90V to 10V @ 500mA High Voltage DC-DC buck converter

  • Rajkumar Sharma
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This is a versatile tiny module that provides 10V/500mA from 90V DC input. It is a high voltage input DC-DC buck converter, based on LM5017 IC, which is a 100-V, 600-mA synchronous step-down regulator with integrated high side and low side MOSFETs. The constant on-time (COT) control scheme employed in the LM5017 requires no loop compensation, provides an excellent transient response, and enables very high step-down ratios. The ON-time varies inversely with the input voltage resulting in nearly constant frequency over the input voltage range. A high voltage startup regulator provides bias power for the internal operation of the IC and for integrated gate drivers. A peak current limit circuit protects against overload conditions. The under-voltage lockout (UVLO) circuit allows the input under-voltage threshold and hysteresis to be independently programmed. Other protection features include thermal shutdown and bias supply under-voltage lockout (VCC UVLO). Supply input range 13V to 90V, provides 10V/500mA, switching frequency 225 KHz. Adjustable output voltage possible by altering Resistor R6 and R8 value, refer data sheet. Under-Voltage lockout set to 12.4V.

Features

  • Wide 13V to 90V Input Range
  • Output 10V 500MA (Adjustable Output Voltage from 1.225 V)
  • Integrated 100-V High-Side, and Low-Side Switches
  • Constant On-Time Control
  • No Loop Compensation Required
  • Ultra-Fast Transient Response
  • Nearly Constant Operating Frequency
  • Intelligent Peak Current Limit
  • Precision 2% Feedback Reference
  • Frequency 225Khz (Adjustable to 1 MHz)
  • Adjustable Under voltage Lockout (UVLO) (Set to 12.4V)
  • Thermal Shutdown
  • PCB Dimensions 25.44 x 12.05 mm

Schematic

Parts List

Connections



Photos

LM5017 Datasheet

lm5017

PCB

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