FEATURES

? Emulated Peak Current Mode

? Wide Operating Range Up to 80 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 Under-Voltage Lockout

? Automatic Switch to External Bias Supply

SUPPORTS EXTREME TEMPERATURE

APPLICATIONS

? Controlled Baseline

? One Assembly and Test Site

? One Fabrication Site

? Available in Extreme (–55°C to 175°C)

Temperature Range

? Extended Product Life Cycle

? Extended Product-Change Notification

? Product Traceability

? Texas Instruments' high temperature products

utilize highly optimized silicon (die) solutions with design and process enhancements to

maximize performance over extended

temperatures.

APPLICATIONS

? Down-Hole Drilling

? High Temperature Environments

DESCRIPTION

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 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 LM5116 drives external high-side and lowside

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 under-voltage lockout.