LT1256CS#PBF Linear Technology, LT1256CS#PBF Datasheet - Page 13

• Manufacturer Part Number: LT1256CS#PBF
• Description: IC AMP VIDEO FADE CONTRLD 14SOIC
• Manufacturer: Linear Technology
• Type: Current Feedback Amplifierr

Specifications of LT1256CS#PBF

• Applications: Current Feedback
• Number Of Circuits: 1
• -3db Bandwidth: 40MHz
• Slew Rate: 300 V/µs
• Current - Supply: 14.5mA
• Current - Output / Channel: 40mA
• Voltage - Supply, Single/dual (±): 5 V ~ 30 V, ±2.5 V ~ 15 V
• Mounting Type: Surface Mount
• Package / Case: 14-SOIC (0.154", 3.90mm Width)
• Rail/rail I/o Type: No
• Number Of Elements: 1
• Common Mode Rejection Ratio: 50dB
• Input Offset Voltage: 5mV
• Input Bias Current: 2.5uA
• Single Supply Voltage (typ): 9/12/15/18/24/28V
• Dual Supply Voltage (typ): ±3/±5/±9/±12V
• Voltage Gain In Db: 93dB
• Power Supply Rejection Ratio: 70dB
• Power Supply Requirement: Single/Dual
• Shut Down Feature: No
• Single Supply Voltage (min): 5V
• Single Supply Voltage (max): 30V
• Dual Supply Voltage (min): ±2.5V
• Dual Supply Voltage (max): ±15V
• Technology: Bipolar
• Operating Temp Range: 0C to 70C
• Operating Temperature Classification: Commercial
• Mounting: Surface Mount
• Pin Count: 14
• Package Type: SOIC N
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

APPLICATIONS
In low gain applications, R
the feedback resistors and therefore we can simplify the
equation to:
Note that the denominator causes a gain error due to the
open-loop gain (typically 0.1% for frequencies below
20kHz) and for mismatches in R
match in the feedback resistors results in a 0.25% error at
K = 0.5.
If we set R
at low frequencies) the above equation simplifies to:
This shows that the output fades linearly from input 2,
times its gain, to input 1, times its gain, as K goes from
0 to 1.
If only one input is used (for example, V
grounded, then the gain is proportional to K.
V
where A
V
V
O
O
1
KA
1
R
R
F1
G
V
G
R
V
sR C
1
O
KV
1
= R
OL
V
1
1
OL
1
R
R
F2
KV A
F
F
1
1
1
and assume R
1
U
R
R
R
V
K
1
G
F
F
R
R
1
1
1
INFORMATION
1
G
G
U
1
2
2
1
and
and R
K V
1
R
R
R
K V A
F
F
F
2
2
2
K
2
A
2
OL
F1
2
V
are small compared to
W
2
>> R
and R
V
2
1
F1
1
) and Pin 14 is
F2
R
R
(a 0.1% error
. A 1% mis-
F
G
2
2
U
Note that the denominator is the same as the noninverting
case. In low gain applications, R
compared to the feedback resistors and therefore we can
simplify the equation to:
Again, if we set R
error at low frequencies) the above equation simplifies to:
The 4-resistor difference amplifier yields the same result
as the inverting amplifier case, and the common mode
rejection is independent of K.
Similarly for the inverting case where the noninverting
inputs are grounded and the input voltages V
the normally grounded ends of R
V
O
V
where A
O
General Equation for the Inverting Amplifier Case
1
R
sR C
1
OL
V
O
R
OL
V
R
sR C
G
1
OL
1
KV
R
F1
OL
G
R
R
1
1
R
KV A
R
= R
KV
G
1
F
F
1
1
1
1
R
1
R
F2
1
and
R
G
F
V
1
K
1
R
R
and assume R
F
1
1
1
G
K V
K
2
1
R
R
A
1
F
G
2
V
1
1
LT1251/LT1256
1
R
2
R
F
K V A
G1
2
K
G
1
2
R
R
1
and R
2
G
F
and R
2
1
2
R
R
OL
V
F
2
2
2
K V
>> R
G2
R
R
1
G
F
R
, we get:
2
2
2
and V
2
1
2
F1
are small
K
R
R
1
(a 0.1%
13
G
F
2
2
2
drive
1