LM5119 Dual Synchronous Buck Controller

Texas Instruments' 65V dual-channel, dual-phase synchronous buck controller saves PCB space in high voltage applications

image of Texas Instruments' LM5119 Dual Synchronous Buck ControllerTexas Instruments' LM5119 is a dual synchronous buck controller intended for step-down regulator applications from a high voltage or widely varying input supply. The control method is based upon current mode control utilizing an emulated current ramp. Current mode control provides inherent line feed-forward, cycle-by-cycle current limiting and ease of loop compensation. The use of an emulated control ramp reduces noise sensitivity of the pulse-width modulation circuit, allowing reliable control of very small duty cycles necessary in high input voltage applications. The switching frequency is programmable from 50 kHz to 750 kHz. The LM5119 drives external high-side and low-side NMOS power switches with adaptive dead-time control. A user-selectable diode emulation mode enables discontinuous mode operation for improved efficiency at light load conditions. A high voltage bias regulator with automatic switchover to external bias further improves efficiency. Additional features include thermal shutdown, frequency synchronization, cycle-by-cycle and hiccup mode current limit, and adjustable line undervoltage lockout. The device is available in a power enhanced leadless LLP-32 package that features an exposed die attach pad to aid thermal dissipation.

Features
  • Emulated peak current mode control
  • Wide operating range from 5.5 V to 65 V
  • Easily configurable for dual outputs or interleaved single output
  • Robust 3.3 A peak gate drive
  • Switching frequency programmable to 750 kHz
  • Optional diode emulation mode
  • Programmable output from 0.8 V
  • Precision 1.5% voltage reference
  • Programmable current limit
  • Hiccup mode overload protection
  • Programmable soft-start
  • Programmable line undervoltage lockout
  • Automatic switchover to external bias supply
  • Channel2 enable logic input
  • Thermal shutdown
  • Leadless LLP32 (5 mm x 5 mm) package

Buck Controller

ImageManufacturer Part NumberDescriptionAvailable Quantity
LM5119PSQE/NOPB datasheet linkIC REG CTRLR BUCK 32WQFNLM5119PSQE/NOPBIC REG CTRLR BUCK 32WQFN971 - Immediate
500 - Factory Stock
LM5119PSQE/NOPB product page link

Evaluation Board

ImageManufacturer Part NumberDescriptionAvailable Quantity
LM5119EVAL/NOPB datasheet linkBOARD EVALUATION LM5119LM5119EVAL/NOPBBOARD EVALUATION LM51193 - Immediate
29 - Factory Stock
LM5119EVAL/NOPB product page link
Published: 2010-11-26