LT6350
Low Noise
Single-Ended to Differential
Converter/ADC Driver
DESCRIPTION
The LT®6350 is a rail-to-rail input and output low noise
single-endedtodifferentialconverter/ADCdriverfeaturing
fast settling time. It converts a high or low impedance,
single-ended input signal to a low impedance, balanced,
differential output suitable for driving high performance
differentialsuccesiveapproximationregister(SAR)ADCs.
Thetwoopamptopologyfeaturesverylownoiseopamps,
that can support SNR >110dB in a 1MHz bandwidth.
FEATURES
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Rail-to-Rail Input and Outputs
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Fast Settling Time: 240ns, 0.01%, 8V Output Step
P-P
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1.9nV/√Hz Input-Referred Op Amp Noise
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High Impedance Input
–3dB Bandwidth: 33MHz
2.7V to 12V Supply Operation
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No External Gain-Resistors Required
4.8mA Supply Current
Low Power Shutdown
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Theinputopampistrimmedforconstantlowinput-referred
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Low Distortion (HD2/HD3): –102dBc/–97dBc at
voltage offset over the input range to prevent V steps
OS
100kHz, V
= 4V
OUTDIFF
P-P
from degrading distortion.
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Low Offset Voltage: 400μV Max
High DC Linearity: < 1LSB, 16-Bit, 8V
Low Input Current Noise: 1.1pA/√Hz
On a single 5V supply, the outputs can drive ADCs from
55mV to 4.945V on each input. With the addition of a
negative supply, the LT6350 can drive ADCs from 0V to
4.945V on each input. Output common mode voltage is
set by applying a voltage to the +IN2 pin.
P-P
3mm × 3mm 8-Pin DFN and 8-Lead MSOP Packages
APPLICATIONS
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16-Bit and 18-Bit SAR ADC Drivers
TheLT6350draws4.8mAfroma5Vsupplyandconsumes
just 60μA in shutdown mode.
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Single-Ended to Differential Conversion
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Differential Line Driver
The LT6350 is available in a compact 3mm × 3mm, 8-pin
leadless DFN package and also in an 8-pin MSOP package
and operates over a –40°C to 125°C temperature range.
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.
Protected by U.S. Patents including 5610557, 6344773.
TYPICAL APPLICATION
20kHz Sine Wave,
–1dBFS 8192-Point FFT
ADC Driver: Single-Ended Input to Differential Output
0
–10
–20
–30
–40
–50
–60
–70
5V
+
–
V
V
V
= 5V, V = –5V
= 7.3V
= 2.05V
OUTDIFF
P-P
249Ω
0.1μF
+IN2
SNR = 94.9dB
V
SINAD = 93.8dB
IN
+
5V
+
+
0V to 4V –
IN1 SHDN
V
OUT2
THD = –100.2dB
SFDR = 102.2dB
+
–
–
A
IN
–80
–90
2200pF
LTC2393-16
+
–
+
LT6350
A
IN
–100
–110
–120
–130
–140
–
+
–
V
OUT1
IN2
IN1
249Ω
–5V
0.1μF
0
100
200
300
400
500
FREQUENCY (kHz)
499Ω
0.1μF
6350 TA01
6350 TA02
2V
6350f
1