targeted at processing signals from DC to 300MHz. 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 LTC6400-14 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 LTC6400-14 saves space and power compared to
alternative solutions using IF gain blocks and transformers.
The LTC6400-14 is packaged in a compact 16-lead 3mm
×
3mm QFN package and operates over the – 40°C to 85°C
temperature range.
L,
LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
2.4GHz –3dB Bandwidth
Fixed Gain of 5V/V (14dB)
–97dBc IMD3 at 70MHz (Equivalent OIP3 = 52.4dBm)
–66dBc IMD3 at 300MHz (Equivalent OIP3 = 36.9dBm)
1.1nV/√Hz Internal Op Amp Noise
2.5nV/√Hz Total Input Noise
7.5dB Noise Figure
Differential Inputs and Outputs
200Ω Input Impedance
2.85V to 3.5V Supply Voltage
85mA Supply Current (255mW)
1V to 1.6V Output Common Mode Voltage,
Adjustable
DC- or AC-Coupled Operation
Max Differential Output Swing 4.8V
P-P
Small 16-Lead 3mm
×
3mm
×
0.75mm QFN Package
APPLICATIONS
n
n
n
n
n
Differential ADC Driver
Differential Driver/Receiver
Single Ended to Differential Conversion
IF Sampling Receivers
SAW Filter Interfacing
TYPICAL APPLICATION
Single-Ended to Differential ADC Driver
3.3V
3.3V
70
60
OUTPUT IP3 (dBm)
C2
0.1μF
C1
1000pF
C3
0.1μF
V
IN
R1
68.5Ω
C4
0.1μF
–IN
R2
29Ω
V–
1.25V
C5
0.1μF
R3
100Ω
V
+
+IN
+OUT
LTC6400-14
–OUT
V
OCM
L1
R
S2
24nH
15Ω
COILCRAFT
0603CS
C
F1
33pF R
S4
10Ω
C
F3
33pF
R
S1
15Ω
C
F2
33pF
R
S3
10Ω
50
40
30
20
10
0
0
64014 TA01a
Equivalent Output IP3 vs
Frequency
(NOTE 7)
AIN
+
V
DD
LTC2208
AIN
–
V
CM
LTC2208
130Msps
16-Bit ADC
50
100
150
200
FREQUENCY (MHz)
250
300
640020 TA01b
640014fb
1
LTC6400-14
ABSOLUTE MAXIMUM RATINGS
(Note 1)
PIN CONFIGURATION
TOP VIEW
–IN
–IN
+IN
7
+OUTF
+IN
12 V–
17
11
ENABLE
10 V
+
9 V–
8
+OUT
16 15 14 13
V
+
1
Supply Voltage (V
+
– V
–
) .........................................3.6V
Input Current (Note 2)..........................................±10mA
Operating Temperature Range
(Note 3) ...............................................–40°C to 85°C
Specified Temperature Range
(Note 4) ...............................................–40°C to 85°C
Storage Temperature Range...................–65°C to 150°C
Maximum Junction Temperature........................... 150°C
Lead Temperature (Soldering, 10 sec) .................. 300°C
V
OCM
2
V
+
3
V– 4
5
–OUT
6
UD PACKAGE
16-LEAD (3mm 3mm) PLASTIC QFN
T
JMAX
= 150°C,
θ
JA
= 68°C/W,
θ
JC
= 4.2°C/W
EXPOSED PAD (PIN 17) IS V
–
, MUST BE SOLDERED TO PCB
ORDER INFORMATION
LEAD FREE FINISH
LTC6400CUD-14#PBF
LTC6400IUD-14#PBF
TAPE AND REEL
LTC6400CUD-14#TRPBF
LTC6400IUD-14#TRPBF
PART MARKING*
LCCR
LCCR
PACKAGE DESCRIPTION
16-Lead (3mm
×
3mm) Plastic QFN
16-Lead (3mm
×
3mm) Plastic QFN
SPECIFIED TEMPERATURE RANGE
0°C to 70°C
– 40°C to 85°C
Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container.
Consult LTC Marketing for information on non-standard lead based finish parts.
For more information on lead free part marking, go to:
http://www.linear.com/leadfree/
For more information on tape and reel specifications, go to:
http://www.linear.com/tapeandreel/
LTC6400 AND LTC6401 SELECTOR GUIDE
PART NUMBER
LTC6400-8
LTC6400-14
LTC6400-20
LTC6400-26
LTC6401-8
LTC6401-14
LTC6401-20
LTC6401-26
GAIN
(dB)
8
14
20
26
8
14
20
26
GAIN
(V/V)
2.5
5
10
20
2.5
5
10
20
Please check each datasheet for complete details.
Z
IN
(DIFFERENTIAL)
(Ω)
400
200
200
50
400
200
200
50
I
CC
(mA)
85
85
90
85
45
45
50
45
In addition to the LTC6400 family of amplifiers, a lower power LTC6401 family is available. The LTC6401 is pin compatible to the LTC6400, and has the
same low noise performance. The lower power consumption of the LTC6401 comes at the expense of slightly higher non-linearity, especially at input
frequencies above 140MHz. Please refer to the separate LTC6401 data sheets for complete details.
