LT6604-15_15 Datasheet, PDF (1/16 Pages) Linear Technology – Dual Very Low Noise, Differential Amplifier and 15MHz Lowpass Filter

FEATURES
n _{Dual Differential Amplifier with 15MHz Lowpass}
Filters
4th Order Filters
Approximates Chebyshev Response
Guaranteed Phase and Gain Matching
Resistor-Programmable Differential Gain
n _{76dB Signal-to-Noise (3V Supply, 2VP-P Output)}
n _{Low Distortion, 2VP-P, 800Ω Load, VS = 3V}
1MHz: 86dBc 2nd, 90dBc 3rd
10MHz: 63dBc 2nd, 69dBc 3rd
n _{Specified for Operation with 3V, 5V and ±5V Supplies}
n _{Fully Differential Inputs and Outputs}
n _{Adjustable Output Common Mode Voltage}
n _{Small 4mm × 7mm × 0.75mm QFN Package}
APPLICATIONS
n _{Dual Differential ADC Driver Plus Filter}
n _{Single-Ended to Differential Converter}
n _{Matched, Dual, Differential Filter Stage}
n _{Common Mode Translation of Differential Signals}
n _{High Speed ADC Antialiasing and DAC Smoothing in}
Wireless Infrastructure or Networking Applications
n _{High Speed Test and Measurement Equipment}
n _{Medical Imaging}
LT6604-15
Dual Very Low Noise,
Differential Amplifier and
15MHz Lowpass Filter
DESCRIPTION
The LT^®6604-15 consists of two matched, fully differential
amplifiers, each with a 4th order, 15MHz lowpass filter. The
fixed frequency lowpass filter approximates a Chebyshev
response. By integrating a filter and a differential ampli-
fier, distortion and noise are made exceptionally low. At
unity gain, the measured in band signal-to-noise ratio is
an impressive 76dB. At higher gains, the input referred
noise decreases, allowing the part to process smaller
input differential signals without significantly degrading
the signal-to-noise ratio.
Gain and phase are highly matched between the two chan-
nels. Gain for each channel is independently programmed
using two external resistors. The LT6604-15 enables level
shifting by providing an adjustable output common mode
voltage, making it ideal for directly interfacing to ADCs.
The LT6604-15 is fully specified for 3V operation. The
differential design enables outstanding performance at
a 2V_P-P signal level for a single 3V supply. See the back
page of this datasheet for a complete list of related single
and dual differential amplifiers with integrated 2.5MHz to
20MHz lowpass filters.
L, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
TYPICAL APPLICATION
536Ω
0.01μF +
536Ω
–
LT6604-15
+INA ₊
V_MIDA
–
V_OCMA
–INA _– ⁺
536Ω
0.01μF +
536Ω
–
+INB ₊
V_MIDB
–
V_OCMB
–INB _– ⁺
V^–
V⁺A
–OUTA
3V
50Ω
+OUTA
50Ω
V⁺B
–OUTB
3V
50Ω
+OUTB
50Ω
3V
LTC22xx
DUAL ADC
18pF AIN
DOUT
18pF AIN
DOUT
660415 TA01
Channel to Channel Gain Matching
16
50 TYPICAL UNITS
14 ^{TA = 25°C}
GAIN = 1
12 ^{fIN = 15MHz}
10
8
6
4
2
0
–0.25–0.2–0.15–0.1–0.05 0 0.05 0.1 0.15 0.2 0.25
GAIN MATCH (dB)
660415 TA01b
660415fb
1