LTC3805-5 Series

Adjustable Frequency Current Mode Flyback/Boost/SEPIC DC/DC Controller

Catalog

Adjustable Frequency Current Mode Flyback/Boost/SEPIC DC/DC Controller

Part	Output Phases	Function	Mounting Type	Duty Cycle (Max)	Topology	Package / Case	Package / Case	Output Configuration	Number of Outputs	Control Features	Operating Temperature [Min]	Operating Temperature [Max]	Supplier Device Package	Voltage - Supply (Vcc/Vdd) [Max]	Voltage - Supply (Vcc/Vdd) [Min]	Frequency - Switching [Min]	Frequency - Switching [Max]	Output Type
Analog Devices LTC3805MPMSE#PBF	1	Step-Up/Step-Down	Surface Mount	80 %	Flyback	0.118 in 3 Lead	10-MSOP 10-TFSOP Exposed Pad	Isolation Capable Positive	1	Enable Soft Start	-55 °C	150 °C	10-MSOP-EP	9.5 V	3.95 V	70 kHz	700 kHz	Transistor Driver
Analog Devices LTC3805IMSE#TRPBF	1	Step-Up/Step-Down	Surface Mount	80 %	Flyback	0.118 in 3 Lead	10-MSOP 10-TFSOP Exposed Pad	Isolation Capable Positive	1	Enable Soft Start	-40 °C	125 ¯C	10-MSOP-EP	9.5 V	3.95 V	70 kHz	700 kHz	Transistor Driver
Analog Devices LTC3805EMSE-5#TRPBF	1	Step-Up Step-Up/Step-Down	Surface Mount	80 %	Boost Flyback SEPIC	0.118 in 3 Lead	10-MSOP 10-TFSOP Exposed Pad	Isolation Capable Positive	1	Enable Soft Start	-40 °C	85 °C	10-MSOP-EP	9.5 V	3.95 V	70 kHz	700 kHz	Transistor Driver
Analog Devices LTC3805IDD-5#TRPBF	1	Step-Up Step-Up/Step-Down	Surface Mount	80 %	Boost Flyback SEPIC		10-WFDFN Exposed Pad	Isolation Capable Positive	1	Enable Soft Start	-40 °C	125 ¯C	10-DFN (3x3)	9.5 V	3.95 V	70 kHz	700 kHz	Transistor Driver
Analog Devices LTC3805EMSE#TRPBF	1	Step-Up/Step-Down	Surface Mount	80 %	Flyback	0.118 in 3 Lead	10-MSOP 10-TFSOP Exposed Pad	Isolation Capable Positive	1	Enable Soft Start	-40 °C	85 °C	10-MSOP-EP	9.5 V	3.95 V	70 kHz	700 kHz	Transistor Driver
Analog Devices LTC3805EDD-5#PBF	1	Step-Up Step-Up/Step-Down	Surface Mount	80 %	Boost Flyback SEPIC		10-WFDFN Exposed Pad	Isolation Capable Positive	1	Enable Soft Start	-40 °C	85 °C	10-DFN (3x3)	9.5 V	3.95 V	70 kHz	700 kHz	Transistor Driver
Analog Devices LTC3805EMSE#PBF	1	Step-Up/Step-Down	Surface Mount	80 %	Flyback	0.118 in 3 Lead	10-MSOP 10-TFSOP Exposed Pad	Isolation Capable Positive	1	Enable Soft Start	-40 °C	85 °C	10-MSOP-EP	9.5 V	3.95 V	70 kHz	700 kHz	Transistor Driver
Analog Devices LTC3805EDD#TRPBF	1	Step-Up/Step-Down	Surface Mount	80 %	Flyback		10-WFDFN Exposed Pad	Isolation Capable Positive	1	Enable Soft Start	-40 °C	85 °C	10-DFN (3x3)	9.5 V	3.95 V	70 kHz	700 kHz	Transistor Driver
Analog Devices LTC3805HMSE#PBF	1	Step-Up/Step-Down	Surface Mount	80 %	Flyback	0.118 in 3 Lead	10-MSOP 10-TFSOP Exposed Pad	Isolation Capable Positive	1	Enable Soft Start	-40 °C	150 °C	10-MSOP-EP	9.5 V	3.95 V	70 kHz	700 kHz	Transistor Driver
Analog Devices LTC3805EDD-5#TRPBF	1	Step-Up Step-Up/Step-Down	Surface Mount	80 %	Boost Flyback SEPIC		10-WFDFN Exposed Pad	Isolation Capable Positive	1	Enable Soft Start	-40 °C	85 °C	10-DFN (3x3)	9.5 V	3.95 V	70 kHz	700 kHz	Transistor Driver

Catalog

Adjustable Frequency Current Mode Flyback/Boost/SEPIC DC/DC Controller

Key Features

• VINand VOUTLimited Only by External Components

• 4.5V Undervoltage Lockout Threshold

• Adjustable Slope Compensation

• Adjustable Overcurrent Protection with Automatic Restart

• Adjustable Operating Frequency (70kHz to 700kHz) With One External Resistor

• Synchronizable to an External Clock

• ±1.5% Reference Accuracy

• Only 100mV Current Sense Voltage Drop

• RUN Pin with Precision Threshold and Adjustable Hysteresis

• Programmable Soft-Start with One External Capacitor

• Low Quiescent Current: 360μA

• Small 10-Lead MSOP and 3mm × 3mm DFN

Description

The LTC3805-5 is a current mode DC/DC controller designed to drive an N-channel MOSFET in flyback, boost and SEPIC converter applications. Operating frequency and slope compensation can be programmed by external resistors. Programmable overcurrent sensing protects the converter from overload and short-circuit conditions. Soft-start can be programmed using an external capacitor and the soft-start capacitor also programs an automatic restart feature.The LTC3805-5 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 LTC3805-5 can be powered from a high VINthrough a resistor or it can be powered directly from a low impedance DC voltage from 4.7V to 8.8V.The LTC3805-5 is available in the 10-lead MSOP package and the 3mm × 3mm DFN package.Turn On VoltageLTC38058.4VLTC3805-54.5VApplicationsAutomotive Power SuppliesTelecom Power SuppliesIsolated Electronic EquipmentAuxiliary/Housekeeping Power SuppliesPower over Ethernet