STMicroelectronics L6986I

The L6986I is a device specifically designed for the isolated buck topology. Due to the P-Channel MOSFET as high-side power switch the device features 100% duty cycle operation. The primary output voltage can be accurately adjusted, whereas the isolated secondary output is derived by using a given transformer ratio. No optocoupler is required. The primary sink capability up to 1.9 A (even during soft-start) allows a proper energy transfer to the secondary side as well as enables a tracked soft-start of the secondary output. The control loop is based on a peak current mode architecture and the device operates in forced PWM. 

Key features

• 4 V to 38 V operating input voltage
• 8 µA I_Q-SHTDWN
• Primary output voltage regulation / no optocoupler required
• 1.9 A typical sink peak primary current capability

Additional features

• Designed for iso-buck topology
• 4 V to 38 V operating input voltage
• Primary output voltage regulation / no optocoupler required
• 1.9 A typical sink peak primary current capability
• Peak current mode architecture in forced PWM operation
• 300 ns blanking time
• 8 µA I_Q-SHTDWN
• Adjustable f_SW and synchronization
• Embedded primary output voltage supervisor
• Adjustable soft-start time
• Internal primary current limiting
• Overvoltage protection
• R_DS(on) HS = 180 mΩ, R_DS(on) LS = 150 mΩ
• Thermal shutdown

Applications

• Isolated power supply for SiC MOSFET and IGBT drivers
• Isolated power supply for isolated interfaces (RS232, I2C, SPI, etc.)
• EV chargers
• Motor drivers
• Automation

Available Tools

• STEVAL-L6986IV1: 
  • 38 V, 5 W synchronous iso-buck converter evaluation board with dual isolated output based on the L6986I

Video

L6986I and A6986I 38V 5W synchronous iso-buck regulators