–OUTF
640014fb
2
LTC6400-14
DC ELECTRICAL CHARACTERISTICS
+
The
l
–
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V = 3V, V = 0V, +IN = –IN = V
OCM
= 1.25V,
ENABLE
= 0V, No R
L
unless
otherwise noted.
PARAMETER
Gain
Gain Temperature Drift
Output Swing Low
Output Swing High
Maximum Differential Output Swing
Output Current Drive
Input Differential Offset Voltage
Input Differential Offset Voltage Drift
Input Common Mode Voltage Range, MIN
Input Common Mode Voltage Range, MAX
Input Resistance (+IN, –IN)
Input Capacitance (+IN, –IN)
Output Resistance (+OUT, –OUT)
Filtered Output Resistance (+OUTF, –OUTF)
Filtered Output Capacitance (+OUTF, –OUTF)
Common Mode Rejection Ratio
Common Mode Gain
Output Common Mode Range, MIN
Output Common Mode Range, MAX
Common Mode Offset Voltage
Common Mode Offset Voltage Drift
V
OCM
Input Current
ENABLE
Input Low Voltage
ENABLE
Input High Voltage
ENABLE
Input Low Current
ENABLE
Input High Current
Operating Supply Range
Supply Current
Shutdown Supply Current
Power Supply Rejection Ratio (Differential
Outputs)
ENABLE
= 0.8V
ENABLE
= 2.4V, Input and Output Floating
V
+
= 2.85V to 3.5V
ENABLE
= 0.8V
ENABLE
= 2.4V
V
OCM
= 1.1V to 1.5V
T
MIN
to T
MAX
Differential
Differential, Includes Parasitic
Differential
Differential
Differential, Includes Parasitic
Input Common Mode Voltage 1.1V~1.7V
V
OCM
= 1V to 1.6V
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
SYMBOL
G
DIFF
TC
GAIN
V
SWINGMIN
V
SWINGMAX
V
OUTDIFFMAX
I
OUT
V
OSDIFF
TCV
OSDIFF
I
VRMIN
I
VRMAX
R
INDIFF
C
INDIFF
R
OUTDIFF
R
OUTFDIFF
C
OUTFDIFF
CMRR
G
CM
V
OCMMIN
V
OCMMAX
V
OSCM
TCV
OSCM
IV
OCM
ENABLE
Pin
V
IL
V
IH
I
IL
I
IH
Power Supply
V
S
I
S
I
SHDN
PSRR
CONDITIONS
V
IN
= ±200mV Differential
V
IN
= ±200mV Differential
Each Output, V
IN
= ±800mV Differential
Each Output, V
IN
= ±800mV Differential
1dB Compressed
Each Output
T
MIN
to T
MAX
l
l
l
l
l
l
l
l
MIN
13.5
TYP
14
–0.9
77
MAX
14.5
160
UNITS
dB
mdB/°C
mV
V
V
P-P
mA
Input/Output Characteristic
2.35
20
–3
2.48
4.8
3
0.7
1
mV
μV/°C
V
V
Ω
pF
Ω
Ω
pF
dB
V/V
1.8
170
18
85
40
200
1
25
100
2.7
62
1
1
1.1
1.6
1.5
–15
9
4
15
0.8
2.4
0.5
1.3
2.85
70
55
3
85
0.9
76
3
3.5
96
3
15
32
115
230
Output Common Mode Voltage Control
V
V
V
V
mV
μV/°C
μA
V
V
μA
μA
V
mA
mA
dB
640014fb
3
LTC6400-14
AC ELECTRICAL CHARACTERISTICS
ENABLE
= 0V, No R
L
unless otherwise noted.
