參數(shù)資料
型號: LT1994
廠商: Linear Technology Corporation
英文描述: 1.3GHz Low Noise, Low Distortion Differential ADC Driver for 140MHz IF
中文描述: 1.3GHz的低噪聲,低失真差分ADC驅(qū)動器為140MHz的中頻
文件頁數(shù): 10/16頁
文件大小: 232K
代理商: LT1994
LTC6401-20
10
640120f
APPLICATIONS INFORMATION
Circuit Operation
The LTC6401-20 is a low noise and low distortion fully
differential op amp/ADC driver with:
Operation from DC to 1.3GHz –3dB bandwidth
impedance
Fixed gain of 10V/V (20dB)
Differential input impedance 200
Ω
Differential output impedance 25
Ω
Differential impedance of output filter 100
Ω
The LTC6401-20 is composed of a fully differential amplifier
with on chip feedback and output common mode voltage
control circuitry. Differential gain and input impedance are
set by 100
Ω
/1000
Ω
resistors in the feedback network.
Small output resistors of 12.5
Ω
improve the circuit stability
over various load conditions. They also provide a possible
external filtering option, which is often desirable when the
load is an ADC.
Filter resistors of 50
Ω
are available for additional filtering.
Lowpass/bandpass filters are easily implemented with just
a couple of external components. Moreover, they offer
single-ended 50
Ω
matching in wideband applications and
no external resistor is needed.
The LTC6401-20 is very flexible in terms of I/O coupling.
It can be AC- or DC-coupled at the inputs, the outputs or
both. Due to the internal connection between input and
output, users are advised to keep input common mode
voltage between 1V and 1.6V for proper operation. If the
inputs are AC-coupled, the input common mode voltage
is automatically biased close to V
OCM
and thus no external
circuitry is needed for bias. The LTC6401-20 provides an
output common mode voltage set by V
OCM
, which allows
driving an ADC directly without external components such
as a transformer or AC coupling capacitors. The input
signal can be either single-ended or differential with only
minor differences in distortion performance.
Input Impedance and Matching
The differential input impedance of the LTC6401-20 is
200
Ω
. If a 200
Ω
source impedance is unavailable, then
the differential inputs may need to be terminated to a lower
value impedance, e.g. 50
Ω
, in order to provide an imped-
ance match to the source. Several choices are available.
One approach is to use a differential shunt resistor (Figure
1). Another approach is to employ a wideband transformer
(Figure 2). Both methods provide a wideband match. The
termination resistor or the transformer must be placed
close to the input pins in order to minimize the reflection
due to input mismatch. Alternatively, one could apply a
narrowband impedance match at the inputs of the LTC6401-
20 for frequency selection and/or noise reduction.
Referring to Figure 3, LTC6401-20 can be easily configured
for single-ended input and differential output without a
balun. The signal is fed to one of the inputs through a
matching network while the other input is connected to
the same matching network and a source resistor. Because
the return ratios of the two feedback paths are equal, the
Figure 1. Input Termination for Differential 50
Ω
Input Impedance
Using Shunt Resistor
Figure 2. Input Termination for Differential 50
Ω
Input Impedance
Using a 1:4 Balun
640120 F01
IN+
OUT–
IN–
OUT+
100
Ω
66.5
Ω
12.5
Ω
1000
Ω
LTC6401-20
100
Ω
25
Ω
25
Ω
V
IN
1000
Ω
12.5
Ω
50
Ω
50
Ω
13
14
15
16
7
5
6
8
+
+OUT
+OUTF
–OUTF
–OUT
+IN
+IN
–IN
–IN
1.7pF
640120 F02
IN+
OUT–
IN–
OUT+
100
Ω
12.5
Ω
1000
Ω
LTC6401-20
100
Ω
25
Ω
25
Ω
V
IN
1000
Ω
12.5
Ω
50
Ω
50
Ω
13
14
15
16
7
5
6
8
+
1:4
+OUT
+OUTF
–OUTF
–OUT
+IN
+IN
–IN
–IN
1.7pF
相關(guān)PDF資料
PDF描述
LTC6400-20 1.3GHz Low Noise, Low Distortion Differential ADC Driver for 140MHz IF
LTC6401-20 1.3GHz Low Noise, Low Distortion Differential ADC Driver for 140MHz IF
LTC6401CUD-20PBF 1.3GHz Low Noise, Low Distortion Differential ADC Driver for 140MHz IF
LTC6401CUD-20TRPBF 1.3GHz Low Noise, Low Distortion Differential ADC Driver for 140MHz IF
LTC6401IUD-20PBF 1.3GHz Low Noise, Low Distortion Differential ADC Driver for 140MHz IF
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
LT1994CDD 制造商:Linear Technology 功能描述:SC-Amps/High Speed, 70MHz Low Noise/Distortion Differential Amplifer
LT1994CDD#PBF 功能描述:IC DIFF AMP/DRIVER LN 8-DFN RoHS:是 類別:集成電路 (IC) >> Linear - Amplifiers - Instrumentation 系列:- 產(chǎn)品培訓(xùn)模塊:Differential Circuit Design Techniques for Communication Applications 標準包裝:1 系列:- 放大器類型:RF/IF 差分 電路數(shù):1 輸出類型:差分 轉(zhuǎn)換速率:9800 V/µs 增益帶寬積:- -3db帶寬:2.9GHz 電流 - 輸入偏壓:3µA 電壓 - 輸入偏移:- 電流 - 電源:40mA 電流 - 輸出 / 通道:- 電壓 - 電源,單路/雙路(±):3 V ~ 3.6 V 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:16-VQFN 裸露焊盤,CSP 供應(yīng)商設(shè)備封裝:16-LFCSP-VQ 包裝:剪切帶 (CT) 產(chǎn)品目錄頁面:551 (CN2011-ZH PDF) 其它名稱:ADL5561ACPZ-R7CT
LT1994CDD#PBF 制造商:Linear Technology 功能描述:Operational Amplifier (Op-Amp) IC 制造商:Linear Technology 功能描述:IC, DIFFERENTIAL AMP, 70MHZ, 65V/ uS DFN8
LT1994CDD#TR 制造商:Linear Technology 功能描述:DIFF-AMPLIFIER, 70MHZ, 65V/US, DFN-8, No. of Amplifiers:1, Input Offset Voltage: 制造商:Linear Technology 功能描述:DIFF-AMPLIFIER, 70MHZ, 65V/US, DFN-8, No. of Amplifiers:1, Input Offset Voltage:2mV, Bandwidth:70MHz, Amplifier Case Style:DFN, No. of Pins:8, Supply Voltage Range:2.375V to 12.6V, Slew Rate:65V/s, Supply Current:14.8mA, MSL:- , RoHS Compliant: No
LT1994CDD#TRPBF 功能描述:IC DIFF AMP/DRIVER LN 8-DFN RoHS:是 類別:集成電路 (IC) >> Linear - Amplifiers - Instrumentation 系列:- 標準包裝:50 系列:- 放大器類型:通用 電路數(shù):2 輸出類型:滿擺幅 轉(zhuǎn)換速率:1.8 V/µs 增益帶寬積:6.5MHz -3db帶寬:4.5MHz 電流 - 輸入偏壓:5nA 電壓 - 輸入偏移:100µV 電流 - 電源:65µA 電流 - 輸出 / 通道:35mA 電壓 - 電源,單路/雙路(±):1.8 V ~ 5.25 V,±0.9 V ~ 2.625 V 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:10-TFSOP,10-MSOP(0.118",3.00mm 寬) 供應(yīng)商設(shè)備封裝:10-MSOP 包裝:管件