LTC1992-1CMS8 Linear Technology, LTC1992-1CMS8 Datasheet - Page 35

• Manufacturer Part Number: LTC1992-1CMS8
• Description: IC AMP/DVR I/O GAIN-1 DIFF 8MSOP
• Manufacturer: Linear Technology

Specifications of LTC1992-1CMS8

• Amplifier Type: Differential
• Number Of Circuits: 1
• Output Type: Differential, Rail-to-Rail
• Slew Rate: 1.5 V/µs
• Gain Bandwidth Product: 3.2MHz
• Current - Input Bias: 2pA
• Voltage - Input Offset: 250µV
• Current - Supply: 700µA
• Current - Output / Channel: 30mA
• Voltage - Supply, Single/dual (±): 2.7 V ~ 11 V, ±1.35 V ~ 5.5 V
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 8-MSOP, Micro8™, 8-uMAX, 8-uSOP,
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• -3db Bandwidth: -

applicaTions inForMaTion
Table 1. Input Signal Limitations for Some Common Applications
Single Supply Ground Referenced Single-Ended Input Signal, V
both the input common mode limits and the output clipping)
Single Supply Ground Referenced Single-Ended Input Signal, V
listed account for both the input common mode limits and the output clipping)
Fully Differential Amplifier Applications
Circuit Analysis
All of the previous applications circuit discussions have as-
sumed perfectly matched symmetrical feedback networks.
To consider the effects of mismatched or asymmetrical
feedback networks, the equations get a bit messier.
Figure 6 lists the basic gain equation for the differential
output voltage in terms of +V
the feedback factors β1 and β2. The feedback factors are
simply the portion of the output that is fed back to the input
summing junction by the R
β1 and β2 have the range of zero to one. The V
term also includes its offset voltage, V
mismatch term, K
matching of the on-chip R
common mode level servo (see Figure 2).
+V
+V
(V)
2.7
2.7
2.7
2.7
(V)
2.7
2.7
2.7
2.7
5
5
5
5
5
5
5
5
S
S
–V
–V
(V)
(V)
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
S
S
CM
GAIN
(V/V)
GAIN
(V/V)
10
10
10
10
1
2
5
1
2
5
1
2
5
1
2
5
. The K
CMP
FB
V
V
1.35
1.35
1.35
1.35
(V)
2.5
2.5
2.5
2.5
(V)
OCM
OCM
CM
1
1
1
1
2
2
2
2
IN
-R
, –V
IN
and R
term is determined by the
resistive voltage divider.
IN
, V
CMM
V
V
OSDIFF
OSCM
INREF
INREF
(V)
(V)
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
resistors in the
, and its gain
, V
OUTCM
OUTCM
V
V
INSIG(MAX)
INSIG(MAX)
and
2.700
1.350
0.540
0.270
5.000
2.500
1.000
0.500
2.000
1.000
0.400
0.200
4.000
2.000
0.800
0.400
(V)
(V)
OCM
OCM
at Mid-Supply. (The V
at Typical ADC Reference Levels. (The V
While mathematically correct, the basic signal equation
does not immediately yield any intuitive feel for fully
differential amplifier application operation. However, by
nulling out specific terms, some basic observations and
sensitivities come forth. Setting β1 equal to β2, V
to zero and V
from Figure 3. The ground referenced, single-ended input
signal equation yields the interesting result that the driven
side feedback factor (β1) has a very different sensitivity
than the grounded side (β2). The CMRR is twice the
feedback factor difference divided by the feedback fac-
tor sum. The differential output offset voltage has two
terms. The first term is determined by the input offset
term, V
term equates to the formula in Figure 3 when β1 equals
β2. The amount of signal level shifting and the feedback
factor mismatch determines the second term. This term
V
V
INSIG(MIN)
INSIG(MIN)
–2.700
–1.350
–0.540
–0.270
–5.000
–2.500
–1.000
–0.500
–2.000
–1.000
–0.400
–0.200
–4.000
–2.000
–0.800
–0.400
OSDIFF
(V)
(V)
OUTCM
, and the application’s gain. Note that this
INSIG
(V
(V
P-P
P-P
to V
Min and Max values listed account for
V
V
INSIGP-P(MAX)
INSIGP-P(MAX)
AROUND V
AROUND V
OCM
LTC1992 Family
10.00
5.40
2.70
1.08
0.54
5.00
2.00
1.00
4.00
2.00
0.80
0.40
8.00
4.00
1.60
0.80
gives the old gain equation
INREF
INREF
INSIG
)
)
Min and Max values
V
V
OUTDIFF(MAX)
OUTDIFF(MAX)
(V
(V
10.00
10.00
10.00
10.00
P-PDIFF
P-PDIFF
5.40
5.40
5.40
5.40
4.00
4.00
4.00
4.00
8.00
8.00
8.00
8.00
)
)

OSDIFF
1992fa