LT6203CS8#TRPBF Linear Technology, LT6203CS8#TRPBF Datasheet - Page 15

• Manufacturer Part Number: LT6203CS8#TRPBF
• Description: IC OPAMP R-R INOUT DUAL LP 8SOIC
• Manufacturer: Linear Technology

Specifications of LT6203CS8#TRPBF

• Amplifier Type: General Purpose
• Number Of Circuits: 2
• Output Type: Rail-to-Rail
• Slew Rate: 25 V/µs
• Gain Bandwidth Product: 100MHz
• Current - Input Bias: 3.8µA
• Voltage - Input Offset: 2600µV
• Current - Supply: 2.8mA
• Current - Output / Channel: 40mA
• Voltage - Supply, Single/dual (±): 2.5 V ~ 12.6 V, ±1.25 V ~ 6.3 V
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 8-SOIC (3.9mm Width)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• -3db Bandwidth: -

APPLICATIONS INFORMATION
Amplifi er Characteristics
Figure 1 shows a simplifi ed schematic of the LT6202/
LT6203/LT6204, which has two input differential amplifi ers
in parallel that are biased on simultaneously when the
common mode voltage is at least 1.5V from either rail.
This topology allows the input stage to swing from the
positive supply voltage to the negative supply voltage.
As the common mode voltage swings beyond V
current source I
Feedback is maintained through the Q2/Q3 differential
amplifi er, but with an input g
effect occurs with I
swings within 1.5V of the negative rail. The effect of the
g
m
reduction is a shift in the V
DESD1
DESD3
1
+
–
saturates and current in Q1/Q4 is zero.
–V
–V
2
when the common mode voltage
+V
+V
D1
DESD2
DESD4
m
reduction of 1/2. A similar
OS
as I
D2
1
or I
Q1
R3
R1
Q2
2
I
saturate.
1
Figure 1. Simplifi ed Schematic
CC
I
Q3
2
– 1.5V,
R2
Q4
R4
Input bias current normally fl ows out of the + and – inputs.
The magnitude of this current increases when the input
common mode voltage is within 1.5V of the negative rail,
and only Q1/Q4 are active. The polarity of this current
reverses when the input common mode voltage is within
1.5V of the positive rail and only Q2/Q3 are active.
The second stage is a folded cascode and current mirror
that converts the input stage differential signals to a
single ended output. Capacitor C1 reduces the unity cross
frequency and improves the frequency stability without
degrading the gain bandwidth of the amplifi er. The
differential drive generator supplies current to the output
transistors that swing from rail-to-rail.
Q8
Q5
C1
R5
D3
+V
Q9
LT6202/LT6203/LT6204
Q7
Q6
+
C
DIFFERENTIAL
–
GENERATOR
M
V
DRIVE
BIAS
Q11
Q10
V –
V
–V
+
+V
DESD6
6203/04 F01
DESD5
15
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