LTC3705_15 Datasheet, PDF (20/20 Pages) Linear Technology – 2-Switch Forward Controller and Gate Driver

LTC3705
TYPICAL APPLICATIO
P1
V_IN+
36V TO
72V
L2
0.82µH
1µF
100V
1µF
100V
1µF
100V
P2
V_IN–
10Ω
Q1
MMBT2907A
10Ω
Q2
MMBT2907A
0.025Ω
1W
MURS120
T1
PA0520
2_{• •}7
8T
6T
5
11
MURS120 ^BAS21
1_•
5T
BAS21 ₆
D1A
D1B
330pF
200V
L1
20Ω ^25µH
1W
+ _C7
68µF
2x ^D3
11 7
2.2nF
250V
P4
V_OUT+
12V
5A
0.1µF
P3
V_OUT–
365k
1%
301k
220pF
1000pF
15k
1%
301k
100Ω
330pF
0.033µF
1
16
GND
TS
2
3 ^IS
LTC3705 _TG ¹⁵
14
4 ^VSLMT
BOOT
13
UVLO
NC
5
12
SSFLT
NC
6
11
NDRV
7 _FB/IN+
V_{CC 10}
BG
8 _FS/IN–
9
PGND
100k
FQT7N10
0.22µF
1mH
DO1608C-105
BAS21
C7: TPSE686M025R0125 AVX
D1A, D1B: MBRB20100CT
D3: P6SMB15AT3
L1: GOWANDA 050KM2502SM
L2: VISHAY IHLP2525CZERR82M01
Q1, Q2: SILICONIX Si7456DP
+ _2.2µF
15V
0.1µF
25V
3705 F08
Regulation
18
16
14
12
10
8
6
4
V_IN = 36V
2
V_IN = 48V
0
V_IN = 72V
0
1
2
3
LOAD (A)
4
5
3705 F08b
Figure 8. 36V-72V to 12V/5A Open-Loop Regulated Isolated Forward Converter Using VSLMT
RELATED PARTS
PART NUMBER
DESCRIPTION
COMMENTS
LTC1693
LTC1698
High Speed Single/Dual N-Channel MOSFET Drivers CMOS Compatible Input, V_CC Range: 4.5V to 12V
Secondary Synchronous Rectifier Controller
Use with the LT1681, Optocoupler Driver, Pulse Transformer Synchronization
LT1950
Single Switch Controller
Used for 20W to 500W Forward Converters
LTC3706
Polyphase Secondary-Side Synchronous
Forward Controller
Fast Transient Response, Self-Starting Architecture, Current Mode Control
LT3710
Secondary-Side Synchronous Post Regulator
For Regulated Auxiliary Output in Isolated DC/DC Converters
LT3781
“Bootstrap” Start Dual Transistor Synchronous
Forward Controller
72V Operation, Synchronous Switch Output
LT3804
Secondary Side Dual Output Controller
with Opto Driver
Regulates Two Secondary Outputs, Optocoupler Feedback Driver
and Second Output Synchronous Driver Controller
LTC3901
Secondary-Side Synchronous Driver for
Push-Pull and Full-Bridge Converter
Similar Function to LTC3900, Used in Full-Bridge and Push-Pull Converter
LTC4440/LTC4440-5 High Speed, High Voltage and High Side
Gate Drivers
High Side Source Up to 100V, Up to 15V Gate Drive Supply, 6-Lead
ThinSOT^TM or 8-Lead Exposed Pad MSOP Packages
LTC4441
6A MOSFET Driver
ThinSOT is a trademark of Linear Technology Corporation.
Adjustable Gate Drive from 5V to 8V, 5V to 28V V_IN Range
3705fb
20 Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
[phone] ^● FAX: [phone] ^● www.linear.com
LT 1006 REV B • PRINTED IN USA
© LINEAR TECHNOLOGY CORPORATION 2005