LT1105IN8 Linear Technology, LT1105IN8 Datasheet - Page 22

• Manufacturer Part Number: LT1105IN8
• Description: IC OFFLINE SWIT CM HV 8DIP
• Manufacturer: Linear Technology

Specifications of LT1105IN8

• Output Isolation: Isolated
• Frequency Range: 20 ~ 200kHz
• Voltage - Input: 7 ~ 30 V
• Voltage - Output: 20V
• Power (watts): 100W
• Operating Temperature: -40°C ~ 125°C
• Package / Case: 8-DIP (0.300", 7.62mm)
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

APPLICATIONS
LT1103/LT1105
22
Flyback Waveform for Continuous Mode Operation
e
a
c
f
b
d
t = (I
U
PRI
I
)[L(lk
I
INFORMATION
U
PRI
)]/V
SNUB
SECONDARY WINDING VOLTAGE
[V
BIAS WINDING VOLTAGE
[V
0V
SECONDARY CURRENT
V
PRIMARY SWITCH VOLTAGE
[V
V
AREA “a” = AREA “b” TO MAINTAIN
ZERO VOLTS ACROSS PRIMARY
0V
0V
AREA “c” = AREA “d” TO MAINTAIN
ZERO VOLTS ACROSS SECONDARY
N • V
AREA “e” = AREA “f” TO MAINTAIN
ZERO VOLTS ACROSS BIAS WINDING
N2 • V
I
0A
I
SWITCH CURRENT
0A
I
SNUBBER DIODE CURRENT
0A
PRIMARY CURRENT
I
0A
SEC =
PRI
PRI
W
ZENER
IN
PRI
OUT
OUT
OUT
IN
+ Vf + (I
+ Vf + (I
IN
+ Vf + (I
I
PRI
/N
SEC
SEC
SEC
• R
• R
• R
U
P
P
P
)]/N1
)]/N
)]
a
e
c
Flyback Waveform for Discontinuous Mode Operation
b
d
f
t = (I
PRI
)[L(lk
I
I
PRI
)]/ V
SNUB
SECONDARY WINDING VOLTAGE
[V
N • V
[V
I
SNUBBER DIODE CURRENT
AREA “c” = AREA “d” TO MAINTAIN
ZERO VOLTS ACROSS SECONDARY
PRIMARY CURRENT
I
SWITCH CURRENT
0A
V
PRIMARY SWITCH VOLTAGE
[V
AREA “a” = AREA “b” TO MAINTAIN
ZERO VOLTS ACROSS PRIMARY
AREA “e” = AREA “f” TO MAINTAIN
ZERO VOLTS ACROSS BIAS WINDING
I
0A
I
SECONDARY CURRENT
0A
0A
BIAS WINDING VOLTAGE
0V
0V
0V
N2 • V
PRI
PRI
V
PRI
SEC =
ZENER
OUT
OUT
OUT
IN
IN
+ Vf + (I
+ Vf + (I
I
+ Vf + (I
IN
PRI
/N
SEC
SEC
SEC
LT1103 WF01
• R
• R
• R
P
P
P
)]
)]/ N1
)]/ N