The LM5116 is said to be the industry’s first 6 to 100V current-mode buck controller for use in telecommunications, automotive and industrial control applications. Developed by National Semiconductor, it features a unique combination of high performance, flexibility and ease-of-use for dc/dc power supply designs.
The LM5116 is well-suited for step-down regulator applications from a high voltage or widely varying input supply. The current mode control utilizing National’s patented emulated current-mode (ECM) technology reduces noise sensitivity of the pulse-width modulation (PWM) circuit. It enables reliable control of very small duty cycles necessary in high input voltage applications. Additional features include thermal shutdown, programmable soft-start, frequency synchronization, cycle-by-cycle current limit and adjustable line under voltage lockout (UVLO).
The LM5116 has an ultra-wide input range up to 100V, with a programmable output range from 1.215V to 80V. The reduced noise sensitivity of the PWM control circuit allows reliable operation with very small duty cycles necessary in high input voltage applications. The emulated current ramp enables the LM5116 to exceed a 20:1 Vin:Vout step-down ratio when operating at 500 kHz. The operating frequency is user-programmable up to 1 MHz with the capability to synchronize switching to an external clock signal. A low quiescent-current sleep mode disables the controller and consumes only 10 microamps of total input current for minimal off-state drain in battery-powered applications.
National Semiconductor, www.national.com
