LT3759IMSE Datasheet, PDF (1/32 Pages) Linear Technology – Wide Input Voltage Range Boost/SEPIC/Inverting Controller

FEATURES
n _{Wide VIN Range: 1.6V to 42V}
n _{Positive or Negative Output Voltage Programming}
with a Single Feedback Pin
n _{PGOOD Output Voltage Status Report}
n _{Accurate 50mV SENSE Threshold Voltage}
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 _{INTVCC Regulator Supplied from VIN or DRIVE}
n _{Programmable Input Undervoltage Lockout with}
Hysteresis
APPLICATIONS
n _{Datacom and Industrial Boost, SEPIC and Inverting}
Converters
n _{Distributed Power Supplies}
n _{Portable Electronic Equipment}
n _Automotive
LT3759
Wide Input Voltage Range
Boost/SEPIC/Inverting
Controller
DESCRIPTION
The LT^®3759 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.
The LT3759 drives a low side external N-channel power
MOSFET. An internal LDO regulator draws power from
V_IN or DRIVE to provide up to a 4.75V supply for the gate
driver. The fixed frequency, current-mode architecture
results in stable operation over a wide range of supply
and output voltages. The operating frequency of LT3759
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 LT3759 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. The device is available in a 12-Lead exposed
pad MSOP package.
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and
ThinSOT and No R_SENSE are trademarks of Linear Technology Corporation. All other trademarks
are the property of their respective owners. Protected by U.S. Patents including 7825665.
TYPICAL APPLICATION
V_IN
2.5V TO
36V
2.5V to 36V Input, 12V Output SEPIC Converter
Excellent for Automotive 12V Post Regulator
L1A
4.7µF ×2
C_IN
4.7µF
×4
100k
105k
V_IN
EN/UVLO
GATE
118k
SENSE
LT3759
M1
L1B
5mΩ
TIE TO GND
IF NOT USED
PGOOD
SYNC
RT
DRIVE
105K
41.2k
200kHz
SS
VC
FBX
GND INTV_CC
0.1µF
7.5k
15.8K
22nF
4.7µF
COUT1
10µF
V_OUT
12V
0.5A, 2.5V ≤ V_IN ≤ 8V
2A, 8V < V_IN ≤ 36V
+ ^COUT2
47µF
×4
3759 TA01a
For more information www.linear.com/3759
Efficiency vs Output Current
100
V_IN = 12V
95
90
85
80
75
0
0.5
1
1.5
2
2.5
OUTPUT CURRENT (A)
3759 TA01b
3759fc
1