Features

• Wide Input Range: 5V to 42V
• Low Dropout Under All Conditions: 450mV at 2.1A
• Accurate 5V Output: ±1.3% Over Full Temperature Range
• Programmable Cable Drop Compensation
• Programmable Output Current Limit
• Output Current Monitor
• Dual Input Feedback Permits Regulation on Output of USB Switch
• Forced Continuous Mode for Fast Load Step Response
• High Efficiency Synchronous Operation at 2MHz:
  93% Efficiency at 2.1A, 5V_OUT from 12V_IN
  95% Efficiency at 0.9A, 5V_OUT from 12V_IN
• Fast Minimum Switch-On Time: 45ns
• Adjustable Output from 5.0V to 5.25V
• Adjustable and Synchronizable: 300kHz to 2.2MHz
• Small Thermally Enhanced 3mm × 5mm 24-Lead QFN Package

Typical Application

Description

The LT®8697 is a compact, high efficiency, high speed synchronous monolithic step-down switching regulator designed to power 5V USB applications. A precise output voltage and programmable cable drop compensation maintain accurate 5V regulation at the USB socket connected to the end of a long cable. Forced continuous operation allows the LT8697 to sink current, further enhancing accurate 5V regulation during load transients.

Accurate and programmable output current limit, a power good indicator pin and an output current monitor pin improve system reliability and safety, allow the user to implement latch-off or auto-retry functionality and can eliminate the need for a USB switch IC. Dual feedback allows regulation on the output of a USB switch and limits cable drop compensation to a maximum of 5.8V output, protecting USB devices during fault conditions. Thermal shutdown provides additional protection by limiting power dissipation in the IC during an overtemperature fault.

The LT8697 is available in a small 24-lead 3mm × 5mm package with an exposed pad for low thermal resistance.