LT1227CS8#TR Linear Technology, LT1227CS8#TR Datasheet - Page 10

• Manufacturer Part Number: LT1227CS8#TR
• Description: IC AMP VID DIFF CURR FDBK 8SOIC
• Manufacturer: Linear Technology

Specifications of LT1227CS8#TR

• Applications: Current Feedback
• Number Of Circuits: 1
• -3db Bandwidth: 140MHz
• Slew Rate: 1100 V/µs
• Current - Supply: 10mA
• Current - Output / Channel: 60mA
• Voltage - Supply, Single/dual (±): 4 V ~ 30 V, ±2 V ~ 15 V
• Mounting Type: Surface Mount
• Package / Case: 8-SOIC (0.154", 3.90mm Width)
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

LT1227
MUX Amplifier
The shutdown function can be effectively used to con-
struct a MUX amplifier. A two-channel version is shown,
but more inputs could be added with suitable logic. By
configuring each amplifier as a unity-gain follower, there
is no loading by the feedback network when the amplifier
is off. The open drains of the 74C906 buffers are used to
interface the 5V logic to the shutdown pin. Feedthrough
from the unselected input to the output is –70dB at
10MHz. The differential voltage between MUX inputs V
and V
device, this voltage should be less than 5V to avoid
turning on the clamp diodes discussed previously. If the
inputs are sinusoidal having a zero DC level, this implies
that the amplitude of each input should be less than
5V
high until the output level exceeds approximately 6V
10MHz, this sets the maximum usable output level. Switch-
ing time between inputs is about 4 s without an external
pullup. Adding a 10k pullup resistor from each shutdown
pin to V
increase the positive supply current in shutdown by 1.5mA.
TYPICAL
10
P-P
SELECT
INPUT
V
. The output impedance of the off amplifier remains
OUT
IN2
+
will reduce the switching time to 2 s but will
appears across the inputs of the shutdown
A
PPLICATI
V
IN1
MUX Output
= 1V
P-P
, V
O
IN2
U
= 0V
S
TA03
P-P
IN1
at
SELECT
INPUT
V
V
V
V
IN1
OUT
IN2
IN
= 1
–40
–50
–60
–70
–80
–90
1
MUX Input Crosstalk vs Frequency
5V
74HC04
MUX Amplifier
FREQUENCY (MHz)
1.5k
1.5k
+
–
+
–
–15V
LT1227
–15V
LT1227
15V
15V
5V
5V
10
74C906
74C906
S/D
S/D
1227 TA04
LT1227 TA05
100
V
OUT