltage between point B and point C is less than 0.6V in normal operation mode (V BE < 0.6V) and TR1 (or
TR2) is not activated, the load short-circuit detection block does not operate.
When a load short-circuit occurs, however, the voltage between point B and point C becomes larger than 0.6V,
causing TR1 (or TR2) to turn on (V BE > 0.6V), and current I2 to flows.
TR3 is activated when I2 is supplied to the latch-up circuit.
When TR3 turns on and current I3 starts flowing, VST goes down to 0V (standby mode), protecting the power
amplifier.
Since TR3 and TR4 configure a thyristor, once TR3 is activated, the IC is held in the standby mode.
To release the standby mode and reactivate the power amplifier, it is necessary to set the standby control voltage (*2)
temporarily low (0V). Subsequently, when the standby control is returned to high, the power amplifier will become
active again.
(*4) The I3 value varies depending on the supply voltage. Determine the value of R2 using the formula below, so that
The DC offset protection circuit is activated when ±0.5V (typ) voltage is applied to either "OUT CH1" or "OUT
CH2," and the hybrid IC is shut down (standby mode).
To release the IC from the standby mode and reactivate the power amplifier, it is necessary to set the standby control
voltage temporarily low (0V).
Subsequently, when the standby control is returned to high (+5V, for example), the power amplifier will become
active again.
The protection level must be set using the 82kΩ resistor. Furthermore, the time constant must be determined using
22μ//22μ capacitors to prevent the amplifier from malfunctioning due to the audio signal.
100μF
/100V
-PRE
I1 is equal to or less than I3.
I1 ≤ I3 = V CC /R2
1
100Ω
/1W
-V CC
-V CC
4.7Ω/1W
2
100μF
/100V
0.1μF
+V CC
+V CC
3
3μH
0.22Ω
OUT
Ch1
4
56kΩ
3pF
0.1μF
4.7Ω
/1W
R L =8Ω
OUT
OUT
Ch1
STK433-100-E series
4.7Ω
5
0.22Ω
3μH
OUT
Ch2
6
56kΩ
100Ω/1W
3pF
OUT
Ch2
7
4.7Ω
33μF
+PRE
8
100μF
33μF
/100V
SUB GND
9
56kΩ
10
STK433-090-E
Ch1
11
IN
100pF
Ch1
12
NF
1.8kΩ
10μF
/10V
ST-BY
13
14
Ch2
NF
1.8kΩ
10μF
/10V
Ch2
15
IN
2.2μF
/50V
(*1) The voltage applied to the Stand-by pin (#13) must not
exceed the maximum rated value (VST max).
(*1) R1
1kΩ
Stand-by Control
GND
Ch1 IN
No. A1248-10/11