- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄5436 > AD8657ACPZ-RL (Analog Devices Inc)IC OPAMP R-R 18V 200KHZ 8LFCSP PDF資料下載
參數(shù)資料
| 型號： | AD8657ACPZ-RL |
| 廠商： | Analog Devices Inc |
| 文件頁數(shù)： | 13/24頁 |
| 文件大?。?/td> | 0K |
| 描述： | IC OPAMP R-R 18V 200KHZ 8LFCSP |
| 標(biāo)準(zhǔn)包裝： | 5,000 |
| 放大器類型： | 通用 |
| 電路數(shù)： | 2 |
| 輸出類型： | 滿擺幅 |
| 轉(zhuǎn)換速率： | 0.07 V/µs |
| 增益帶寬積： | 200kHz |
| 電流 - 輸入偏壓： | 5pA |
| 電壓 - 輸入偏移： | 350µV |
| 電流 - 電源： | 18µA |
| 電流 - 輸出 / 通道： | 12mA |
| 電壓 - 電源，單路/雙路(±)： | 2.7 V ~ 18 V，±1.35 V ~ 9 V |
| 工作溫度： | -40°C ~ 125°C |
| 安裝類型： | 表面貼裝 |
| 封裝/外殼： | 8-WFDFN 裸露焊盤，CSP |
| 供應(yīng)商設(shè)備封裝： | 8-LFCSP-WD（3x3） |
| 包裝： | 帶卷 (TR) |
AD8657
Rev. A | Page 20 of 24
EMI REJECTION RATIO
Circuit performance is often adversely affected by high frequency
electromagnetic interference (EMI). In the event where signal
strength is low and transmission lines are long, an op amp must
accurately amplify the input signals. However, all op amp pins—
the noninverting input, inverting input, positive supply, negative
supply, and output pins—are susceptible to EMI signals. These
high frequency signals are coupled into an op amp by various
means such as conduction, near field radiation, or far field radi-
ation. For instance, wires and PCB traces can act as antennas and
pick up high frequency EMI signals.
Precision op amps, such as the AD8657, do not amplify EMI or
RF signals because of their relatively low bandwidth. However,
due to the nonlinearities of the input devices, op amps can rectify
these out-of-band signals. When these high frequency signals
are rectified, they appear as a dc offset at the output.
To describe the ability of the AD8657 to perform as intended in
the presence of an electromagnetic energy, the electromagnetic
interference rejection ratio (EMIRR) of the noninverting pin is
section. A mathematical method of measuring EMIRR is
defined as follows:
EMIRR = 20 log (VIN_PEAK/ΔVOS)
20
40
60
80
100
120
140
10M
100M
1G
10G
E
M
IRR
(
d
B)
FREQUENCY (Hz)
VIN = 100mVPEAK
VSY = 2.7V TO 18V
08804-
071
Figure 72. EMIRR vs. Frequency
4 mA TO 20 mA PROCESS CONTROL CURRENT
LOOP TRANSMITTER
The 2-wire current transmitters are often used in distributed
control systems and process control applications to transmit
analog signals between sensors and process controllers. Figure 73
shows a 4 mA to 20 mA current loop transmitter.
The transmitter powers directly from the control loop power
supply, and the current in the loop carries signal from 4 mA to
20 mA. Thus, 4 mA establishes the baseline current budget within
which the circuit must operate. Using the AD8657 is an excellent
choice due to its low supply current of 33 μA per amplifier over
temperature and supply voltage. The current transmitter controls
the current flowing in the loop, where a zero-scale input signal
is represented by 4 mA of current and a full-scale input signal
is represented by 20 mA. The transmitter also floats from the
control loop power supply, VDD, while signal ground is in the
receiver. The loop current is measured at the load resistor, RL,
at the receiver side.
With a zero-scale input, a current of VREF/RNULL flows through
R. This creates a current flowing through the sense resistor,
details):
ISENSE, MIN = (VREF × R)/(RNULL × RSENSE)
With a full-scale input voltage, current flowing through R is
increased by the full-scale change in VIN/RSPAN. This creates an
increase in the current flowing through the sense resistor.
ISENSE, DELTA = (Full-Scale Change in VIN × R)/(RSPAN × RSENSE)
Therefore
ISENSE, MAX = ISENSE, MIN + ISENSE, DELTA
When R >> RSENSE, the current through the load resistor at the
receiver side is almost equivalent to ISENSE.
Figure 73 is designed for a full-scale input voltage of 5 V. At 0 V
of input, loop current is 3.5 mA, and at a full scale of 5 V, the
loop current is 21 mA. This allows software calibration to fine
tune the current loop to the 4 mA to 20 mA range.
The AD8657 and ADR125 both consume only 160 A quiescent
current, making 3.34 mA current available to power additional
signal conditioning circuitry or to power a bridge circuit.
