POWER LOSS (W)
LT3782
2-Phase Step-UP
NOT RECOMMENDED FOR NEW DESIGNS
DC/DC Controller
Contact Linear Technology for Potential Replacement
FEATURES DESCRIPTION
n
2-Phase Operation Reduces Required Input and The LT 3782 is a current mode two phase step-up DC/DC
Output Capacitance converter controller. Its high switching frequency (up to
n
Programmable Switching Frequency: 500kHz) and 2-phase operation reduce system ltering
150kHz to 500kHz capacitance and inductance requirements.
n
6V to 40V Input Range
With 10V gate drive (V 13V) and 4A peak drive current,
CC
n
10V Gate Drive with V 13V
CC
the LT3782 can drive most industrial grade high power
n
High Current Gate Drive (4A)
MOSFETs with high ef ciency. For synchronous applica-
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Programmable Soft-Start and Current Limit
tions, the LT3782 provides synchronous gate signals with
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Programmable Slope Compensation for
programmable falling edge delay to avoid cross conduc-
High Noise Immunity
tion when using external MOSFET drivers. Other features
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MOSFET Gate Signals with Programmable
include programmable undervoltage lockout, soft-start,
Falling Edge Delay for External Synchronous
current limit, duty cycle clamp (50% or higher) and slope
Drivers
compensation.
n
Programmable Undervoltage Lockout
n The LT3782 is available in thermally enhanced 28-lead
Programmable Duty Cycle Clamp (50% or Higher)
n TSSOP and 4mm 5mm QFN packages.
Thermally Enhanced 28-Lead TSSOP and 4mm 5mm
QFN Packages
For new designs use the LT3782A which has improved
phase matching
APPLICATIONS
L, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
n
Industrial Equipment Protected by U.S. Patents including 6144194.
n
Telecom Infrastructure
n
Interleaved Isolated Power Supply
TYPICAL APPLICATION
50V 4A Boost Converter
V V
IN OUT
L1
10V TO 36V 50V, 4A
D1 C
OUT1
V GBIAS1
CC 10F Ef ciency and Power Loss
30BQ060
50V
1F
R6 +
L2 vs Load Current
GBIAS2
C3 2x
825k
D2 +
2F
C 97 18
GBIAS OUT2
C 30BQ060
IN
RUN M1
220F
10F V = 24V
IN
EFFICIENCY
BGATE1 Si7852dp
50V R8
2x 95 15
274k
2x
V = 12V
IN
R
LT3782 S1
93 12
0.004
V
R
EE1
SLOPE
V = 12V
IN
59k M2
91 9
SLOPE BGATE2 Si7852dp
2x
L1, L2: PB2020.223
DELAY V = 24V
IN
89 6
C , C : X7R, TDK
R IN OUT1
FREQ
DCL R
S2
80k
POWER LOSS
0.004
R
SET 87 3
V
EE2
10 10
SS
85 0
+
SENSE1
0.1F
0 1 2 3 4 5
10nF 10nF
I (A)
OUT
SENSE1
R
V F1
3782 TA01b
C
475k
+
13k
SENSE2
100pF
SENSE2
6.8nF
R
F2
FB
GND
3782 TA01 24.9k
3782fg
1
EFFICIENCY (%)LT3782
ABSOLUTE MAXIMUM RATINGS (Note 1)
V Supply Voltage ...................................................40V
Storage Temperature Range ...................65C to 150C
CC
GBIAS, GBIAS1, GBIAS2 Pin
Lead Temperature (Soldering, 10 sec) .................. 300C
(Externally Forced) ....................................................14V
SS ................................................................ 0.3V to 6V
+ +
SYNC, RUN Pin .........................................................30V
SENSE1 , SENSE2 ,
Operating Junction Temperature
SENSE1 , SENSE2 ..................................... 0.3V to 2V
Range (Notes 2, 3) ................................. 40C to 125C
PIN CONFIGURATION
TOP VIEW
TOP VIEW
1 28 GBIAS
SGATE2
2 27 V
SGATE1
CC
3 26 NC
NC
28 27 26 25 24 23
4 25 NC
GND SYNC 1 22 BGATE1
5 24 V DELAY 2 21 GBIAS1
SYNC
EE1
DCL 3 20 NC
6 BGATE1
DELAY 23
+
SENSE1 4 19
NC
7 GBIAS1
DCL 22
29
29
+ SENSE1 5 18 GBIAS2
8 GBIAS2
SENSE1 21
SLOPE 6 17 BGATE2
SENSE1 9 20 BGATE2
R 7 16 V
SET EE2
SLOPE 10 19 V
EE2
8
SENSE2 15 NC
R 11 18 NC
SET
9 10 11 12 13 14
SENSE2 12 17 RUN
+
SENSE2 13 16 FB
SS 14 15 V
C
UFD PACKAGE
28-LEAD (4mm 5mm) PLASTIC QFN
FE PACKAGE
T = 125C, = 37C/ W
28-LEAD PLASTIC TSSOP JMAX JA
EXPOSED PAD (PIN 29) IS GND, MUST BE SOLDERED TO PCB
T = 125C, = 38C/ W
JMAX JA
EXPOSED PAD (PIN 29) IS GND, MUST BE SOLDERED TO PCB
ORDER INFORMATION
LEAD FREE FINISH TAPE AND REEL PART MARKING PACKAGE DESCRIPTION TEMPERATURE RANGE
LT3782EFE#PBF LT3782EFE#TRPBF LT3782EFE 28-Lead Plastic TSSOP 40C to 85C
LT3782IFE#PBF LT3782IFE#TRPBF LT3782IFE 28-Lead Plastic TSSOP 40C to 125C
LT3782EUFD#PBF LT3782EUFD#TRPBF 3782 28-Lead (4mm 5mm) Plastic QFN 40C to 85C
LEAD BASED FINISH TAPE AND REEL PART MARKING PACKAGE DESCRIPTION TEMPERATURE RANGE
LT3782EFE LT3782EFE#TR LT3782EFE 28-Lead Plastic SSOP 40C to 85C
LT3782IFE LT3782IFE#TR LT3782IFE 28-Lead Plastic SSOP 40C to 125C
LT3782EUFD LT3782EUFD#TR 3782 40C to 85C
28-Lead (4mm 5mm) Plastic QFN
Consult LTC Marketing for parts speci ed with wider operating temperature ranges.
For more information on lead free part marking, go to: