參數(shù)資料
型號(hào): LA4555
廠商: Sanyo Electric Co.,Ltd.
英文描述: 2-Channel AF Power Amplifier for Radio, Tape Recorder Use
中文描述: 2通道自動(dòng)對(duì)焦功率放大器收音機(jī),磁帶錄音機(jī)的使用
文件頁(yè)數(shù): 4/10頁(yè)
文件大?。?/td> 345K
代理商: LA4555
LA4555
No.1697–4/10
Continued from preceding page.
C7 (C8) : Output capacitor. The low cutoff frequency is determined by the following formula.
1
2
π
C7RL
fL : Low cutoff frequency
RL : Load resistance
To make the low frequency response in the bridge amplifier mode identical with that in the stereo mode, the
capacitor value must be doubled.
Decoupling capacitor. Used for the ripple filter. Since the rejection effect is saturated at a certain capacitor
value, it is meaningless to increase the capacitor value more than needed. This capacitor, being also used for
the time constant of the muting circuit, affects the starting time.
Power source capacitor.
C9 :
C10 :
Application Circuits
Voltage gain adjust
· Stereo mode
The voltage gain is determined by on-chip resistor R1 (R2) and external feedback resistor Rf as follows :
Any voltage gain can be obtained by external
resistor Rf.
· Bridge amplifier 1 mode
Since point A is at the same potential as Vi and point B is a virtual GND point,
Assuming R2=R4=50
, R1=R3=20k
and Rf1=Rf2, the voltage gain is obtained by :
R1
Rf1+R2
· Bridge amplifier 2 mode
The CH1 is a noninverting amplifer and the CH2 is an inverting amplifier. The total voltage gain, being apparently
higher than that of the CH1 by 6dB, is approximately calculated by the following formula.
VG=20log R2/R1+6 (dB)
To reduce the voltage gain, Rf is connected and the following formula is used.
VG=20log R2/Rf+R1+6 (dB)
fL=
VG=20 log R1
Rf1+R2
Vo1
R1
R2+R4+Rf1+Rf2
R2+R4+Rf1+Rf2
VG=20 log [dB]
Vo2
–R3
VG=20 log Vo
Vi
R1+R3
R2+R4+Rf1+Rf2
Vo = Vo1 – Vo2 = R2+R4+Rf1+Rf2
R1+R3
相關(guān)PDF資料
PDF描述
LA4557 2-Channel AF Power Amp for Radio, Tape Recorder Use
LA4558 2-Channel AF Power Amp
LA4571MB Low-Voltage Headphone Amplifier for Stereo Audio
LA4575 2-Channel Pre + Power 3V Headphone Amp
LA4575M 2-Channel Pre + Power 3V Headphone Amp
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
LA4557 制造商:Panasonic Industrial Company 功能描述:IC
LA4558 制造商:Panasonic Industrial Company 功能描述:IC
LA4560M 制造商:未知廠家 制造商全稱:未知廠家 功能描述:Analog IC
LA4570 制造商:未知廠家 制造商全稱:未知廠家 功能描述:Analog IC
LA4570M 制造商:未知廠家 制造商全稱:未知廠家 功能描述:Analog IC