LTC6401-20 Datasheet, PDF (5/16 Pages) Linear Technology – 1.3GHz Low Noise, Low Distortion Differential ADC Driver for 140MHz IF

LTC6401-20
AC ELECTRICAL CHARACTERISTICS Specifications are at T_A = 25°C. V⁺ = 3V, V^– = 0V, +IN and –IN
floating, V_OCM = 1.25V, ^⎯E^⎯N^⎯A^⎯B^⎯L^⎯E = 0V, No R_L unless otherwise noted.
SYMBOL
PARAMETER
CONDITIONS
MIN
TYP
MAX UNITS
IMD_3,140M
OIP_3,140M
Third-Order Intermodulation
(f1 = 139.5MHz f2 = 140.5MHz)
Third-Order Output Intercept Point
(f1 = 139.5MHz f2 = 140.5MHz)
2V_P-P,OUT Composite, R_L = 400Ω
2V_P-P,OUT Composite, No R_L
2V_P-P,OUTFILT Composite, No R_L
2V_P-P,OUT Composite, No R_L (Note 7)
–71
dBc
–74
dBc
–72
dBc
41
dBm
P_1dB,140M
1dB Compression Point
R_L = 375Ω (Notes 5, 7)
18
NF_140M
Noise Figure
R_L = 375Ω (Note 5)
6.4
e_IN,140M
Input Referred Voltage Noise Density Includes Resistors (Short Inputs)
2.1
e_ON,140M
Output Referred Voltage Noise Density Includes Resistors (Short Inputs)
22
IMD_3,130M/150M Third-Order Intermodulation
2V_P-P,OUT Composite, R_L = 375Ω (Note 5)
–61
–69
(f1 = 130MHz f2 = 150MHz) Measure
at 170MHz
dBm
dB
nV/√⎯H⎯z
nV/√⎯H⎯z
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 LTC6401C and LTC6401I are guaranteed functional over the
operating temperature range of –40°C to 85°C.
Note 4: The LTC6401C is guaranteed to meet specified performance from
0°C to 70°C. It is designed, characterized and expected to meet specified
performance from –40°C to 85°C but is not tested or QA sampled at these
temperatures. The LTC6401I is guaranteed to meet specified 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.
Note 7: Since the LTC6401-20 is a feedback amplifier 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
LTC6401-20 with amplifiers that require 50Ω output load, the LTC6401-20
output voltage swing driving a given R_L is converted to OIP₃ and P_1dB as
if it were driving a 50Ω load. Using this modified convention, 2V_P-P is by
definition equal to 10dBm, regardless of the actual R_L.
TYPICAL PERFORMANCE CHARACTERISTICS
Frequency Response
25
TEST CIRCUIT B
20
15
10
5
0
10
100
1000 3000
FREQUENCY (MHz)
640120 G01
Gain 0.1dB Flatness
1.0
TEST CIRCUIT B
0.8
0.6
0.4
0.2
0
–0.2
–0.4
–0.6
–0.8
–1.0
10
100
FREQUENCY (MHz)
S21 Phase and Group Delay vs
Frequency
100 _{TEST CIRCUIT B}
1.5
0
1.2
–100
0.9
–200
0.6
–300
1000
640120 G02
–400
0
0.3
PHASE
GROUP DELAY
200 400 600
FREQUENCY (MHz)
0
800 1000
640120 G03
640120f
5