Features

• High Voltage Operation: Up to 60V
• Output Voltages up to 36V (Step-Down)
• Programmable Constant Frequency: 100kHz to 500kHz
• Synchronizable up to 600kHz
• Burst Mode® Operation: 120µA Supply Current
• 10µA Shutdown Supply Current
• ±1.3% Reference Accuracy
• Drives N-Channel MOSFET
• Programmable Soft-Start
• Programmable Undervoltage Lockout
• Internal High Voltage Regulator for Gate Drive
• Thermal Shutdown
• Current Limit Unaffected by Duty Cycle
• 16-Pin Thermally Enhanced TSSOP Package

Typical Application

Description

The LT3844 is a DC/DC controller used for medium power, low part count, high efficiency supplies. It offers a wide 4V-60V input range (7.5V minimum startup voltage) and can implement step-down, step-up, inverting and SEPIC topologies.

The LT3844 includes Burst Mode operation, which reduces quiescent current below 120µA and maintains high efficiency at light loads. An internal high voltage bias regulator allows for simple biasing.

Additional features include current mode control for fast line and load transient response; programmable fixed operating frequency that can be synchronized to an external clock for noise sensitive applications; a gate driver capable of driving large N-channel MOSFETs; a precision undervoltage lockout function; 10µA shutdown current; short-circuit protection and a programmable soft-start function.

The LT3844 is available in a 16-lead thermally enhanced TSSOP package.