1FEATURES
2• Hermetic Package for Harsh Operating
Environments
• Emulated Peak Current Mode
• Wide Operating Range up to 100V
• Low I Q Shutdown (< 10 μA)
• Drives Standard or Logic Level MOSFETs
• Robust 3.5A Peak Gate Drive
• Free-Run or Synchronous Operation to 1 MHz
• Optional Diode Emulation Mode
• Programmable Output from 1.215V to 80V
• Precision 1.5% Voltage Reference dead•
Programmable Current Limit
• Programmable Soft-Start
• Programmable Line Under-Voltage Lockout
• Automatic Switch to External Bias Supply
• CPGA-20 with No Thermal Shutdown

DESCRIPTION
The LM5116WG 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
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 operating frequency is programmable from 50 kHz to
1 MHz. The LM5116WG 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, frequency synchronization, cycle
by cycle current limit and adjustable line undervoltage
lockout. The device is available in a CPGA-20
high temperature ceramic package with the thermal
shutdown feature disabled.