RL
100
VDD
18V
C2
10F
C3
0.1F
C1
390pF
C4
0.1F
R4
3.3k
Q1
D1
4mA
TO
20mA
R3
1.2k
RNULL
1M
1%
VREF
RSPAN
200k
1%
VIN
0V TO 5V
R1
68k
1%
R2
2k
1%
NOTES
1. R1 + R2 = R.
1/2
AD8657
C5
10F
RSENSE
100
1%
08804-
060
VOUT
GND
ADR125
VIN
Figure 73. 4 mA to 20 mA Current Loop Transmitter
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| TSW-116-06-S-D | CONN HEADER 32POS .100" DL GOLD |
| CRCW12064R99FKEA | RES 4.99 OHM 1/4W 1% 1206 SMD |
| TSW-117-06-S-D | CONN HEADER 34POS .100" DL GOLD |
| LT1722CS5#TRPBF | IC OPAMP PREC 200MHZ TSOT-23-5 |
| SC-4 | FUSE 4A 600V T-LAG CLASS G |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| AD8657ARMZ | 功能描述:IC OP AMP RRIO 200KHZ 8-MSOP RoHS:是 類別:集成電路 (IC) >> Linear - Amplifiers - Instrumentation 系列:- 標(biāo)準(zhǔn)包裝:1 系列:- 放大器類型:通用 電路數(shù):4 輸出類型:滿擺幅 轉(zhuǎn)換速率:0.028 V/µs 增益帶寬積:105kHz -3db帶寬:- 電流 - 輸入偏壓:3nA 電壓 - 輸入偏移:100µV 電流 - 電源:3.3µA 電流 - 輸出 / 通道:12mA 電壓 - 電源，單路/雙路(±):2.7 V ~ 12 V，±1.35 V ~ 6 V 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:14-TSSOP（0.173"，4.40mm 寬） 供應(yīng)商設(shè)備封裝:14-TSSOP 包裝:剪切帶 (CT) 其它名稱:OP481GRUZ-REELCT |
| AD8657ARMZ_PROMO | 制造商:Analog Devices 功能描述:IC OP AMP RRIO 200KHZ MSOP |
| AD8657ARMZ-R7 | 功能描述:IC OP AMP RRIO 200KHZ 8MSOP RoHS:是 類別:集成電路 (IC) >> Linear - Amplifiers - Instrumentation 系列:- 標(biāo)準(zhǔn)包裝:2,500 系列:- 放大器類型:通用 電路數(shù):1 輸出類型:滿擺幅 轉(zhuǎn)換速率:0.11 V/µs 增益帶寬積:350kHz -3db帶寬:- 電流 - 輸入偏壓:4nA 電壓 - 輸入偏移:20µV 電流 - 電源:260µA 電流 - 輸出 / 通道:20mA 電壓 - 電源，單路/雙路(±):2.7 V ~ 36 V，±1.35 V ~ 18 V 工作溫度:-40°C ~ 85°C 安裝類型: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:帶卷 (TR) |
| AD8657ARMZ-RL | 功能描述:IC OP AMP RRIO 200KHZ 8MSOP RoHS:是 類別:集成電路 (IC) >> Linear - Amplifiers - Instrumentation 系列:- 標(biāo)準(zhǔn)包裝:2,500 系列:- 放大器類型:通用 電路數(shù):1 輸出類型:滿擺幅 轉(zhuǎn)換速率:0.11 V/µs 增益帶寬積:350kHz -3db帶寬:- 電流 - 輸入偏壓:4nA 電壓 - 輸入偏移:20µV 電流 - 電源:260µA 電流 - 輸出 / 通道:20mA 電壓 - 電源，單路/雙路(±):2.7 V ~ 36 V，±1.35 V ~ 18 V 工作溫度:-40°C ~ 85°C 安裝類型: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:帶卷 (TR) |
| AD8659ACPZ-R7 | 功能描述:IC OPAMP RRIO 18V CMOS 16LFCSP RoHS:是 類別:集成電路 (IC) >> Linear - Amplifiers - Instrumentation 系列:- 標(biāo)準(zhǔn)包裝:1,000 系列:- 放大器類型:電壓反饋 電路數(shù):4 輸出類型:滿擺幅 轉(zhuǎn)換速率:33 V/µs 增益帶寬積:20MHz -3db帶寬:30MHz 電流 - 輸入偏壓:2nA 電壓 - 輸入偏移:3000µV 電流 - 電源:2.5mA 電流 - 輸出 / 通道:30mA 電壓 - 電源，單路/雙路(±):4.5 V ~ 16.5 V，±2.25 V ~ 8.25 V 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:14-SOIC（0.154"，3.90mm 寬） 供應(yīng)商設(shè)備封裝:14-SOIC 包裝:帶卷 (TR) |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。