LTC3805 Series

Adjustable Frequency Current Mode Flyback DC/DC Controller

Manufacturer: Analog Devices Inc./Maxim Integrated

Catalog

Adjustable Frequency Current Mode Flyback DC/DC Controller

Part	Package / Case	Number of Outputs	Operating Temperature [Max]	Operating Temperature [Min]	Supplier Device Package	Output Phases	Frequency - Switching [Max]	Frequency - Switching [Min]	Duty Cycle (Max) [Max]	Output Configuration	Function	Topology	Mounting Type	Output Type	Control Features	Voltage - Supply (Vcc/Vdd) [Max]	Voltage - Supply (Vcc/Vdd) [Min]
Analog Devices Inc./Maxim Integrated LTC3805MPMSE#PBF	10-MSOP 10-TFSOP Exposed Pad	1	150 °C	-55 °C	10-MSOP-EP	1	700 kHz	70 kHz	80 %	Isolation Capable Positive	Step-Up/Step-Down	Flyback	Surface Mount	Transistor Driver	Enable Soft Start	9.5 V	3.95 V
Analog Devices Inc./Maxim Integrated LTC3805IDD#PBF	10-WFDFN Exposed Pad	1	125 °C	-40 C	10-DFN (3x3)	1	700 kHz	70 kHz	80 %	Isolation Capable Positive	Step-Up/Step-Down	Flyback	Surface Mount	Transistor Driver	Enable Soft Start	9.5 V	3.95 V
Analog Devices Inc./Maxim Integrated LTC3805IDD#TRPBF	10-WFDFN Exposed Pad	1	125 °C	-40 C	10-DFN (3x3)	1	700 kHz	70 kHz	80 %	Isolation Capable Positive	Step-Up/Step-Down	Flyback	Surface Mount	Transistor Driver	Enable Soft Start	9.5 V	3.95 V
Analog Devices Inc./Maxim Integrated LTC3805IMSE#TRPBF	10-MSOP 10-TFSOP Exposed Pad	1	125 °C	-40 C	10-MSOP-EP	1	700 kHz	70 kHz	80 %	Isolation Capable Positive	Step-Up/Step-Down	Flyback	Surface Mount	Transistor Driver	Enable Soft Start	9.5 V	3.95 V
Analog Devices Inc./Maxim Integrated LTC3805EMSE-5#TRPBF	10-MSOP 10-TFSOP Exposed Pad	1	85 C	-40 ¯C	10-MSOP-EP	1	700 kHz	70 kHz	80 %	Isolation Capable Positive	Step-Up Step-Up/Step-Down	Boost Flyback SEPIC	Surface Mount	Transistor Driver	Enable Soft Start	9.5 V	3.95 V
Analog Devices Inc./Maxim Integrated LTC3805IDD-5#TRPBF	10-WFDFN Exposed Pad	1	125 °C	-40 C	10-DFN (3x3)	1	700 kHz	70 kHz	80 %	Isolation Capable Positive	Step-Up Step-Up/Step-Down	Boost Flyback SEPIC	Surface Mount	Transistor Driver	Enable Soft Start	9.5 V	3.95 V
Analog Devices Inc./Maxim Integrated LTC3805EDD#PBF	10-WFDFN Exposed Pad	1	85 C	-40 ¯C	10-DFN (3x3)	1	700 kHz	70 kHz	80 %	Isolation Capable Positive	Step-Up/Step-Down	Flyback	Surface Mount	Transistor Driver	Enable Soft Start	9.5 V	3.95 V
Analog Devices Inc./Maxim Integrated LTC3805EMSE#TRPBF	10-MSOP 10-TFSOP Exposed Pad	1	85 C	-40 ¯C	10-MSOP-EP	1	700 kHz	70 kHz	80 %	Isolation Capable Positive	Step-Up/Step-Down	Flyback	Surface Mount	Transistor Driver	Enable Soft Start	9.5 V	3.95 V
Analog Devices Inc./Maxim Integrated LTC3805EDD-5#PBF	10-WFDFN Exposed Pad	1	85 C	-40 ¯C	10-DFN (3x3)	1	700 kHz	70 kHz	80 %	Isolation Capable Positive	Step-Up Step-Up/Step-Down	Boost Flyback SEPIC	Surface Mount	Transistor Driver	Enable Soft Start	9.5 V	3.95 V
Analog Devices Inc./Maxim Integrated LTC3805EMSE#PBF	10-MSOP 10-TFSOP Exposed Pad	1	85 C	-40 ¯C	10-MSOP-EP	1	700 kHz	70 kHz	80 %	Isolation Capable Positive	Step-Up/Step-Down	Flyback	Surface Mount	Transistor Driver	Enable Soft Start	9.5 V	3.95 V

Description

The LTC3805 is a current mode controller for flyback DC/DC converters designed to drive an N-channel MOSFET in high input and output voltage converter applications. Operating frequency and slope compensation can be programmed by external resistors. Programmable overcurrent sensing protects the converter from short-circuits. Soft-start can be programmed using an external capacitor and the soft-start capacitor also programs an automatic restart feature.The LTC3805 provides ±1.5% output voltage accuracy and consumes only 360μA of quiescent current during normal operation and only 40μA during micropower startup. Using a 9.5V internal shunt regulator, the LTC3805 can be powered from a high VINthrough a resistor or it can be powered directly from a low impedance DC voltage of 9V or less.The LTC3805 is available in the 10-lead MSOP package and the 3mm × 3mm DFN package.Turn On VoltageLTC38058.4VLTC3805-54.5VApplicationsTelecom Power Supplies42V and 12V Automotive Power SuppliesIsolated Electronic Equipment