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LT3959IUHE#TRPBF

P1-P3P4-P6P7-P9P10-P12P13-P15P16-P18P19-P21P22-P24P25-P26
LT3959
1
3959fa
For more information www.linear.com/LT3959
Typical applicaTion
FeaTures DescripTion
Wide Input Voltage Range
Boost/SEPIC/Inverting Converter
with 6A, 40V Switch
2.5V to 24V Input, 12V Output SEPIC Converter
Excellent for Automotive 12V Post Regulator
applicaTions
n
Wide V
IN
Range: 1.6V (2.5V Start-Up) to 40V
n
Positive or Negative Output Voltage Programming
with a Single Feedback Pin
n
PGOOD Output Voltage Status Report
n
Internal 6A/40V Power Switch
n
Programmable Soft-Start
n
Programmable Operating Frequency (100kHz to 1MHz)
with One External Resistor
n
Synchronizable to an External Clock
n
Low Shutdown Current < 1µA
n
INTV
CC
Regulator Supplied from V
IN
or DRIVE
n
Programmable Input Undervoltage Lockout with
Hysteresis
n
Thermally Enhanced QFN (5mm × 6mm) and TSSOP
Packages
n
Automotive
n
Telecom
n
Industrial
L, LT , LT C , LT M , Linear Technology and the Linear logo are registered trademarks and
ThinSOT are trademarks of Linear Technology Corporation. All other trademarks are the
property of their respective owners. Protected by U.S. Patents, including 7825665.
The LT
®
3959 is a wide input range, current mode, DC/DC
controller which is capable of regulating either positive or
negative output voltages from a single feedback pin. It can
be configured as a boost, SEPIC or inverting converter.
It features an internal low side N-channel MOSFET rated
for 6A at 40V and driven from an internal regulated sup
-
ply provided from V
IN
or DRIVE. The fixed frequency,
current-mode architecture results in stable operation over
a wide range of supply and output voltages. The operating
frequency of LT3959 can be set over a 100kHz to 1MHz
range with an external resistor, or can be synchronized
to an external clock using the SYNC pin.
The LT3959 features soft-start and frequency foldback
functions to limit inductor current during start-up and
output short-circuit. A window comparator on the FBX
pin reports via the PGOOD pin, providing output voltage
status indication.
Efficiency vs Output Current
OUTPUT CURRENT (mA)
0
EFFICIENCY (%)
90
95
100
600 1000
3959 TA01b
85
200 400
800
80
75
70
65
60
V
IN
= 12V
LT3959
V
IN
V
IN
2.5V TO
24V
C
IN
22µF
50V
×2
27.4k
300kHz
4.7µF
50V
GND
DRIVE
FBX
SGND INTV
CC
EN_UVLO
PGOOD
SYNC
TIE TO SGND
IF NOT USED
RT
SS
V
C
L1A
L1B
GNDK
SW
124k
121k
0.1µF 7.5k
22nF
105K
150k
4.7µF
V
OUT
12V
500mA AT V
IN
= 2.5V
1.5A AT V
IN
> 8V
3959 TA01a
15.8K
C
OUT
47µF
16V
×2
LT3959
2
3959fa
For more information www.linear.com/LT3959
pin conFiguraTion
absoluTe MaxiMuM raTings
V
IN
............................................................................40V
EN/UVLO (Note 2) .....................................................40V
DRIVE .......................................................................40V
PGOOD ...................................................................... 40V
SW ............................................................................40V
INTV
CC
........................................................................8V
SYNC ..........................................................................8V
(Note 1)
V
C
, SS .........................................................................3V
RT ............................................................................1.5V
GND, GNDK to SGND .............................................±0.3V
FBX ................................................................. –3V to 3V
Operating Junction Temperature Range (Note 3)
