The LM5118 wide
voltage range Buck-Boost switching regulator controller features all of the functions necessary to
implement a high-performance, cost-efficient Buck-Boost regulator using a minimum of external
components. The Buck-Boost topology maintains output voltage regulation when the input voltage is
either less than or greater than the output voltage, making it especially suitable for automotive
applications. The LM5118
operates as a buck regulator while the input voltage is sufficiently greater than the regulated
output voltage and gradually transitions to the buck-boost mode as the input voltage approaches the
output. This dual-mode approach maintains regulation over a wide range of input voltages with
optimal conversion efficiency in the buck mode and a glitch-free output during mode transitions.
This easy-to-use controller includes drivers for the high-side buck MOSFET and the low-side boost
MOSFET. The regulators control method is based upon current mode control using an emulated current
ramp. Emulated current mode control reduces noise sensitivity of the pulse-width modulation
circuit, allowing reliable control of the very small duty cycles necessary in high input voltage
applications. Additional protection features include current limit, thermal shutdown and an enable
input. The device is available in a power-enhanced, 20-pin HTSSOP package featuring an exposed die
attach pad to aid thermal dissipation.
The LM5118 wide
voltage range Buck-Boost switching regulator controller features all of the functions necessary to
implement a high-performance, cost-efficient Buck-Boost regulator using a minimum of external
components. The Buck-Boost topology maintains output voltage regulation when the input voltage is
either less than or greater than the output voltage, making it especially suitable for automotive
applications. The LM5118
operates as a buck regulator while the input voltage is sufficiently greater than the regulated
output voltage and gradually transitions to the buck-boost mode as the input voltage approaches the
output. This dual-mode approach maintains regulation over a wide range of input voltages with
optimal conversion efficiency in the buck mode and a glitch-free output during mode transitions.
This easy-to-use controller includes drivers for the high-side buck MOSFET and the low-side boost
MOSFET. The regulators control method is based upon current mode control using an emulated current
ramp. Emulated current mode control reduces noise sensitivity of the pulse-width modulation
circuit, allowing reliable control of the very small duty cycles necessary in high input voltage
applications. Additional protection features include current limit, thermal shutdown and an enable
input. The device is available in a power-enhanced, 20-pin HTSSOP package featuring an exposed die
attach pad to aid thermal dissipation.