參數(shù)資料
型號(hào): LMV710M5
廠商: NATIONAL SEMICONDUCTOR CORP
元件分類: 運(yùn)算放大器
英文描述: Low Power, RRIO Operational Amplifiers with High Output Current Drive and Shutdown Option
中文描述: OP-AMP, 3200 uV OFFSET-MAX, 5 MHz BAND WIDTH, PDSO5
封裝: SOT-23, 5 PIN
文件頁(yè)數(shù): 14/19頁(yè)
文件大?。?/td> 708K
代理商: LMV710M5
Application Note
(Continued)
GSM POWER AMPLIFIER CONTROL LOOP
There are four critical sections in the GSM Power Amplifier
Control Loop. The class-C R
power amplifier provides am-
plification of the R
F
signal. A directional coupler couples
small amount of R
energy from the output of the R
P. A. to
an envelope detector diode. The detector diode senses the
signal level and rectifies it to a DC level to indicate the signal
strength at the antenna. An op-amp is used as an error
amplifier to process the diode voltage and ramping voltage.
This loop control the power amplifier gain via the op-amp
and forces the detector diode voltage and ramping voltage to
be equal. Power control is accomplished by changing the
ramping voltage.
The LMV710, LMV711 and LMV715 are well suited as an
error amplifier in this application. The LMV711 and LMV715
have an extra shutdown pin to switch the op-amp to shut-
down mode. In shutdown mode, the LMV711 and LMV715
consume very low current. The LMV711 provides a ground
voltage to the power amplifier control pin V
. Therefore, the
power amplifier can be turned off to save battery life. The
LMV715 output will be “tri-stated” when in shutdown.
10132506
FIGURE 9. Typical of GSM P.A. Control Loop
L
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相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
LMV710M5 制造商:Texas Instruments 功能描述:OP AMP BICMOS SMD SOT-23-5 710
LMV710M5/NOPB 功能描述:運(yùn)算放大器 - 運(yùn)放 LOW PWR, RRIO OP AMP W/ HI-OTPT CURR DRV RoHS:否 制造商:STMicroelectronics 通道數(shù)量:4 共模抑制比(最小值):63 dB 輸入補(bǔ)償電壓:1 mV 輸入偏流(最大值):10 pA 工作電源電壓:2.7 V to 5.5 V 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:QFN-16 轉(zhuǎn)換速度:0.89 V/us 關(guān)閉:No 輸出電流:55 mA 最大工作溫度:+ 125 C 封裝:Reel
LMV710M5X 功能描述:運(yùn)算放大器 - 運(yùn)放 RoHS:否 制造商:STMicroelectronics 通道數(shù)量:4 共模抑制比(最小值):63 dB 輸入補(bǔ)償電壓:1 mV 輸入偏流(最大值):10 pA 工作電源電壓:2.7 V to 5.5 V 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:QFN-16 轉(zhuǎn)換速度:0.89 V/us 關(guān)閉:No 輸出電流:55 mA 最大工作溫度:+ 125 C 封裝:Reel
LMV710M5X/NOPB 功能描述:運(yùn)算放大器 - 運(yùn)放 RoHS:否 制造商:STMicroelectronics 通道數(shù)量:4 共模抑制比(最小值):63 dB 輸入補(bǔ)償電壓:1 mV 輸入偏流(最大值):10 pA 工作電源電壓:2.7 V to 5.5 V 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:QFN-16 轉(zhuǎn)換速度:0.89 V/us 關(guān)閉:No 輸出電流:55 mA 最大工作溫度:+ 125 C 封裝:Reel
LMV711 制造商:TI 制造商全稱:Texas Instruments 功能描述:SINGLE LOW-POWER RRIO OPERATIONAL AMPLIFIERS WITH HIGH OUTPUT CURRENT DRIVE AND SHUTDOWN