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LTC6417_15 Datasheet, PDF (1/32 Pages) Linear Technology – 1.6GHz Low Noise High Linearity Differential Buffer/16-Bit ADC Driver with Fast Clamp | |||
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LTC6417
Features
n 1.6GHz â3dB Small Signal Bandwidth
n Low Distortion Driving 50⦠Load, 2.4VP-P Out
â100dBc/â69dBc HD2/HD3 at 140MHz
â80dBc IM3 and 46dBm OIP3 at 140MHz
â100dBc/â66dBc HD2/HD3 at 380MHz
â68dBc IM3 and 39dBm OIP3 at 380MHz
n 1.5nV/âHz Output Noise
n 4.3pA/âHz Input Current Noise
n Programmable High Speed, Fast Recovery
Output Clamping
n 4.28VP-P Maximum Output Swing on a 50Ω
Differential Load
n DC-Coupled Signal Path
n Operates on Single 4.75V to 5.25V Supply
n Power: 615mW on 5V, Can Be Reduced to 370mW,
Shutdown Mode 120mW
n 3mm à 4mm 20-Lead QFN Package
Applications
n Differential ADC Driver
n CCD Buffer
n Cable Driver
n 50⦠Buffer
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear
Technology Corporation. All other trademarks are the property of their respective owners.
1.6GHz Low Noise High Linearity
Differential Buffer/16-Bit ADC
Driver with Fast Clamp
Description
The LTC®6417 is a differential unity gain buffer that can
drive a 50⦠load with extremely low noise and excellent
linearity. It is well suited for driving high speed 14- and
16-bit pipeline ADCs with input signals from DC to beyond
600MHz. Differential input impedance is 18.5kâ¦, allowing
1:4 and 1:8 transformers to be used at the input providing
additional system gain in 50Ω systems.
With no external biasing or gain setting components and
a flow-through pinout, the LTC6417 is very easy to use. It
can be DC-coupled and has a common mode output offset
of â60mV. The LTC6417 input pins are internally biased to
provide an output common mode voltage that is set by
the voltage on the VCM pin for AC-coupled applications.
Supply current is typically 123mA and the LTC6417 operates
on supply voltages ranging from 4.75V to 5.25V. Power
consumption can be reduced to 74mA via the PWRADJ
pin. The LTC6417 also has a hardware shutdown feature
which reduces current consumption to 24mA.
The LTC6417 features fast, adjustable output voltage clamp-
ing to help protect subsequent circuitry. The CLHI pin sets
the maximum swing, while a symmetric minimum swing
is set up internally. LTC6417 VOR pin will signal overrange
when the clamps limit output voltage.
The LTC6417 is packaged in a 20-lead 3mm à 4mm QFN
package. Pinout is optimized for placement directly adjacent
to Linear Technologyâs high speed 14- and 16-bit ADCs.
Typical Application
LTC6417 Driving an LTC2209 16-Bit ADC at 140MHz IF
5V
3.3V
50Ω
+â
680pF
0.1µF
1,6,
11,16
2.2µF
T1
WBC4-14LB
4
3
2
â¢â¢
6
1
0.01µF
100Ω
100Ω
0.01µF
V+ 5
PWRADJ 2
8 IN+
CLHI
19
OUT+
9
LTC6417
INâ
OUT
VCMVOR
â
18
SHDN
14
GND 12 15 1k
3, 7,10,
17, 20, 21
C43
27pF
E1
51nH
R36
60.4Ω
C41
12pF
R12
60.4Ω
C44
27pF
E2
51nH
2.2µF
E3
75nH
C45
18pF
E5
51nH
R42
300Ω
10Ω
C40
12pF
R53
120â¦
C10
R43
12pF 300Ω
10Ω
E3
75nH
C46
18pF
AIN+
16
LTC2209
AINâ
VCM PGA = 0
CLOCK
(153.6MHz)
6417 TA01a
LTC6417 Driving LTC2209
16-Bit ADC 32K Point FFT,
fIN = 140MHz, â1dBFS, PGA = 0
0
â10
â20
â30
â40
â50
â60
â70
â80
â90
â100
â110
â120
0
HD2 = â88dBc
HD3 = â94dBc
SFDR = 88dBc
SNR = 75.4dB
SEE FIGURE 1/TABLE 1
1:4 BALUN
fS = 153.6Msps
DEMO BOARD DC1685A
10 20 30 40 50 60 70 80
FREQUENCY (MHz)
6417 TA01b
6417f
1
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