LTC6401-14_15 Datasheet, PDF (1/16 Pages) Linear Technology – 2GHz Low Noise, Low Distortion Differential ADC Driver for DC-140MHz

LTC6401-14
2GHz Low Noise, Low
Distortion Differential ADC
Driver for DC-140MHz
FEATURES
■ _{2GHz –3dB Bandwidth}
■ _{Fixed Gain of 5V/V (14dB)}
■ _{–91dBc IMD3 at 70MHz (Equivalent OIP3 = 49.3dBm)}
■ _{–81dBc IMD3 at 140MHz (Equivalent OIP3 = 44.5dBm)}
■ _{1.1nV/√⎯H⎯z Internal Op Amp Noise}
■ _{7.3dB Noise Figure}
■ _{Differential Inputs and Outputs}
■ _{200Ω Input Impedance}
■ _{2.85V to 3.5V Supply Voltage}
■ _{45mA Supply Current (135mW)}
■ _{1V to 1.6V Output Common Mode, Adjustable}
■ _{DC- or AC-Coupled Operation}
■ _{Max Differential Output Swing 4.6VP-P}
■ _{Small 16-Lead 3mm × 3mm × 0.75mm QFN Package}
APPLICATIONS
■ _{Differential ADC Driver}
■ _{Differential Driver/Receiver}
■ _{Single Ended to Differential Conversion}
■ _{IF Sampling Receivers}
■ _{SAW Filter Interfacing}
DESCRIPTION
The LTC^®6401-14 is a high-speed differential amplifier
targeted at processing signals from DC to 140MHz. The
part has been specifically designed to drive 12-, 14- and
16-bit ADCs with low noise and low distortion, but can also
be used as a general-purpose broadband gain block.
The LTC6401-14 is easy to use, with minimal support
circuitry required. The output common mode voltage is
set using an external pin, independent of the inputs, which
eliminates the need for transformers or AC-coupling ca-
pacitors in many applications. The gain is internally fixed
at 14dB (5V/V).
The LTC6401-14 saves space and power compared to
alternative solutions using IF gain blocks and transform-
ers. The LTC6401-14 is packaged in a compact 16-lead
3mm × 3mm QFN package and operates over the –40°C
to 85°C temperature range.
, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
TYPICAL APPLICATION
3.3V
C2
0.1μF
C1
1000pF
V_IN
R1
68.5Ω
C3
0.1μF
C4
0.1μF
R2
29Ω
V⁺
+IN
+OUT
LTC6401-14
–IN
–OUT
V_OCM
V–
1.25V
C5
0.1μF
R_S1
15Ω
L1
R_{S2 24nH}
15Ω
COILCRAFT
0603CS
R3
100Ω
3.3V
C_F2
33pF
R_S3
10Ω
AIN^{+ VDD}
C_F1
33pF ^RS4
10Ω
C_F3
33pF
LTC2208
AIN^– _VCM
LTC2208
130Msps
16-Bit ADC
640114 TA01a
Equivalent Output IP3 vs Frequency
60
(NOTE 7)
50
40
30
20
10
0
0 20 40 60 80 100 120 140 160 180 200
FREQUENCY (MHz)
640114 TA01b
640114f
1