VCC max = ±49 V
VCC = ±32.5 V
RL = 8 ohm
PO = 40 W.
fL,fH = 20 to 50k Hz
Description of External Parts
| C3, C4 | Input filter capacitors
• A filter formed with R5 or R6 can be used to reduce noise at high frequencies. |
| C5, C6 | Input coupling capacitors
• Used to block DC current. When the reactance of the capacitor increases at low frequencies, the dependence of 1/f noise on signal source
resistance causes the output noise to worsen. It is better to decrease the reactance.
• To reduce the pop noise at the time of application of power, it is effective to increase C5, C6 that fix the time constant on the input side and
to decrease C9, C10 on the NF side. |
| C9, C10 | NF capacitors
• These capacitors fix the low cutoff frequency |
| C19 | Decoupling capacitor
• Used to eliminate the ripple components that mix into the input side from the power line (+VCC). |
| C15, C16 | Bootstrap capacitors
• When the capacitor value is decreased, the distortion is liable to be higher at low frequencies. |
| C17, C18 | Oscillation blocking capacitors
• Must be inserted as close to the IC power supply pins as possible so that the power supply impedance is decreased to operate the IC stably.
• Electrolytic capacitors are recommended for C17, C18. |
| C20 | Capacitor for ripple filter
• Capacitor for the TR12-used ripple filter in the IC system |
| C13 | Oscillation blocking capacitor
• A polyester film capacitor, being excellent in temperature characteristic, frequency characteristic, is recommended for C13. |
| R5, R6 | Resistors for input filter |
| R3, R4 | Input bias resistors
• Used to bias the input pin potential to zero. These resistors fix the input impedance practically. |
| R7, R9
(R8, R10) | These resistors fix voltage gain VG.
It is recommended to use R7 (R8) = 560 R9 (R10) = 56k for VG = 40dB.
• To adjust VG, it is desirable to change R7 (or R8).
• When R7 (or R8) is changed to adjust VG, R3 (=R4) =R9 (=R10) must be set to ensure VN balance. |
| R11, R20
(R12, R21) | Bootstrap resistors
• The quiescent current is set by these resistors 3.3k
+ 3.3k It is recommended to use this resistor value. |
| R15 | Resistor for ripple filter
• (Limiting resistor for predriver TR at the time of load short) |
| R14 | Used to ensure plus/minus balance at the time of clip. |
| R18, R19 | Resistor for ripple filter
• When muting TR13 is turned ON, current flows from ground to -VCC through TR 13. It is recommended to use 1k (1W) + 1k (1W) allowing for the power that may be dissipated on that occasion. |
| R24, R25 | Oscillation blocking resistors |
| R22, R23 | Oscillation blocking resistors |
| L1, L2 | Oscillation blocking coils |
POWER SUPPLY FOR STK4171V 40+40 W. AF PA CIRCUIT
PRINTED CIRCUIT PATTERN FOR STK4171V 40+40 W. AF PA CIRCUIT
