LT8310
100V Forward Converter
IN
Controller
Fea T Descrip T
n
Input Voltage Range: 6V to 100V The LT 8310 is a simple-to-use resonant reset forward
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Duty Mode Control Regulates an Isolated Output converter controller that drives the gate of a low side
without an Opto N-channel MOSFET from an internally regulated 10V sup-
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High Efficiency Synchronous Control ply. The LT8310 features duty mode control that generates
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Short-Circuit (Hiccup Mode) Overcurrent Protection a stable, regulated, isolated output using a single power
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Programmable OVLO and UVLO with Hysteresis transformer. With the addition of output voltage feedback,
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Programmable Frequency (100kHz to 500kHz) via opto-coupler (isolated) or directly wired (nonisolated),
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Synchronizable to an External Clock current mode regulation is activated, improving output
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Positive or Negative Polarity Output Voltage Feedback accuracy and load response. The flexibility to choose
with a Single FBX Pin transformer turns ratio makes high step-down or step-up
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Programmable Soft-Start ratios possible without operating at duty cycle extremes.
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Low Shutdown Current < 1A
The user can program the switching frequency from 100kHz
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Available in FE20 TSSOP with HV Pin Spacing
to 500kHz to optimize efficiency, performance or external
component size. A synchronous output is available for
controlling secondary side synchronous rectification to
a T
improve efficiency. User programmable protection features
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Industrial, Automotive and Military Systems
include monitors on input voltage (UVLO and OVLO) and
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48V Telecommunication Isolated Power Supplies
switch current (overcurrent limit). The LT8310 soft-start
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Isolated and Nonisolated DC/DC Converters
feature helps protect the transformer from flux saturation.
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear
Technology Corporation. All other trademarks are the property of their respective owners.
Typical a T
78 Watt Isolated Forward Converter, 8% V
OUT
47H
V
OUT
V
IN
12V Output Voltage Load Regulation
36V TO 72V 2:1
2.2F
0.6A TO 6.5A
100V
1F 14.0
+
22F
4 86.6k
100V 100F
8
13.5
UVLO V
IN
1.74k
V
13.0
OUT
150pF
OVLO
NPO
12.5
LT8310
1.43k
GATE
12.0
INTV SENSE
CC
0.025
4.7F
11.5
102k
1%
RDVIN GND
11.0
DFILT
V = 72V
8310 TA01a
IN
10nF NC SYNC SOUT NC
V = 48V
10.5
IN
RT SS V FBX
C V = 36V
IN
49.9k
10.0
0.47F
200kHz
1 2 4 5 6 7
NC 0 3
V
IN
I (A)
OUT
8310 TA01b
8310f
1
For more information www.linear.com/LT8310
V (V)
OUT
ion pplica
ions pplica
ion uresLT8310
a Te Maxi Mu M r a T p c F T
(Notes 1, 2)
V , UVLO ...............................................................100V TOP VIEW
IN
INTV , RDVIN, SYNC ..............................................20V
CC UVLO 1 20 NC
DFILT...........................................................................8V
V , OVLO, SS, RT ........................................................3V OVLO 3 18 V
C IN
FBX ................................................................. 3V to 3V
DFILT 5 16 RDVIN
SENSE ....................................................... 0.3V to 0.3V
21
GND
RT 6 15 INTV
CC
GATE, SOUT ..........................................................Note 3
SYNC 7 14 GATE
Operating Junction Temperature Range (Notes 4, 5)
SS 8 13 SENSE
LT8310E ............................................. 40C to 125C
V 9 12 NC
C
LT8310I .............................................. 40C to 125C
FBX 10 11 SOUT
LT8310H ............................................ 40C to 150C
FE PACKAGE
LT8310MP ......................................... 55C to 150C
20-LEAD PLASTIC TSSOP
Storage Temperature Range .................. 65C to 150C
T = 125C (E-, I-GRADES), T = 150C (H-GRADE),
JMAX JMAX
= 10C/W, = 38C/W
JC JA
Lead Temperature Range (Soldering, 10 sec) ........300C
EXPOSED PAD (PIN 21) IS GND, MUST BE SOLDERED TO THE GROUND PLANE
o r D i n F Ma T
LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE
LT8310EFE#PBF LT8310EFE#TRPBF LT8310FE 20-Lead Plastic TSSOP 40C to 125C
LT8310IFE#PBF LT8310IFE#TRPBF LT8310FE 20-Lead Plastic TSSOP 40C to 125C
LT8310HFE#PBF LT8310HFE#TRPBF LT8310FE 20-Lead Plastic TSSOP 40C to 150C
LT8310MPFE#PBF LT8310MPFE#TRPBF LT8310FE 20-Lead Plastic TSSOP 55C to 150C
Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container.
Consult LTC Marketing for information on nonstandard lead based finish parts.
For more information on lead free part marking, go to: