LT6411_15 datasheet(10/16 Pages) LINER

Part #	LT6411

Description	650MHz Differential ADC Driver/Dual Selectable Gain Amplifi er

Download	16 Pages

Scroll/Zoom	100%

Manufacturer	LINER [Linear Technology]

Direct Link	http://www.linear.com

Logo

10 / 16 page

LT6411

10

6411f

APPLICATIONS INFORMATION

Input Considerations

The LT6411 input voltage range is from VEE + 1V to

VCC – 1V. Therefore, on split supplies the LT6411 input

range is always as large as or larger than the output swing.

On a single positive supply with a gain of +2 and IN– con-

nected to ground, however, the input range limit of +1V

limits the linear output low swing to 2V (1V multiplied by

the internal gain of 2).

The inputs can be driven beyond the point at which the

output clips so long as input currents are limited to

±10mA. Continuing to drive the input beyond the output

limit can result in increased current drive and slightly

increased swing, but will also increase supply current

and may result in delays in transient response at larger

levels of overdrive.

DC Biasing Differential Ampliﬁer Applications

The inputs of the LT6411 must be DC biased within the

input common mode voltage range, typically VEE + 1V to

VCC – 1V. If the inputs are AC coupled or DC biased be-

yond the input voltage range of a driven A-to-D converter,

DC biasing or level shifting will be required. In the basic

circuit conﬁgurations shown in Figure 1, the DC input

common mode voltage and the differential input signal

are both multiplied by the ampliﬁer gain. In the gain of

+2 conﬁguration, the DC common mode voltage gain can

be set to unity by adding a capacitor at the IN– pins as

shown in Figure 2.

If the inputs are AC coupled or the LT6411 is preceded

by a highpass ﬁlter, the input common mode voltage can

be set by resistor dividers as shown in Figure 3. Adding

the blocking capacitor to the gain setting resistors sets

the input and output DC common mode voltages equal.

When using the LT6411 to drive an A-to-D converter, the

DC common mode voltage level will affect the harmonic

distortion of the combined ampliﬁer/ADC system. Figure 4

shows the measured distortion of an LTC2249 ADC when

driven by the LT6411 at different common mode voltage

levels with the inputs conﬁgured as shown in Figure 3.

Adjusting the DC bias voltage can optimize the design for

the lowest possible distortion.

If the input signals are within the input voltage range

and output swing of the LT6411, but outside the input

range of an ADC or other circuit the LT6411 is driving,

+

–

+V

LT6411

IN+

IN–

CLARGE

VDC

OUT+

OUT–

VDC

6411 F02

Figure 2. LT6411 Conﬁgured with a Differential Gain of 2

and Unity DC Common Mode Gain

+

–

+V

LT6411

IN+

IN–

OV

OUT+

OUT–

VDC

CLARGE

V+

R1

R2

V+

R1

R2

VDC

6411 F03

Figure 3. Using Resistor Dividers to Set the

Input Common Mode Voltage When AC Coupling

VCM (V)

1.6

–70

–65

HD3

HD2

IM3

–60

2.4

6411 F04

–75

–80

–90

1.8

2.0

2.2

1.7

2.5

1.9

2.1

2.3

–85

–50

–55

VCC = 5V, VEE = 0V

AV= 2

TA = 25°C

Figure 4. Harmonic and Intermodulation Distortion of the

LT6411 Driving an LTC2249 Versus DC Common Mode

Voltage. Harmonic Distortion Measured with a –1dBFS Signal

at 30.2MHz. Intermodulation Distortion Measured with Two

–7dBFS Tones at 30.2MHz and 29.2MHz

Similar Part No. - LT6411_15

Manufacturer	Part #	Datasheet	Description
Linear Technology	LT6411CUD	361Kb / 16P	650MHz Differential ADC Driver/Dual Selectable Gain Amplifi er
Linear Technology	LT6411IUD	361Kb / 16P	650MHz Differential ADC Driver/Dual Selectable Gain Amplifi er

More results

Similar Description - LT6411_15

Manufacturer	Part #	Datasheet	Description
Linear Technology	LT6411	361Kb / 16P	650MHz Differential ADC Driver/Dual Selectable Gain Amplifi er
	LT1991	279Kb / 28P	Precision, 100關A Gain Selectable Amplifi er
	LT6402-12	230Kb / 16P	300MHz Low Distortion, Low Noise Differential Amplifi er/ ADC Driver (AV = 12dB)
	LT6402-6	236Kb / 16P	300MHz Low Distortion, Low Noise Differential Amplifi er/ ADC Driver (AV = 6dB)
	LT1993-10	739Kb / 16P	700MHz Low Distortion, Low Noise Differential Amplifi er/ADC Driver (AV = 10V/V)
API Technologies Corp	BXMF1043	324Kb / 2P	Automatic Gain Controlled Amplifi er
Linear Technology	LT1993-2	671Kb / 20P	800MHz Low Distortion, Low Noise Differential Amplifi er/ADC Driver (AV = 2V/V)
Analog Devices	ADA4950-1	675Kb / 28P	Low Power, Selectable Gain Differential ADC Driver, G = 1, 2, 3 REV. 0
Linear Technology	LT1993-4	720Kb / 16P	900MHz Low Distortion, Low Noise Differential Amplifi er/ADC Driver (AV = 4V/V)
Analog Devices	ADA4950-1	600Kb / 26P	Low Power, Selectable Gain Differential ADC Driver, G = 1, 2, 3

More results

LT6411 Datasheet(PDF) 10 Page - Linear Technology

LT6411 Datasheet(HTML) 10 Page - Linear Technology

Similar Part No. - LT6411_15

Similar Description - LT6411_15

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Datasheet Download

Link URL