LTC3805 Linear Technology, LTC3805 Datasheet - Page 20

• Manufacturer Part Number: LTC3805
• Description: Adjustable Frequency Current Mode Flyback DC/DC Controller
• Manufacturer: Linear Technology

www.datasheet4u.com
RELATED PARTS
LTC3805
TYPICAL APPLICATION
PART NUMBER
LT1725
LTC1871
LT1950
LT1952
LTC3803
LT3825
No R
20
SENSE
36V TO 72V
8.66k
470pF
221k
Figure 10. Low Power Nonisolated Telecom Supply with Trickle Charger
C26
R5
R8
and ThinSOT are Trademarks of Linear Technology Corporation.
V
V
IN
100pF
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
[phone]
IN
C25
+
R24
20k
NOTE: CAN ALSO USE NPN PREREGULATOR AS SHOWN IN FIGURE 9
DESCRIPTION
General Purpose High Power Isolated Flyback
Controller
Wide Input Range, No R
Flyback and SEPIC Controller
Single Switch PWM Controller with Auxiliary Boost
Converter
Single Switch Synchronous Forward Controller
Constant-Frequency Current Mode Flyback DC/DC
Controller in ThinSOT
Isolated No-OPTO Synchronous Flyback Controller
with Wide Input Supply Range
C
2.2μF
100V
V
IN1
IN
R20
118k
–
C23, 0.1μF
1
2
3
4
5
●
FAX: [phone]
SSFLT
I
FB
RUN
FS
TH
LTC3805EMSE
C
2.2μF
100V
GND
IN2
U1
11
I
SENSE
GATE
SYNC
V
OC
CC
SENSE
10
9
8
7
6
V
CC
●
TM
www.linear.com
Current Mode Boost,
R23
100k
C17
10μF
R16, 1.33k
3.01k
R19
BAS516
D4
3
R30
51Ω
150pF
0.068Ω
200V
Q1
FDC2512
COMMENTS
Suitable for Telecom 36V to 75V Inputs
Constant-Frequency Current Mode Flyback DC/DC Controller in ThinSOT
Single Switch PWM Controller with Auxiliary Boost Converter
Single Switch Synchronous Forward Controller
Wide Input Range, Current Mode Boost, Flyback and SEPIC Controller
Input Voltage Limited Only by External Components
C16
R
CS
4
1
5
2
PA1861NL
220Ω
R6
3805 TA03a
T1
7
8
10
9
UPS840
D1
100
vs Load Current and V
80
70
60
40
C01
100μF
6.3V
90
50
30
20
10
0
0.01
V
Effi ciency and Power Loss
IN
© LINEAR TECHNOLOGY CORPORATION 2006
36V
48V
60V
72V
C02
100μF
6.3V
LOAD CURRENT (A)
0.1
LT 0707 REV B • PRINTED IN USA
+V
C03
100μF
6.3V
OUT
IN
1
; V
O
R12
42.2k
= 3.3V
3805 TA03b
R14
13.7k
V
3.3V
3A
V
OUT
OUT
10
10
1
0
C18
330pF
+
–
TM
3805fb