The LM2831 regulator is a monolithic, high-frequency, PWM step-down DC/DC converter in a 5-pin SOT23 and 6-pin LLP package. It provides all the active functionality to provide fast transient response and precisely tuned local DC/DC conversion in the smallest possible PCB area.
The LM2831 has minimal external components and is easy to use. Optimal power density is achieved with the ability to drive 1.5A loads with an internal 130 mΩ PMOS switch, using state-of-the-art 0.5µm BiCMOS technology. World class control circuits allow turn-on times as low as 30ns, thus supporting abnormally high frequency conversion throughout the 3V to 5.5V input operating range, up to a minimum output voltage of 0.6V.
The switching frequency is set internally to 550 kHz, 1.6 MHz or 3.0 MHz, allowing the use of extremely small surface mount inductors and chip capacitors. Even with high frequency, efficiency can easily reach 93%. Including external shutdown, with ultra low standby current of 30 nA. The LM2831 utilizes current mode control and internal compensation to provide high performance conditioning in a wide range of operating conditions. Other features include internal soft-start circuitry to reduce inrush current, pulse-to-pulse current limitation, thermal shutdown and output overvoltage protection.
Simplified Block Diagram