LT3959E/LT3959I .............................. –40°C to 125°C
Storage Temperature Range .................. –65°C to 125°C
12 13 14
TOP VIEW
UHEMA PACKAGE
36-LEAD (5mm × 6mm) PLASTIC QFN
15 16 17
36 35 34 33 32 31 30
21
23
24
25
27
28
8
6
4
3
2
1NC
NC
NC
SGND
NC
SW
SW
NC
DRIVE
V
IN
EN/UVLO
SGND
NC
SW
SW
INTV
CC
PGOOD
SYNC
RT
SS
FBX
V
C
GNDK
GND
GND
GND
GND
GND
20
9
10
37
SGND
38
SW
T
JMAX
=125°C, θ
JA
= 42°C/W, θ
JC
= 3°C/W
EXPOSED PAD (PIN 37) IS SGND, MUST BE SOLDERED TO SGND PLANE
EXPOSED PAD (PIN 38) IS SW, MUST BE SOLDERED TO SW PLANE
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
TOP VIEW
FE PACKAGE
38-LEAD PLASTIC TSSOP
38
37
36
35
34
33
32
31
30
29
28
27
26
25
24
23
22
21
20
NC
NC
NC
V
C
FBX
SS
RT
SYNC
PGOOD
SGND
NC
SW
NC
NC
SW
NC
GNDK
GND
GND
NC
NC
NC
NC
EN/UVLO
V
IN
DRIVE
INTV
CC
NC
SGND
NC
SW
NC
NC
SW
NC
GND
GND
GND
39
SGND
40
SW
T
JMAX
=125°C, θ
JA
= 42°C/W, θ
JC
= 3°C/W
EXPOSED PAD (PIN 39) IS SGND, MUST BE SOLDERED TO SGND PLANE
EXPOSED PAD (PIN 40) IS SW, MUST BE SOLDERED TO SW PLANE
LT3959
3
3959fa
For more information www.linear.com/LT3959
elecTrical characTerisTics
PARAMETER CONDITIONS MIN TYP MAX UNITS
V
IN
Operating Voltage
l
1.6 40 V
V
IN
Start-Up Voltage R
T
= 27.4kΩ, FBX = 0
l
2.5 2.65 V
V
IN
Shutdown I
Q
EN/UVLO < 0.4V
EN/UVLO = 1.15V
0.1 1
6
µA
µA
V
IN
Operating I
Q
350 450 µA
DRIVE Shutdown Quiescent Current EN/UVLO < 0.4V
EN/UVLO = 1.15V
0.1
0.1
1
2
µA
µA
DRIVE Quiescent Current (Not Switching) R
T
= 27.4kΩ, DRIVE = 6V 2.0 2.5 mA
SW Pin Current Limit
l
6.0 7.0 8.0 A
SW Pin On Voltage I
SW
= 3A 100 mV
SW Pin Leakage Current SW = 40V 5 µA
Error Amplifier
FBX Regulation Voltage (V
FBX(REG)
) FBX > 0V
FBX < 0V
l
l
1.580
–0.815
1.6
–0.80
1.620
–0.785
V
V
FBX Pin Input Current FBX = 1.6V
FBX = –0.8V
–10
80
130
10
nA
nA
Transconductance g
m
(∆I
VC
/∆V
FBX
) FBX = V
FBX(REG)
240 µs
V
C
Output Impedance 5 MΩ
FBX Line Regulation [∆V
FBX(REG)
/(∆V
IN
• V
FBX(REG)
)] 1.6V < V
IN
< 40V, FBX >0
1.6V < V
IN
< 40V, FBX <0
0.02
0.02
0.05
0.05
%/V
%/V
V
C
Source Current FBX = 0V, V
C
= 1.3V –13 µA
V
C
Sink Current FBX = 1.7V, V
C
= 1.3V
FBX = –0.85V, V
C
= 1.3V
13
10
µA
µA
Oscillator
Switching Frequency R
T
= 27.4k to SGND, V
FBX
= 1.6V
R
T
= 86.6k to SGND, V
FBX
= 1.6V
R
T
= 6.81k to SGND, V
FBX
= 1.6V
l
250 300
100
1000
340 kHz
kHz
kHz
R
T
Voltage FBX = 1.6V, –0.8V 1.13 V
SW Minimum Off-Time 150 200 ns
SW Minimum On-Time 150 200 ns
The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C, V
IN
= 12V, EN/UVLO = 12V, INTV
CC
= 4.75V, unless otherwise noted.
orDer inForMaTion
LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE
LT3959EUHE#PBF LT3959EUHE#TRPBF 3959 36-Lead (5mm × 6mm) Plastic QFN –40°C to 125°C
LT3959IUHE#PBF LT3959IUHE#TRPBF 3959 36-Lead (5mm × 6mm) Plastic QFN –40°C to 125°C
LT3959EFE#PBF LT3959EFE#TRPBF LT3959FE 38-Lead Plastic TSSOP –40°C to 125°C
LT3959IFE#PBF LT3959IFE#TRPBF LT3959FE 38-Lead Plastic TSSOP –40°C to 125°C
Consult LT C Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping
container. Consult LT C Marketing for information on nonstandard lead based finish parts.
For more information on lead free part marking, go to: http://www.linear.com/leadfree/
For more information on tape and reel specifications, go to: http://www.linear.com/tapeandreel/
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LT3959IUHE#TRPBF

Mfr. #:
Buy LT3959IUHE#TRPBF
Manufacturer:
Analog Devices / Linear Technology
Description:
Switching Voltage Regulators Wide Input Voltage Range Boost/SEPIC/Inverting Converter with 5A, 40V Switch
Lifecycle:
New from this manufacturer.
Delivery:
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