LTC6406
5
6406fc
ELECTRICAL CHARACTERISTICS
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, V
OCM
, SHDN and V
TIP
) are protected by
steering diodes to either supply. If the inputs should exceed either supply
voltage, the input current should be limited to less than 10mA. In addition,
the inputs +IN, –IN are protected by a pair of back-to-back diodes. If the
differential input voltage exceeds 1.4V, the input current should be limited
to less than 10mA.
Note 3: A heat sink may be required to keep the junction temperature
below the Absolute Maximum Rating when the output is shorted
indefi nitely. Long-term application of output currents in excess of the
absolute maximum ratings may impair the life of the device.
Note 4: The LTC6406C/LTC6406I are guaranteed functional over the
operating temperature range –40°C to 85°C.
Note 5: The LTC6406C is guaranteed to meet specifi ed performance from
0°C to 70°C. The LTC6406C 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 LTC6406I is guaranteed to meet
specifi ed performance from –40°C to 85°C.
Note 6: Input bias current is defi ned as the average of the input currents
fl owing into the inputs (–IN, and +IN). Input offset current is defi ned as the
difference between the input currents (I
OS
= I
B
+
– I
B
–
).
Note 7: Input common mode range is tested using the test circuit of
Figure 1 by taking three measurements of differential gain with a ±1V DC
differential output with V
ICM
= 0V; V
ICM
= 1.25V; V
ICM
= 3V, verifying that
the differential gain has not deviated from the V
ICM
= 1.25V case by more
than 0.5%, and that the common mode offset (V
OSCM
) has not deviated
from the common mode offset at V
ICM
= 1.25V by more than ±20mV.
The voltage range for the output common mode range is tested using the
test circuit of Figure 1 by applying a voltage on the V
OCM
pin and testing at
both V
OCM
= 1.25V and at the Electrical Characteristics table limits to verify
that the common mode offset (V
OSCM
) has not deviated by more than
±10mV from the V
OCM
= 1.25V case.
Note 8: Input CMRR is defi ned as the ratio of the change in the input
common mode voltage at the pins +IN or –IN to the change in differential
input referred voltage offset. Output CMRR is defi ned as the ratio of
the change in the voltage at the V
OCM
pin to the change in differential
input referred voltage offset. This specifi cation is strongly dependent on
feedback ratio matching between the two outputs and their respective
inputs, and it is diffi cult to measure actual amplifi er performance (see the
Effects of Resistor Pair Mismatch in the Applications Information section
of this data sheet). For a better indicator of actual amplifi er performance
independent of feedback component matching, refer to the PSRR
specifi cation.
Note 9: Differential power supply rejection (PSRR) is defi ned as the ratio
of the change in supply voltage to the change in differential input referred
voltage offset. Common mode power supply rejection (PSRRCM) is
defi ned as the ratio of the change in supply voltage to the change in the
common mode offset, V
OUTCM
– V
OCM
.
Note 10: Extended operation with the output shorted may cause the
junction temperature to exceed the 150°C limit.
Note 11: Because the LTC6406 is a feedback amplifi er with low output
impedance, a resistive load is not required when driving an ADC.
Therefore, typical output power can be very small in many applications. In
order to compare the LTC6406 with RF style amplifi ers that require 50Ω
load, the output voltage swing is converted to dBm as if the outputs were
driving a 50Ω load. For example, 2V
P-P
output swing is equal to 10dBm
using this convention.
Note 12: Includes offset/drift induced by feedback resistors mismatch. See
the Applications Information section for more details.
Note 13: QFN package only. Refer to data sheet curves for MSOP package
numbers.
TYPICAL PERFORMANCE CHARACTERISTICS
Differential Input Referred Offset
Voltage vs Temperature
Differential Input Referred
Offset Voltage vs Input Common
Mode Voltage
Common Mode Offset Voltage
vs Temperature
TEMPERATURE (°C)
6406 G01
DIFFERENTIAL V
OS
(mV)
V
S
= 3V
V
OCM
= 1.25V
V
ICM
= 1.25V
R
I
= R
F
= 150Ω
FIVE TYPICAL UNITS
–50 50 100–25 0 25 75
1.2
1.0
0.8
0.6
0.4
0.2
0
–0.2
INPUT COMMON MODE VOLTAGE (V)
6406 G02
DIFFERENTIAL V
OS
(mV)
V
S
= 3V
V
OCM
= 1.25V
R
I
= R
F
= 150Ω
0.1% FEEDBACK NETWORK RESISTORS
TYPICAL UNIT
0 2.0 3.00.5 1.0 1.5 2.5
2.0
1.5
1.0
0.5
–0.5
0
–1.0
–1.5
–2.0
T
A
= –40°C
T
A
= 0°C
T
A
= 25°C
T
A
= 70°C
T
A
= 85°C
TEMPERATURE (°C)
6406 G03
COMMON MODE OFFSET VOLTAGE (mV)
V
S
= 3V
V
OCM
= 1.25V
V
ICM
= 1.25V
FIVE TYPICAL UNITS
–50 50 100–25 0 25 75
7
6
5
4
3
2
1
0
