The LM5116 is a 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
using 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 operating frequency is
programmable from 50 kHz to 1 MHz. The LM5116 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 low quiescent current shutdown disables the controller and
consumes less than 10 µA of total input current.
Additional features include a
high-voltage bias regulator, automatic switch-over to external bias for improved
efficiency, thermal shutdown, frequency synchronization, cycle-by-cycle current
limit, and adjustable line undervoltage lockout. The device is available in a power
enhanced HTSSOP-20 package featuring an exposed die attach pad to aid thermal
dissipation.
New products (LM5148 and LM5149) offer reduced BOM cost, higher
efficiency, and reduced design size among many other features.
The LM5116 is a 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
using 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 operating frequency is
programmable from 50 kHz to 1 MHz. The LM5116 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 low quiescent current shutdown disables the controller and
consumes less than 10 µA of total input current.
Additional features include a
high-voltage bias regulator, automatic switch-over to external bias for improved
efficiency, thermal shutdown, frequency synchronization, cycle-by-cycle current
limit, and adjustable line undervoltage lockout. The device is available in a power
enhanced HTSSOP-20 package featuring an exposed die attach pad to aid thermal
dissipation.
New products (LM5148 and LM5149) offer reduced BOM cost, higher
efficiency, and reduced design size among many other features.