自在自线亚洲а∨天堂在线-中文字幕一区视频播放-扒开双腿猛进入喷水高潮叫声-欧美日本亚洲一区二区-老熟妇高潮偷拍一区二区-国产精品高清一区二区不卡-午夜色福利视频一区二区三区-亚洲国产成人精品福利在线观看-亚洲欧美成人一区二区在线电影

ADI公司的AD8331/AD8332/AD8334是單/雙/四路超低噪音可變?cè)鲆娣糯笃鳎╒GA），每路包含了超低噪音預(yù)放大器(LNA)，48 dB增益的X-AMP®可變?cè)鲆娣糯笃鳎╒GA），以及可選擇增益的輸出放大器，因此最適合用于超聲波系統(tǒng)。本文介紹了AD8334的主要性能，方框圖，信號(hào)流程方框圖以及評(píng)估工具AD8334-bbbb的主要性能和電路圖。

Ultralow Noise VGAs with Preamplifier and Programmable RIN AD8331/AD8332/AD8334
The AD8331/AD8332/AD8334 are single-, dual-, and quad-channel ultralow noise, linear-in-dB, variable gain amplifiers (VGAs). Optimized for ultrasound systems, they are usable as a low noise variable gain element at frequencies up to 120 MHz.

Included in each channel are an ultralow noise preamplifier (LNA), an X-AMP® VGA with 48 dB of gain range, and a selectable gain postamplifier with adjustable output limiting. The LNA gain is 19 dB with a single-ended bbbbb and differential outputs. Using a single resistor, the LNA bbbbb impedance can be adjusted to match a signal source without compromising noise perbbbbance.

The 48 dB gain range of the VGA makes these devices suitable for a variety of applications. Excellent bandwidth unibbbbity is maintained across the entire range. The gain control interface provides precise linear-in-dB scaling of 50 dB/V for control voltages between 40 mV and 1 V. Factory trim ensures excellent part-to-part and channel-to-channel gain matching.

Differential signal paths result in superb second- and third-order distortion perbbbbance and low crosstalk.

The VGA’s low output-referred noise is advantageous in driving high speed differential ADCs. The gain of the postamplifier can be pin selected to 3.5 dB or 15.5 dB to optimize gain range and output noise for 12-bit or 10-bit converter applications. The output can be limited to a user-selected clamping level, preventing bbbbb overload to a subsequent ADC. An external resistor adjusts the clamping level.
The operating temperature range is −40°C to +85°C. The AD8331 is available in a 20-lead QSOP package, the AD8332 is available in 28-lead TSSOP and 32-lead LFCSP packages, and the AD8334 is available in a 64-lead LFCSP package.

主要特性：
Ultralow noise preamplifier
Voltage noise = 0.74 nV/√Hz
Current noise = 2.5 pA/√Hz
3 dB bandwidth
AD8331: 120 MHz
AD8332, AD8334: 100 MHz
Low power
AD8331: 125 mW/channel
AD8332, AD8334: 145 mW/channel
Wide gain range with programmable postamp
−4.5 dB to +43.5 dB
+7.5 dB to +55.5 dB
Low output-referred noise: 48 nV/√Hz typical
Active bbbbb impedance matching
Optimized for 10-bit/12-bit ADCs
Selectable output clamping level
Single 5 V supply operation
AD8332 and AD8334 available in lead frame chip scale package

主要應(yīng)用：
Ultrasound and sonar time-gain controls
High perbbbbance AGC systems
I/Q signal processing
High speed, dual ADC drivers



圖1。 AD8334 功能方框圖



圖2。 AD8334 信號(hào)流程方框圖

AD8334評(píng)估工具AD8334-bbbb
GENERAL DEbbbbbbION
The AD8334-bbbb is a platbbbb for the test and bbbbuation of the AD8334 variable gain amplifier (VGA). The board is shipped assembled and tested, and users only need to connect the signal and VGAIN sources and a single 5 V power supply. Figure 1 is a photograph of the board.
AD8334-bbbb主要特性：
Factory tested
Provisions for direct measurement
Optional differential-to-single-ended output
Provision for LNA output measurement
Selectable high or low gain
Provision for bbbbb calibration
Provision for clamping resistors
Single-supply operation
應(yīng)用：
Test gain interface circuitry
bbbbuate clamping characteristics
bbbbuate effects of dynamic drive signals
TGC bbbbuate system characteristics
Medical ultrasound systems
Industrial ultrasound systems
PC layout guidance
bbbbuate perbbbbance with real-world signals



圖3。AD8334-bbbb外形圖