SYMBOL
–3dBBW
0.1dBBW
0.5dBBW
1/f
SR
t
S1%
t
OVDR
t
ON
t
OFF
–3dBBW
VOCM
10MHz Input Signal
HD2,10M/HD3,10M
IMD3,10M
OIP3,10M
P1dB,10M
NF10M
e
IN,10M
e
ON,10M
70MHz Input Signal
HD2,70M/HD3,70M
IMD3,70M
OIP3,70M
P1dB,70M
NF70M
e
IN,70M
e
ON,70M
Second/Third Order Harmonic
Distortion
Third-Order Intermodulation
(f1 = 69.5MHz f2 = 70.5MHz)
Third-Order Output Intercept Point
(f1 = 69.5MHz f2 = 70.5MHz)
1dB Compression Point
Noise Figure
Input Referred Voltage Noise Density
2V
P-P, OUT
, R
L
= 200Ω
2V
P-P, OUT
, No R
L
2V
P-P, OUT
Composite, R
L
= 200Ω
2V
P-P, OUT
Composite, No R
L
2V
P-P, OUT
Composite, No R
L
(Note 7)
R
L
= 375Ω (Notes 5, 7)
R
L
= 375Ω (Note 5)
Includes Resistors (Short Inputs)
–86/–85
–89/–94
–91
–97
52.4
18.5
7.5
2.5
12.5
dBc
dBc
dBc
dBc
dBm
dBm
dB
nV/√Hz
nV/√Hz
Second/Third Order Harmonic
Distortion
Third-Order Intermodulation
(f1 = 9.5MHz f2 = 10.5MHz)
Third-Order Output Intercept Point
(f1 = 9.5MHz f2 = 10.5MHz)
1dB Compression Point
Noise Figure
Input Referred Voltage Noise Density
2V
P-P, OUT
, R
L
= 200Ω
2V
P-P, OUT
, No R
L
2V
P-P, OUT
Composite, R
L
= 200Ω
2V
P-P, OUT
Composite, No R
L
2V
P-P, OUT
Composite, No R
L
(Note 7)
R
L
= 375Ω (Notes 5, 7)
R
L
= 375Ω (Note 5)
Includes Resistors (Short Inputs)
–107/–96
–110/–108
–99
–110
59.1
17.8
7.5
2.5
13
dBc
dBc
dBc
dBc
dBm
dBm
dB
nV/√Hz
nV/√Hz
PARAMETER
–3dB Bandwidth
Bandwidth for 0.1dB Flatness
Bandwidth for 0.5dB Flatness
1/f Noise Corner
Slew Rate
1% Settling Time
Overdrive Recovery Time
Turn-On Time
Turn-Off Time
V
OCM
Pin Small Signal –3dB BW
Differential (Note 6)
2V
P-P, OUT
(Note 6)
1.9V
P-P, OUT
(Note 6)
Differential Output Reaches 90% of Steady
State Value
Differential Output Drops to 10% of
Original Value
0.1V
P-P
at V
OCM
, Measured Single-Ended
at Output (Note 6)
Specifications are at T
A
= 25°C. V
+
= 3V, V
–
= 0V, V
OCM
= 1.25V,
MIN
1.2
TYP
2.37
200
377
15
6000
1.7
17
10
12
16
MAX
UNITS
GHz
MHz
MHz
kHz
V/μs
ns
ns
ns
ns
MHz
CONDITIONS
200mV
P-P, OUT
(Note 6)
200mV
P-P, OUT
(Note 6)
200mV
P-P, OUT
(Note 6)
Output Referred Voltage Noise Density Includes Resistors (Short Inputs)
Output Referred Voltage Noise Density Includes Resistors (Short Inputs)
640014fb
4
LTC6400-14
AC ELECTRICAL CHARACTERISTICS
ENABLE
= 0V, No R
L
unless otherwise noted.
PARAMETER
Second/Third Order Harmonic
Distortion
Third-Order Intermodulation
(f1 = 139.5MHz f2 = 140.5MHz)
Third-Order Output Intercept Point
(f1 = 139.5MHz f2 = 140.5MHz)
1dB Compression Point
Noise Figure
Input Referred Voltage Noise Density
SYMBOL
140MHz Input Signal
HD2,140M/HD3,140M
IMD3,140M
OIP3,140M
P1dB,140M
NF140M
e
IN,140M
e
ON,140M
240MHz Input Signal
HD2,240M/HD3,240M
IMD3, 240M
OIP3, 240M
P1dB, 240M
NF240M
e
N, 240M
e
ON, 240M
Second/Third-Order Harmonic
Distortion
Third-Order Intermodulation
(f1 = 239.5MHz f2 = 240.5MHz)
Third-Order Output Intercept Point
(f1 = 239.5MHz f2 = 240.5MHz)
1dB Compression Point
Noise Figure
Input Referred Voltage Noise Density
2V
P-P, OUT
, R
L
= 200Ω
2V
P-P, OUT
, No R
L
2V
P-P, OUT
Composite, R
L
= 200Ω
2V
P-P, OUT
Composite, No R
L
2V
P-P, OUT
Composite, No R
L
(Note 7)
R
L
= 375Ω (Notes 5, 7)
R
L
= 375Ω (Note 5)
Includes Resistors (Short Inputs)
–63/–57
–67/–63
–68
–71
39.6
17.9
8
2.5
12.9
dBc
dBc
dBc
dBc
dBm
dBm
dB
nV/√Hz
nV/√Hz
2V
P-P, OUT
, R
L
= 200Ω
2V
P-P, OUT
, No R
L
2V
P-P, OUT
Composite, R
L
= 200Ω
2V
P-P, OUT
Composite, No R
L
2V
P-P, OUT
Composite, No R
L
(Notes 7)
R
L
= 375Ω (Notes 5, 7)
R
L
= 375Ω (Note 5)
Includes Resistors (Short Inputs)
–78/–74
–81/–79
–80
–85
46.5
18.8
7.7
2.5
12.6
dBc
dBc
dBc
dBc
dBm
dBm
dB
nV/√Hz
nV/√Hz
Specifications are at T
A
= 25°C. V
+
= 3V, V
–
= 0V, V
OCM
= 1.25V,
MIN
TYP
MAX
UNITS
CONDITIONS
Output Referred Voltage Noise Density Includes Resistors (Short Inputs)
Output Referred Voltage Noise Density Includes Resistors (Short Inputs)
