- 您现在的位置：买卖IC网 > PDF目录358884 > LMV1032UP-06 (NATIONAL SEMICONDUCTOR CORP) Amplifiers for 3 Wire Analog Electret Microphones PDF资料下载
参数资料
| 型号： | LMV1032UP-06 |
| 厂商： | NATIONAL SEMICONDUCTOR CORP |
| 元件分类： | 音频／视频放大 |
| 英文描述： | Amplifiers for 3 Wire Analog Electret Microphones |
| 中文描述： | 1 CHANNEL, AUDIO AMPLIFIER, PBGA4 |
| 封装： | ROHS COMPLIANT, MO-211CA, MICRO, SMD-4 |
| 文件页数： | 8/11页 |
| 文件大小： | 406K |
| 代理商： | LMV1032UP-06 |
Application Section
LOW CURRENT
The LMV1032 has low supply current for a longer battery life.
The low supply current makes this amplifier suitable for
microphone applications which need to be always on.
BUILT IN GAIN
The LMV1032 is offered in space saving small micro SMD
package in order to fit in the metal can of a microphone. The
LMV1032 is placed on the PCB inside the microphone.
The bottom side of the PCB has the pins that connect the
supply voltage to the amplifier and make the output avail-
able. The input of the amplifier is connected inside the metal
can via the PCB to the microphone.
A-WEIGHTED FILTER
The human ear has a frequency range from 20 Hz to about
20 kHz. Within this range the sensitivity of the human ear is
not equal for each frequency. To approach the hearing re-
sponse weighting filters are introduced. One of those filters
is the A-weighted filter.
The A-weighted filter is usually used in signal to noise ratio
measurements, where sound is compared to device noise. It
improves the correlation of the measured data to the signal
to noise ratio perceived by the human ear.
MEASURING NOISE AND SNR
The overall noise of the LMV1032 is measured within the
frequency band from 10 Hz to 22 kHz using an A-weighted
filter. The input of the LMV1032 is connected to ground with
a 5 pF capacitor.
Signal to noise ratio (SNR) is measured with a 1 kHz input
signal of 18 mV
PP
using an A-weighted filter. This represents
a sound pressure level of 94 dB SPL. No input capacitor is
connected.
SOUND PRESSURE LEVEL
The volume of sound applied to a microphone is usually
stated as a pressure level referred to the threshold of hear-
ing of the human ear. The sound pressure level (SPL) in
decibels is defined by:
Sound pressure level (dB) = 20 log P
m
/P
O
Where,
P
m
is the measured sound pressure
P
O
is the threshold of hearing (20μPa)
In order to be able to calculate the resulting output voltage of
the microphone for a given SPL, the sound pressure in dB
SPL needs to be converted to the absolute sound pressure
in dBPa. This is the sound pressure level in decibels referred
to 1 Pascal (Pa).
20084202
FIGURE 1. Built-in Gain
20084209
FIGURE 2. A-Weighted Filter
20084210
FIGURE 3. Noise Measurement Setup
L
www.national.com
8
相关PDF资料 |
PDF描述 |
|---|---|
| LMV1032UPX-25 | Amplifiers for 3 Wire Analog Electret Microphones |
| LMV1032UPX-15 | Amplifiers for 3 Wire Analog Electret Microphones |
| LMV1032UPX-06 | Amplifiers for 3 Wire Analog Electret Microphones |
| LMV1032UP-25 | Amplifiers for 3 Wire Analog Electret Microphones |
| LMV1032UP-15 | Amplifiers for 3 Wire Analog Electret Microphones |
相关代理商/技术参数 |
参数描述 |
|---|---|
| LMV1032UP-06/NOPB | 功能描述:音频放大器 RoHS:否 制造商:STMicroelectronics 产品:General Purpose Audio Amplifiers 输出类型:Digital 输出功率: THD + 噪声: 工作电源电压:3.3 V 电源电流: 最大功率耗散: 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:TQFP-64 封装:Reel |
| LMV1032UP-15 | 制造商:Texas Instruments 功能描述:AMP MICROPHONE 15DB GAIN SMD 1014 |
| LMV1032UP-15/NOPB | 功能描述:音频放大器 RoHS:否 制造商:STMicroelectronics 产品:General Purpose Audio Amplifiers 输出类型:Digital 输出功率: THD + 噪声: 工作电源电压:3.3 V 电源电流: 最大功率耗散: 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:TQFP-64 封装:Reel |
| LMV1032UP-25 | 制造商:Texas Instruments 功能描述:MICROPHONE AMP 25DB GAIN SMD 1032 |
| LMV1032UP-25/NOPB | 功能描述:音频放大器 RoHS:否 制造商:STMicroelectronics 产品:General Purpose Audio Amplifiers 输出类型:Digital 输出功率: THD + 噪声: 工作电源电压:3.3 V 电源电流: 最大功率耗散: 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:TQFP-64 封装:Reel |
发布紧急采购，3分钟左右您将得到回复。