Features

• Wide Operating V_IN Range: 3.5V to 60V
• Wide Negative V_OUT Range: –0.4V to Beyond –150V
• Low Operating I_Q = 70μA
• Strong High Voltage MOSFET Gate Driver
• Constant Frequency Current Mode Architecture
• Verified FMEA for Adjacent Pin Open/Short
• Selectable High Efficiency Burst Mode® Operation or Pulse-Skipping Mode at Light Loads
• Programmable Fixed Frequency: 50kHz to 850kHz
• Phase-Lockable Frequency: 75kHz to 750kHz
• Accurate Current Limit
• Programmable Soft-Start or Voltage Tracking
• Internal Soft-Start Guarantees Smooth Start-Up
• Low Shutdown I_Q = 7μA
• Available in Small 12-Lead Thermally Enhanced MSOP and DFN Packages

Typical Application

Description

The LTC®3863 is a robust, inverting DC/DC PMOS controller optimized for automotive and industrial applications. It drives a P-channel power MOSFET to generate a negative output and requires just a single inductor to complete the circuit. Output voltages from –0.4V to –150V are typically achievable with higher voltages possible, only limited by external components.

The LTC3863 offers excellent light load efficiency, drawing only 70μA quiescent current in a user programmable Burst Mode operation. Its peak current mode, constant frequency PWM architecture provides for good control of switching frequency and output current limit. The switching frequency can be programmed from 50kHz to 850kHz with an external resistor and can be synchronized to an external clock from 75kHz to 750kHz.

The LTC3863 offers programmable soft-start or output tracking. Safety features include overvoltage, overcurrent and short-circuit protection including frequency foldback.

The LTC3863 is available in thermally enhanced 12-lead MSOP and 3mm × 4mm DFN packages.