CA RA R1 33k R2 5k TAPE HEAD" />
參數(shù)資料
型號(hào)： OP27GS
廠(chǎng)商： Analog Devices Inc
文件頁(yè)數(shù)： 9/20頁(yè)
文件大?。?/td> 0K
描述： IC OPAMP GP 8MHZ LN PREC 8SOIC
標(biāo)準(zhǔn)包裝： 98
放大器類(lèi)型： 通用
電路數(shù)： 1
轉(zhuǎn)換速率： 2.8 V/µs
增益帶寬積： 8MHz
電流 - 輸入偏壓： 15nA
電壓 - 輸入偏移： 30µV
電壓 - 電源，單路/雙路(±)： ±4 V ~ 18 V
工作溫度： -40°C ~ 85°C
安裝類(lèi)型： 表面貼裝
封裝/外殼： 8-SOIC（0.154"，3.90mm 寬）
供應(yīng)商設(shè)備封裝： 8-SO
包裝： 管件
OP27
Rev. F | Page 17 of 20
CA
RA
R1
33k
R2
5k
TAPE
HEAD
0.47F
0.01F
10
15k
T1 = 3180s
T2 = 50s
OP27
+
–
00
31
7-
0
42
Figure 42. Tape Head Preamplifier
While the tape equalization requirement has a flat high
frequency gain above 3 kHz (T2 = 50 μs), the amplifier need
not be stabilized for unity gain. The decompensated OP37
provides a greater bandwidth and slew rate. For many applica-
tions, the idealized time constants shown can require trimming
of R1 and R2 to optimize frequency response for nonideal tape
head performance and other factors (see the References
section).
The network values of the configuration yield a 50 dB gain at
1 kHz, and the dc gain is greater than 70 dB. Thus, the worst-
case output offset is just over 500 mV. A single 0.47 μF output
capacitor can block this level without affecting the dynamic
range.
The tape head can be coupled directly to the amplifier input,
because the worst-case bias current of 80 nA with a 400 mH,
100 μ inch head (such as the PRB2H7K) is not troublesome.
Amplifier bias-current transients that can magnetize a head
present one potential tape head problem. The OP27 and OP37
are free of bias current transients upon power-up or power-
down. It is always advantageous to control the speed of power
supply rise and fall to eliminate transients.
In addition, the dc resistance of the head should be carefully
controlled and preferably below 1 kΩ. For this configuration,
the bias current induced offset voltage can be greater than the
100 pV maximum offset if the head resistance is not sufficiently
controlled.
A simple, but effective, fixed gain transformerless microphone
preamp (Figure 43) amplifies differential signals from low
impedance microphones by 50 dB and has an input impedance
of 2 kΩ. Because of the high working gain of the circuit, an
OP37 helps to preserve bandwidth, which is 110 kHz. As the
OP37 is a decompensated device (minimum stable gain of 5), a
dummy resistor, Rp, may be necessary if the microphone is to be
unplugged. Otherwise, the 100% feedback from the open input
can cause the amplifier to oscillate.
Common-mode input noise rejection will depend upon the
match of the bridge-resistor ratios. Either close tolerance (0.1%)
types should be used, or R4 should be trimmed for best CMRR.
All resistors should be metal film types for best stability and low
noise.
Noise performance of this circuit is limited more by the Input
Resistors R1 and R2 than by the op amp, as R1 and R2 each
generate a 4 nV/√Hz noise, while the op amp generates a
3.2 nV/√Hz noise. The rms sum of these predominant noise
