Features

• Input Voltage Range: 2.5V to 18V
• Runs Down to V_IN = 250mV After Start-Up
• Output Voltage Range: 0.8V to 18V
• 5A Output Current in Buck Mode, V_IN > 6V
• 3A Output Current for V_IN = 3.6V, V_OUT = 5V
• Programmable Switching Frequency: 400kHz to 2MHz
• Synchronizable with an External Clock Up to 2MHz
• Accurate Run Comparator Threshold
• Burst Mode® Operation, No-Load I_Q = 35μA
• Ultralow Noise Buck-Boost PWM
• Current Mode Control
• Maximum Power Point Control
• Power Good Indicator
• Internal Soft-Start
• 28-Lead 4mm × 5mm QFN and TSSOP Packages

Typical Application

Description

The LTC®3119 is a high efficiency 18V monolithic buck-boost converter that can deliver up to 5A of continuous output current. Extensive feature integration and very low resistance internal power switches minimize the total solution footprint for even the most demanding applications. A proprietary 4-switch PWM architecture provides seamless low noise operation from input voltages above, equal to, or below the output voltage.

External frequency programming as well as synchronization using an internal PLL enable operation over a wide switching frequency range of 400kHz to 2MHz. The wide 2.5V to 18V input range is well suited for operation from unregulated power sources including battery stacks and backup capacitors. After start-up, operation is possible with input voltages as low as 250mV.

Other features include: output short-circuit protection, thermal overload protection, less than 3μA shutdown current, power good indicator, Burst Mode operation, and maximum power point control.

The LTC3119 is offered in thermally enhanced 28-lead 4mm × 5mm QFN and TSSOP packages.