- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄385485 > LM4805LQ (NATIONAL SEMICONDUCTOR CORP) 3V, 1W Boosted Boomer PDF資料下載
參數(shù)資料
| 型號： | LM4805LQ |
| 廠商： | NATIONAL SEMICONDUCTOR CORP |
| 元件分類： | 音頻／視頻放大 |
| 英文描述： | 3V, 1W Boosted Boomer |
| 中文描述： | 1.2 W, 1 CHANNEL, AUDIO AMPLIFIER, QCC28 |
| 封裝： | LLP-28 |
| 文件頁數(shù)： | 11/18頁 |
| 文件大?。?/td> | 1063K |
| 代理商： | LM4805LQ |
Typical Performance Characteristics
(Continued)
Maximum Duty Cycle
vs Temperature - ”X”
R
DS
(ON)
vs Temperature
20126245
20126247
R
(ON)
vs V
DD
20126248
Application Information
BRIDGE CONFIGURATION EXPLANATION
The Audio Amplifier portion of the LM4805 has two internal
amplifiers allowing different amplifier configurations. The first
amplifier’s gain is externally configurable, whereas the sec-
ond amplifier is internally fixed in a unity-gain, inverting
configuration. The closed-loop gain of the first amplifier is set
by selecting the ratio of Rf to Ri while the second amplifier’s
gain is fixed by the two internal 20k
resistors. Figure 1
shows that the output of amplifier one serves as the input to
amplifier two. This results in both amplifiers producing sig-
nals identical in magnitude, but out of phase by 180. Con-
sequently, the differential gain for the Audio Amplifier is
A
VD
= 2 *(Rf/Ri)
By driving the load differentially through outputs VO1 and
VO2, an amplifier configuration commonly referred to as
“bridged mode” is established. Bridged mode operation is
different from the classic single-ended amplifier configura-
tion where one side of the load is connected to ground.
A bridge amplifier design has a few distinct advantages over
the single-ended configuration. It provides differential drive
to the load, thus doubling the output swing for a specified
supply voltage. Four times the output power is possible as
compared to a single-ended amplifier under the same con-
ditions. This increase in attainable output power assumes
that the amplifier is not current limited or clipped. In order to
choose an amplifier’s closed-loop gain without causing ex-
cessive clipping, please refer to the
Audio Power Amplifier
Design
section.
The bridge configuration also creates a second advantage
over single-ended amplifiers. Since the differential outputs,
VO1 and VO2, are biased at half-supply, no net DC voltage
exists across the load. This eliminates the need for an output
coupling capacitor which is required in a single supply,
single-ended amplifier configuration. Without an output cou-
pling capacitor, the half-supply bias across the load would
result in both increased internal IC power dissipation and
also possible loudspeaker damage.
AMPLIFIER POWER DISSIPATION
Power dissipation is a major concern when designing a
successful amplifier, whether the amplifier is bridged or
single-ended. A direct consequence of the increased power
delivered to the load by a bridge amplifier is an increase in
internal power dissipation. Since the amplifier portion of the
LM4805 has two operational amplifiers, the maximum inter-
L
www.national.com
11
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| LM4808 | Dual 105 mW Headphone Amplifier |
| LM4808M | Dual 105 mW Headphone Amplifier |
| LM4808MM | Dual 105 mW Headphone Amplifier |
| LM4831VF | Multimedia Computer Audio Chip |
| LM4831 | Multimedia Computer Audio Chip |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| LM4805LQ/NOPB | 功能描述:音頻放大器 RoHS:否 制造商:STMicroelectronics 產(chǎn)品:General Purpose Audio Amplifiers 輸出類型:Digital 輸出功率: THD + 噪聲: 工作電源電壓:3.3 V 電源電流: 最大功率耗散: 最大工作溫度: 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:TQFP-64 封裝:Reel |
| LM4805LQX | 功能描述:音頻放大器 RoHS:否 制造商:STMicroelectronics 產(chǎn)品:General Purpose Audio Amplifiers 輸出類型:Digital 輸出功率: THD + 噪聲: 工作電源電壓:3.3 V 電源電流: 最大功率耗散: 最大工作溫度: 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:TQFP-64 封裝:Reel |
| LM4805LQX/NOPB | 功能描述:音頻放大器 RoHS:否 制造商:STMicroelectronics 產(chǎn)品:General Purpose Audio Amplifiers 輸出類型:Digital 輸出功率: THD + 噪聲: 工作電源電壓:3.3 V 電源電流: 最大功率耗散: 最大工作溫度: 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:TQFP-64 封裝:Reel |
| LM4806 | 制造商:未知廠家 制造商全稱:未知廠家 功能描述:Dual 105mW Headphone Amplifier with Active-Low Shutdown Mode |
| LM4808 | 制造商:未知廠家 制造商全稱:未知廠家 功能描述: |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。