Features

• Wide Input Range:
      Operation from 3.6V to 36V
      Overvoltage Lockout Protects Circuits
      Through 60V Transients
• FMEA Fault Tolerant:
      Output Stays at or Below Regulation Voltage
      During Adjacent Pin Short or When a Pin Is Left Floating
• 1A Output Current
• Low Ripple (< 15mV_P-P) Burst Mode® Operation
       I_Q = 75μA for 12VIN to 3.3V_OUT with No Load
• Adjustable Switching Frequency: 250kHz to 2.2MHz
• Short-Circuit Protected
• Synchronizable Between 300kHz and 2.2MHz
• Output Voltage: 0.8V to 20V
• Power Good Flag
• Fixed Output Voltage Versions for 3.3V and 5V Available Small, Thermally Enhanced 16-Pin MSOP Package

Typical Application

Description

The LT3695 series are adjustable frequency (250kHz to 2.2MHz) monolithic buck switching regulators that accept input voltages up to 36V and can safely sustain transient voltages up to 60V. The devices include a high efficiency switch, a boost diode, and the necessary oscillator, control and logic circuitry. Current mode topology is used for fast transient response and good loop stability. A SYNC pin allows the user to synchronize the part to an external clock, and to choose between low ripple Burst Mode operation and standard PWM operation.

The LT3695 regulators tolerate adjacent pin shorts or an open pin without raising the output voltage above its programmed value.

Low ripple Burst Mode operation maintains high efficiency at low output currents while keeping output ripple below 15mV in a typical application. Shutdown reduces input supply current to less than 1μA while a resistor and capacitor on the RUN/SS pin provide a controlled output voltage ramp (soft-start). Protection circuitry senses the current in the power switch and external Schottky catch diode to protect the LT3695 regulators against short-circuit conditions. Frequency foldback and thermal shutdown provide additional protection.

The LT3695 series is available in a thermally enhanced 16-pin MSOP package.