- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄30753 > LM4841LQ/NOPB (NATIONAL SEMICONDUCTOR CORP) 2 CHANNEL(S), VOLUME CONTROL CIRCUIT, QCC28 PDF資料下載
參數(shù)資料
| 型號(hào)： | LM4841LQ/NOPB |
| 廠商： | NATIONAL SEMICONDUCTOR CORP |
| 元件分類： | 音頻控制 |
| 英文描述： | 2 CHANNEL(S), VOLUME CONTROL CIRCUIT, QCC28 |
| 封裝： | LLP-28 |
| 文件頁數(shù)： | 10/31頁 |
| 文件大?。?/td> | 1138K |
| 代理商： | LM4841LQ/NOPB |
第1頁第2頁第3頁第4頁第5頁第6頁第7頁第8頁第9頁當(dāng)前第10頁第11頁第12頁第13頁第14頁第15頁第16頁第17頁第18頁第19頁第20頁第21頁第22頁第23頁第24頁第25頁第26頁第27頁第28頁第29頁第30頁第31頁
Application Information (Continued)
BEEP DETECT FUNCTION
Computers and notebooks produce a system “beep“ signal
that drives a small speaker. The speaker’s auditory output
signifies that the system requires user attention or input. To
accommodate this system alert signal, the LM4841’s beep
input pin is a mono input that accepts the beep signal.
Internal level detection circuitry at this input monitors the
beep signal’s magnitude. When a signal level greater than
V
DD/2 is detected on the BEEP IN pin, the bridge output
amplifiers are enabled. The beep signal is amplified and
applied to the load connected to the output amplifiers. A valid
beep signal will be applied to the load even when MUTE is
active. Use the input resistors connected between the BEEP
IN pin and the stereo input pins to accommodate different
beep signal amplitudes. These resistors are shown as
200k
devices in Figure 2. Use higher value resistors to
reduce the gain applied to the beep signal. The resistors
must be used to pass the beep signal to the stereo inputs.
The BEEP IN pin is used only to detect the beep signal’s
magnitude: it does not pass the signal to the output amplifi-
ers. The LM4841’s shutdown mode must be deactivated
before a system alert signal is applied to BEEP IN pin.
MICRO-POWER SHUTDOWN
The voltage applied to the SHUTDOWN pin controls the
LM4841’s shutdown function. Activate micro-power shut-
down by applying ground (logic low) to the SHUTDOWN pin.
When activated, the LM4841’s micro-power shutdown fea-
ture turns off the amplifier’s bias circuitry, reducing the sup-
ply current. On the demo board, the micro-power shutdown
feature is controlled by a single pole switch that connects the
shutdown pin to either V
DD, for normal operation, or directly
to ground to enable shutdown. In a system with a micropro-
cessor or a microcontroller, use a digital output to apply the
control voltage to the SHUTDOWN pin.
MODE FUNCTION
The LM4841’s MODE function has 2 states controlled by the
voltage applied to the MODE pin. In Mode 0 (mode pin at
GND), the HP Sense has no effect on the gain setting (only
the Gain Select Input Controls either internal or external
gain). In Mode 1 (mode pin tied high), the HP Sense and
Gain Select both can toggle between Internal and External
Gain. See ’Truth Table for Logic Inputs’ on page 5.
MUTE FUNCTION
The LM4841 mutes the amplifier and DOCK outputs when
V
DD is applied to the MUTE pin. Even while muted, the
LM4841 will amplify a system alert (beep) signal whose
magnitude satisfies the BEEP DETECT circuitry. Applying
0V to the MUTE pin returns the LM4841 to normal, unmuted
operation. Prevent unanticipated mute behavior by connect-
ing the MUTE pin to V
DD or ground. Do not let the mute pin
float.
20028087
FIGURE 5. Headphone Sensing Circuit (MT & MH Packages)
LM4841
www.national.com
18
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| LM4842MHX/NOPB | 2 CHANNEL(S), TONE CONTROL CIRCUIT, PDSO28 |
| LM4842MTX/NOPB | 2 CHANNEL(S), TONE CONTROL CIRCUIT, PDSO28 |
| LM4843MH/NOPB | 2 CHANNEL(S), VOLUME CONTROL CIRCUIT, PDSO20 |
| LM4843MHX/NOPB | 2 CHANNEL(S), VOLUME CONTROL CIRCUIT, PDSO20 |
| LM4850MM/NOPB | 0.3 W, 2 CHANNEL, AUDIO AMPLIFIER, PDSO10 |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| LM4841MH | 制造商:NSC 制造商全稱:National Semiconductor 功能描述:Stereo 2W Amplifiers with DC Volume Control, Transient Free Outputs, and Cap-less Headphone Drive |
| LM4841MH/NOPB | 功能描述:IC AMP AUDIO PWR 2.2W AB 28TSSOP RoHS:是 類別:集成電路 (IC) >> 線性 - 音頻放大器 系列:Boomer® 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(jī)，2-通道（立體聲） 在某負(fù)載時(shí)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(diǎn):I²C，麥克風(fēng)，靜音，短路保護(hù)，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) |
| LM4841MT | 制造商:NSC 制造商全稱:National Semiconductor 功能描述:Stereo 2W Amplifiers with DC Volume Control, Transient Free Outputs, and Cap-less Headphone Drive |
| LM4841MT/NOPB | 功能描述:IC AMP AUDIO PWR 2.2W AB 28TSSOP RoHS:是 類別:集成電路 (IC) >> 線性 - 音頻放大器 系列:Boomer® 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(jī)，2-通道（立體聲） 在某負(fù)載時(shí)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(diǎn):I²C，麥克風(fēng)，靜音，短路保護(hù)，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) |
| LM4842 | 制造商:NSC 制造商全稱:National Semiconductor 功能描述:Stereo 2W Amplifiers with DC Volume Control Transient Free Outputs, and Cap-less Headphone Drive |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。