LTC6416 Datasheet, PDF (1/20 Pages) Linear Technology – 2 GHz Low Noise Differential 16-Bit ADC Buffer

FEATURES
n _{2GHz –3dB Small Signal Bandwidth}
n _{300MHz ±0.1dB Bandwidth}
n _{1.8nV/√Hz Output Noise}
n _{46.25dBm Equivalent OIP3 at 140MHz}
n _{40.25dBm Equivalent OIP3 Up to 300MHz}
n _{–81dBc/–72dBc HD2/HD3 at 140MHz, 2VP-P Out}
n _{–84.5dBc IM3 at 140MHz, 2VP-P Out Composite}
n _{–74dBc/–67.5dBc HD2/HD3 at 300MHz, 2VP-P Out}
n _{–72.5dBc IM3 at 300MHz, 2VP-P Out Composite}
n _{Programmable High Speed, Fast Recovery}
Output Clamping
n _{DC-Coupled Signal Path}
n _{Operates on Single 2.7V to 3.9V Supply}
n _{Low Power: 150mW on 3.6V}
n _{2mm × 3mm 10-Pin DFN Package}
APPLICATIONS
n _{Differential ADC Driver}
n _{IF Sampling Receivers}
n _{Impedance Transformer}
n _{SAW Filter Interface}
n _{CCD Buffer}
LTC6416
2 GHz Low Noise Differential
16-Bit ADC Buffer
DESCRIPTION
The LTC^®6416 is a differential unity gain buffer designed
to drive 16-bit ADCs with extremely low output noise
and excellent linearity beyond 300MHz. Differential input
impedance is 12kΩ, allowing 1:4 and 1:8 transformers to
be used at the input to achieve additional system gain.
With no external biasing or gain setting components and
a flow-through pinout, the LTC6416 is very easy to use.
It can be DC-coupled and has a common mode output
offset of –40mV. If the input signals are AC-coupled, the
LTC6416 input pins are internally biased to provide an
output common mode voltage that is set by the voltage
on the V_CM pin.
In addition the LTC6416 has high speed, fast recovery
clamping circuitry to limit output signal swing. Both the
high and low clamp voltages are internally biased to allow
maximum output swing but are also user programmable
via the CLLO and CLHI pins.
Supply current is nominally 42mA and the LTC6416 oper-
ates on supply voltages ranging from 2.7V to 3.9V.
The LTC6416 is packaged in a 10-lead 3mm × 2mm DFN
package. Pinout is optimized for placement directly adjacent
to Linear’s high speed 12-, 14- and 16-bit ADCs.
L, LT, LTC and LTM are registered trademarks of Linear Technology Corporation. All other
trademarks are the property of their respective owners.
TYPICAL APPLICATION
LTC6416 Driving LTC2208 ADC – 140MHz IF
3.6V
680pF
0.1μF
2.2μF
1:8
50Ω
200Ω
CLHI _V+
IN⁺
V_CM
OUT⁺
25Ω
LTC6416
+–
200Ω
IN^–
OUT^–
GND
GND
25Ω
MINI-CIRCUITS
0.1μF ^CLLO
TCM8-1+
3.3V
1.5pF
1pF
1.5pF
AIN⁺
16
LTC2208
AIN^–
PGA = 1
6416 TA01a
CLOCK
(130MHz)
LTC6416 Driving LTC2208 ADC
with 1:8 Transformer f_IN =140MHz,
f_S = 130MHz, –1dBFS, PGA = 1
0
V⁺ = 3.6V
–10
HD2 = –94dBc
–20
HD3 = –89.1dBc
–30
SFDR = 89.1dB
SNR = 70.7dB
–40
MEASURED USING DC1257B
–50
WITH MINI-CIRCUIT TCM8-1+
–60
1:8 TRANSFORMER
–70
–80
–90
–100
–110
–120
0 10 20 30 40 50 60
FREQUENCY (MHz)
6416 TA01b
6416f
1