FEATURES
nn Wide Input Voltage Range: 5. 5V to 100V nn Positive or Negative Output Voltage Programming
with a Single Feedback Pin nn Current Mode Control Provides Excellent Transient
Response nn Programmable Operating Frequency (100kHz to
1MHz) with One External Resistor nn Synchronizable to an External Clock nn Low Shutdown Current < 1µA nn Internal 7. 2V Low Dropout Voltage Regulator nn Programmable Input Undervoltage Lockout with
Hysteresis nn Programmable Soft-Start nn Small 10-Lead DFN (3mm × 3mm) and
MSOPE Packages
APPLICATIONS
nn Automotive nn Telecom nn Industrial
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LT3758/LT3758A High Input Voltage, Boost, Flyback, SEPIC and Inverting Controller DESCRIPTION
The LT®3758/LT3758A are wide input range, current mode, DC/DC controllers which are capable of generating either positive or negative output voltages. They can be configured as either a boost, flyback, SEPIC or inverting converter. The LT3758/LT3758A drive a low side external N-channel power MOSFET from an internal regulated 7. 2V supply. The fixed frequency, current-mode architecture results in stable operation over a wide range of supply and output voltages. The operating frequency of LT3758/LT3758A can be set with an external resistor over a 100kHz to 1MHz range, and can be synchronized to an external clock using the SYNC pin. A minimum operating supply voltage of 5. 5V, and a low shutdown quiescent current of less than 1µA, make the LT3758/LT3758A ideally suited for batterypowered systems. The LT3758/LT3758A feature soft-start and frequency foldback functions to limit inductor current during startup and output short-circuit. The LT3758A has improved load transient performance compared to the LT3758.
TYPICAL APPLICATION
12V Output Nonisolated Flyback Power Supply
VIN 36V TO
72V
CIN 2. 2µF 100V X7R 63. 4k 200kHz
D1
1M 44. 2k
0. 47µF
VIN SHDN/UVLO
0. 022µF 100V
6. 2k T1
1,2,3 (SERIES) DSN
4,5,6 (PARALLEL)
LT3758
SYNC
...
LT3758A PDF File
