參數(shù)資料
型號: LM4753T
廠商: NATIONAL SEMICONDUCTOR CORP
元件分類: 音頻/視頻放大
英文描述: 11.8 W, 2 CHANNEL, AUDIO AMPLIFIER, PZFM15
封裝: TO-220, 15 PIN
文件頁數(shù): 16/16頁
文件大小: 511K
代理商: LM4753T
Application Information (Continued)
to ground for play mode, transistor Q1 is quickly cut off and
diode D1 is forward biased. When D1 is forward biased, ca-
pacitor C8 is quickly discharged to ground, bringing the
standby pin voltage to 0V. When C8 is discharged, diode D2
becomes reverse biased allowing capacitor C9 to discharge
to ground through R5. Diode D2 was clamping the voltage
on C9 to the same voltage as C8. Because R5 is 10 times
R4 it takes longer for the mute function to be disabled. While
the mute voltage is decreasing, the biasing of the amplifier is
charging up, since the standby function has already been
disabled. While the mute pin voltage is decreasing the vol-
ume pin voltage is slowly increasing through the charge-up
capacitor C7. Charging of the volume pin is from the 5V
through the volume control pot, R6 and C7. Notice that the
time constant of the volume pin charging is greater than the
mute pin discharging. As shown in
Figure 6, the volume con-
trol function finally ramps up the input signal, allowing music
to be amplified at the output.
Please notice that with this circuit the standby switch will
override the mute switch as required in the IC’s functional
truth table in
Table 1.
Also note once again that most systems typically utilize a mi-
croprocessor or COP microcontroller to interface with the
logic control functions of the LM4753. When a clean logic
signal is used, as from a microcontroller, RC lowpass filtering
is not required for the mute and standby functions.
DS100043-29
FIGURE 5. Turn-On/Off External Circuitry
www.national.com
9
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參數(shù)描述
LM4755 制造商:NSC 制造商全稱:National Semiconductor 功能描述:Stereo 11W Audio Power Amplifier with Mute
LM4755_02 制造商:NSC 制造商全稱:National Semiconductor 功能描述:Stereo 11W Audio Power Amplifier with Mute
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LM4755T/NOPB 功能描述:IC AMP AUDIO PWR 11W AB TO220-9 RoHS:是 類別:集成電路 (IC) >> 線性 - 音頻放大器 系列:- 產(chǎn)品培訓(xùn)模塊:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 標(biāo)準(zhǔn)包裝:2,500 系列:DirectDrive® 類型:H 類 輸出類型:耳機,2-通道(立體聲) 在某負(fù)載時最大輸出功率 x 通道數(shù)量:35mW x 2 @ 16 歐姆 電源電壓:1.62 V ~ 1.98 V 特點:I²C,麥克風(fēng),靜音,短路保護,音量控制 安裝類型:表面貼裝 供應(yīng)商設(shè)備封裝:25-WLP(2.09x2.09) 封裝/外殼:25-WFBGA,WLCSP 包裝:帶卷 (TR)
LM4755T/NOPB 制造商:Texas Instruments 功能描述:Audio Power Amplifier IC