LTC6401-26_15 Datasheet, PDF (1/16 Pages) Linear Technology – 1.6GHz Low Noise, Low Distortion Differential ADC Driver for DC-140MHz

LTC6401-26
1.6GHz Low Noise,
Low Distortion Differential
ADC Driver for DC-140MHz
FEATURES
■ _{1.6GHz –3dB Bandwidth}
■ _{Fixed Gain of 20V/V (26dB)}
■ _{–85dBc IMD3 at 70MHz (Equivalent OIP3 = 46.5dBm)}
■ _{–72dBc IMD3 at 140MHz (Equivalent OIP3 = 40dBm)}
■ _{1nV/√⎯H⎯z Internal Op Amp Noise}
■ _{1.5nV/√⎯H⎯z Total Input Referred Noise}
■ _{6.8dB Noise Figure}
■ _{Differential Inputs and Outputs}
■ _{50Ω 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 4.7VP-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^®6401-26 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 LTC6401-26 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 of transformers or AC-coupling ca-
pacitors in many applications. The gain is internally fixed
at 26dB (20V/V).
The LTC6401-26 saves space and power compared to
alternative solutions using IF gain blocks and transform-
ers. The LTC6401-26 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
Single-Ended to Differential ADC Driver at 140MHz IF
3.3V
3.3V
0.1μF
1000pF
V_IN
150Ω
37.4Ω
V⁺
0.1μF
+IN
+OUT
0.1μF
LTCL6T4C0614-2061-26
–IN _VVOOCMC–_MOUT
V–
1.25V
0.1μF
15Ω
L1
24nH
15Ω
COILCRAFT
0603CS
100Ω
33pF
10Ω
AIN^{+ VDD}
33pF
LTC2208
10Ω
AIN^–
33pF _LTC2208
130Msps
16-BIT ADC
V_CM
640126 TA01a
Equivalent OIP3 vs Frequency
60
DIFFERENTIAL INPUT
(NOTE 7)
50
40
30
20
10
0
0
NO R_L
R_L = 200Ω
50
100
150
200
FREQUENCY (MHz)
640126 TA01b
640126f
1