STK400-050 Sanyo Semiconductor Corporation, STK400-050 Datasheet - Page 4

• Manufacturer Part Number: STK400-050
• Description: af Power Amplifier (30W + 30W +30W)
• Manufacturer: Sanyo Semiconductor Corporation

Description of External Circuits
C1, 11, 21
C2, 12, 22
C3, 13, 23
C5, 15, 25
C6, 7
C8, 9, 28, 29
R1, 11, 21
R2, 12, 22
R3, 13, 23
R4, 14, 24
R5, 15, 25
R6, 16, 26
R8, 9, 28, 29
L1, 2, 3
For input coupling capacitor. Used for current blocking. When capacitor reactance with low
frequency is increased, the reactance value should be reduced in order to reduce the output
noise from the signal resistance dependent 1/f noise. In response to the popping noise which
occurs when the system power is turned on, C1 and C11 which determine the decay time
constant on the input side are increased while C3, C13 and C23 on the NF side are decreased.
For input filter capacitor. Permits high-region noise reduction by utilizing filter constructed with
R1, R11 and R21.
For NF capacitor. This capacitor determines the decline of the cut-off frequency and is
calculated according to the following equation.
f
For the purpose of achieving voltage gains prior to reduction, it is best that C3, C13 and C23 are
large. However, because the shock noise which occurs when the system power is turned on
tends to increase, values larger than those absolutely necessary should be avoided.
For oscillation prevention capacitor. A Mylar capacitor with temperature and frequency features
is recommended.
For oscillation prevention capacitor. To ensure safe IC functioning, the capacitor should be
installed as close as possible to the IC power pin to reduce power impedance. An electrolytic
capacitor is good.
For decoupling capacitor. Reduces shock noise during power up using decay time constant
circuits with R8, R9, R28 and R29 and eliminates components such as ripples crossing over into
the input side from the power line.
For input filter applied resistor.
For input bias resistor. The input pin is biased to zero potential. Input impedance is mostly
decided with this resistance value.
For resistors to determine voltage gain (VG). We recommend a VG = 40 dB using R3, R13, R23
= 560Ω and R4, R14 and R24 = 56Ω. VG adjustments are best performed using R3, R13 and
R23. When using R4, R14 and R24 for such purposes, R4, R14 and R24 should be set to equal
R2, R12 and R22 in order to establish a stable VN balance.
For oscillation prevention resistor.
For oscillation prevention resistor. This resistor’s electrical output resides in the signal frequency
and is calculated according to the following formula.
P R6 (16, 26) =
f = output signal frequency upper limit
For ripple filter applied resistor. PO max, ripple rejection and power-up shock noise are modified
according to this value. Set the electrical output of these resistors while keeping in mind the flow
of peak current during recharging to C8, C9, C28 and C29 which function as pre-drive TR control
resistors during load shorts.
For oscillation prevention coil. Compensates
and ensures stable oscillation.
L
=
2π X C3 (13, 23,) X R3 (13, 23)
(
1
1/2π fC5 (15, 25) + R6 (16, 26)
V
CC
max/√2
STK400-050
phase dislocation caused by load capacitors
)
2
X R6 (16, 26)
No. 4340-4/9