The LM2611 is a current mode, PWM inverting switching regulator. Operating from a 2.7-V to 4-V supply, it is capable of producing a regulated negative output voltage of up to &ndash(36 VIN(MAX)). The LM2611 utilizes an input and output inductor, which enables low voltage ripple and RMS current on both the input and the output. With a switching frequency of 1.4 MHz, the inductors and output capacitor can be physically small and low cost. High efficiency is achieved through the use of a low RDS(ON) FET.
The LM2611 features a shutdown pin, which can be activated when the part is not needed to lower the Iq and save battery life. A negative feedback (NFB) pin provides a simple method of setting the output voltage, using just two resistors. Cycle-by-cycle current limiting and internal compensation further simplify the use of the LM2611.
The LM2611 is available as a small 5-pin, SOT-23 package and comes in two grades. Grade A has a 1.2-A current limit and 0.5-Ω RDS(ON), and Grade B has a 0.9-A current limit and 0.7-Ω RDS(ON).