LTC6420-20
4
642020fb
AC ELECTRICAL CHARACTERISTICS
The l denotes the specifi cations which apply over the full operating
temperature range, otherwise specifi cations are at T
A
= 25°C. V
+
= 3V, V
–
= 0V, V
OCM
= 1.25V, ENABLE = 0V, No R
L
unless otherwise noted.
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
∆G Gain Matching f = 100MHz (Note 9)
l
±0.1 ±0.25 dB
∆P Phase Matching f = 100MHz ±0.1 deg
Channel Separation (Note 8) f = 100MHz 80 dB
–3dBBW –3dB Bandwidth 200mV
P-P,OUT
(Note 6) 1.8 GHz
0.5dBBW Bandwidth for 0.5dB Flatness 200mV
P-P,OUT
(Note 6) 0.7 GHz
0.1dBBW Bandwidth for 0.1dB Flatness 200mV
P-P,OUT
(Note 6) 0.3 GHz
NF Noise Figure R
L
= 375 (Note 5), f = 100MHz 6.2 dB
e
IN
Input Referred Voltage Noise Density Includes Resistors (Short Inputs), f = 100MHz 2.2 nV/√Hz
e
ON
Output Referred Voltage Noise Density Includes Resistors (Short Inputs), f = 100MHz 22 nV/√Hz
1/f 1/f Noise Corner 10 kHz
SR Slew Rate Differential (Note 6) 4500 V/µs
t
S1%
1% Settling Time 2V
P-P, OUT
(Note 6) 0.8 ns
t
OVDR
Overdrive Recovery Time 1.9V
P-P,OUT
(Note 6): Single Ended 4 ns
P
1dB
1dB Compression Point R
L
= 375 (Notes 5, 7), f = 100MHz 18 dBm
t
ON
Turn-On Time +OUT, –OUT Within 10% of Final Values 82 ns
t
OFF
Turn-Off Time I
CC
Falls to 10% of Nominal 190 ns
–3dBBW
VOCM
V
OCM
Pin Small Signal –3dB BW 0.1V
P-P
at V
OCM
, Measured Single-Ended at
Output (Note 6)
15 MHz
IMD3 3rd Order Intermodulation Distortion f = 100MHz (1MHz Spacing)
V
OUT
= 2V
P-P
Composite
–84 dBc
OIP3 3rd Order Output Intercept f = 100MHz (Note 7) 46 dBm
IIP3 3rd Order Input Intercept f = 100MHz (Z
IN
= 50Ω)
f = 100MHz (Z
IN
= 200Ω)
26
20
dBm
dBm
HD
2
2nd Order Harmonic Distortion f = 100MHz; V
OUT
= 2V
P-P
–80 dBc
HD
3
3rd Order Harmonic Distortion f = 100MHz; V
OUT
= 2V
P-P
–88 dBc
Note 1: Stresses beyond those listed under Absolute Maximum Ratings
may cause permanent damage to the device. Exposure to any Absolute
Maximum Rating condition for extended periods may affect device
reliability and lifetime.
Note 2: Input pins (+IN, –IN) are protected by steering diodes to either
supply. If the inputs go beyond either supply rail, the input current should
be limited to less than 10mA.
Note 3: The LTC6420C and LTC6420I are guaranteed functional over the
operating temperature range of –40°C to 85°C.
Note 4: The LTC6420C is guaranteed to meet specifi ed performance from
0°C to 70°C. It is designed, characterized and expected to meet specifi ed
performance from –40°C to 85°C but is not tested or QA sampled at these
temperatures. The LTC6420I is guaranteed to meet specifi ed performance
from –40°C to 85°C.
Note 5: Input and output baluns used. See Test Circuit A.
Note 6: Measured using Test Circuit B. R
L
= 87.5Ω on each output.
Note 7: Since the LTC6420-20 is a feedback amplifi er with low output
impedance, a resistive load is not required when driving an AD converter.
Therefore, typical output power is very small. In order to compare the
LTC6420-20 with amplifi ers that require 50Ω output load, the output
voltage swing driving a given R
L
is converted to OIP
3
and P
1dB
as if it were
driving a 50Ω load. Using this modifi ed convention, 2V
P-P
is by defi nition
equal to 10dBm, regardless of actual R
L
.
Note 8: Channel separation (the inverse of crosstalk) is measured by
driving a signal into one input, while terminating the other input. Channel
separation is the ratio of the resulting output signal at the driven channel
to the channel that is not driven.
Note 9: Not production tested. Guaranteed by design and by correlation to
production tested parameters.
Note 10: The output swing range is at least 2V
P-P
differential even when
sourcing or sinking 20mA. Tested at V
OCM
= 1.5V.
