The LM5116MH is a synchronous buck controller intended for step-down regulator applicationsfrom a high-voltage or widely varying input supply. The control method is based upon current modecontrol utilizing an emulated current ramp. Current mode control provides inherent linefeed-forward, cycle-by-cycle current limiting, and ease-of-loop compensation. The use of anemulated control ramp reduces noise sensitivity of the pulse-width modulation circuit, allowingreliable control of very small duty cycles necessary in high-input voltage applications.
The operating frequency is programmable from 50 kHz to 1 MHz. The LM5116MH drives externalhigh-side and low-side NMOS power switches with adaptive dead-time control. A user-selectable diodeemulation mode enables discontinuous mode operation, for improved efficiency at light loadconditions. A low quiescent current shutdown disables the controller and consumes less than 10 μAof total input current.
Additional features include a high-voltage bias regulator, automatic switch-over toexternal bias for improved efficiency, thermal shutdown, frequency synchronization, cycle-by-cyclecurrent limit, and adjustable line undervoltage lockout. The device is available in a powerenhanced HTSSOP-20 package featuring an exposed die attach pad to aid thermal dissipation.
Feature
- Emulated Peak Current Mode
- Wide Operating Range Up to 100 V
- Low IQ Shutdown (< 10 μA)
- Drives Standard or Logic Level MOSFETs
- Robust 3.5-A Peak Gate Drive
- Free-run or Synchronous Operation to 1 MHz
- Optional Diode Emulation Mode
- Programmable Output from 1.215 V to 80 V
- Precision 1.5% Voltage Reference
- Programmable Current Limit
- Programmable Soft-Start
- Programmable Line Undervoltage Lockout
- Automatic Switch to External Bias Supply
- HTSSOP-20 Exposed Pad
- Thermal Shutdown
- Create a Custom Design Using the LM5116 with the WEBENCH Power Designer