sources is about 6 nV/√Hz, equivalent to 0.9 μV in a 20 kHz
noise bandwidth, or nearly 61 dB below a 1 mV input signal.
Measurements confirm this predicted performance.
LOW IMPEDANCE
MICROPHONE INPUT
(Z = 50 TO 200)
C1
5mF
R1
1k
R3
316k
R6
100
R4
316k
R2
1k
RP
30k
OUTPUT
R3
R1
R4
R2
=
OP27/
OP37
+
–
R7
10k
00
31
7-
0
43
Figure 43. Fixed Gain Transformerless Microphone Preamplifier
For applications demanding appreciably lower noise, a high
quality microphone transformer coupled preamplifier (Figure
44) incorporates the internally compensated OP27. T1 is a JE-
115K-E 150 Ω/15 kΩ transformer that provides an optimum
source resistance for the OP27 device. The circuit has an overall
gain of 40 dB, the product of the transformer’s voltage setup and
the op amp’s voltage gain.
JENSEN TRANSFORMERS
A1
OP27
R3
100
R1
121
R2
1100
C2
1800pF
OUTPUT
150
SOURCE
T11
T1 – JENSEN JE – 115K – E
1
3
6
2
00
31
7-
0
44
Figure 44. High Quality Microphone Transformer Coupled Preamplifier
Gain can be trimmed to other levels, if desired, by adjusting R2
or R1. Because of the low offset voltage of the OP27, the output
offset of this circuit is very low, 1.7 mV or less, for a 40 dB gain.
The typical output blocking capacitor can be eliminated in such
cases, but it is desirable for higher gains to eliminate switching
transients.
OP27
–18V
+18V
8
7
6
4
3
2
00317-045
Figure 45. Burn-In Circuit
相關(guān)PDF資料
PDF描述
OP282GS IC OPAMP JFET 4MHZ DUAL LP 8SOIC
OP285GSZ-REEL IC OPAMP GP 9MHZ DUAL PREC 8SOIC
OP291GSZ-REEL7 IC OPAMP GP R-R 3MHZ DUAL 8SOIC
OP293FSZ-REEL IC OPAMP GP 35KHZ DUAL 8SOIC
OP295GS-REEL IC OPAMP GP R-R 85KHZ DUAL 8SOIC
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
OP-27GS 制造商:AD 制造商全稱(chēng):Analog Devices 功能描述:LOW NOISE, PRECISION OPERATIONAL AMPLIFIER
OP27GS+ 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
OP27GS+T 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
OP27GS8 功能描述:IC OPAMP PREC HI SPEED LN 8SOIC RoHS:否 類(lèi)別:集成電路 (IC) >> Linear - Amplifiers - Instrumentation 系列:- 標(biāo)準(zhǔn)包裝:100 系列:- 放大器類(lèi)型:通用 電路數(shù):1 輸出類(lèi)型:- 轉(zhuǎn)換速率:0.2 V/µs 增益帶寬積:- -3db帶寬:- 電流 - 輸入偏壓:100pA 電壓 - 輸入偏移:30µV 電流 - 電源:380µA 電流 - 輸出 / 通道:- 電壓 - 電源，單路/雙路(±):±2 V ~ 18 V 工作溫度:0°C ~ 70°C 安裝類(lèi)型:表面貼裝 封裝/外殼:8-SOIC（0.154"，3.90mm 寬） 供應(yīng)商設(shè)備封裝:8-SO 包裝:管件
OP27GS8#PBF 功能描述:IC OPAMP PREC HI SPEED LN 8SOIC RoHS:是 類(lèi)別:集成電路 (IC) >> Linear - Amplifiers - Instrumentation 系列:- 標(biāo)準(zhǔn)包裝:100 系列:- 放大器類(lèi)型:通用 電路數(shù):1 輸出類(lèi)型:- 轉(zhuǎn)換速率:0.2 V/µs 增益帶寬積:- -3db帶寬:- 電流 - 輸入偏壓:100pA 電壓 - 輸入偏移:30µV 電流 - 電源:380µA 電流 - 輸出 / 通道:- 電壓 - 電源，單路/雙路(±):±2 V ~ 18 V 工作溫度:0°C ~ 70°C 安裝類(lèi)型:表面貼裝 封裝/外殼:8-SOIC（0.154"，3.90mm 寬） 供應(yīng)商設(shè)備封裝:8-SO 包裝:管件
發(fā)布緊急采購(gòu)，3分鐘左右您將得到回復(fù)。

采購(gòu)需求

(若只采購(gòu)一條型號(hào)，填寫(xiě)一行即可)

發(fā)布成功！您可以繼續(xù)發(fā)布采購(gòu)。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

發(fā)布成功！您可以繼續(xù)發(fā)布采購(gòu)。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

*型號(hào) *數(shù)量 廠(chǎng)商 批號(hào) 封裝
添加更多采購(gòu)

我的聯(lián)系方式

*
*
*