LTC1177-5/LTC1177-12
Isolated MOSFET Drivers
FEATURES
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DESCRIPTIO
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UL Recognized
廬
File E151738 to UL1577
No Secondary Power Supply
Drives Any Logic Level FET
Low Input Current: 1mA Typ (LTC1177-5),
2.5mA Typ (LTC1177-12)
Turns On in 1ms Typ and Turns Off in 1ms Typ
2500V
RMS
of Isolation Voltage
Isolates Input from High Voltage Transients at Load
Clean, Bounce-Free Switching
Current Limit
Small Outline Package
The LTC
廬
1177-5/LTC1177-12 are isolated high side
MOSFET drivers. When used with an external N-channel
MOSFET, the LTC1177-5/LTC1177-12 form an isolated
solid state switch for reliable bounce-free switching op-
eration. The output does not require an auxiliary power
supply to maintain an on-state condition.
Two lead frame capacitors are used to transfer energy
from the input to drive the gate of the MOSFET and provide
the necessary isolation. Unlike optoisolated FET drivers,
the input current for the LTC1177-5 is only 1mA and
2.5mA for LTC1177-12. It also does not have the aging
problems endemic to optocouplers.
Both devices provide 2500V
RMS
(1 minute) or 3000V
RMS
(1 second) of output-to-input isolation.
The LTC1177-5/LTC1177-12 are available in the 18-pin
PDIP or 28-pin SW package.
, LTC and LT are registered trademarks of Linear Technology Corporation.
APPLICATI
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S
Solid State Relay
Isolated Solenoid Driver
Isolated Motor Driver
Isolated Lamp Driver
TYPICAL APPLICATI
Isolated High Side Switch
5V OR 12V
0V
V
+
= 40V
f = 50Hz
1
18
V
IN
GND1
LTC1177-5
LTC1177-12
ISOLATION BARRIER
V
OUT
+
7
47碌F
50V
MTD3055EL
8
9
NC
NC
OUT
NC
GND2
SENSE
12
11
10
V
IN
V
OUT
R
OUT
50鈩?/div>
1177 TA01
1177 TA02
U
Input vs Output
UO
UO
1
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