LM2611

LM2611 1.4MHz Cuk Converter January 2002 LM2611 1.4MHz Cuk Converter General Description The LM2611 is a current mode, PWM inverting switching regulator. Operating from a 2.7 - 14V supply, it is capable of producing a regulated negative output voltage of up to −(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 1.4MHz, 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 is a small SOT23-5 package. It comes in two grades: Grade A Current Limit RDS(ON) 1.2A 0.5Ω Grade B 0.9A 0.7Ω Features n n n n n n n n n 1.4MHz switching frequency Low RDS(ON) DMOS FET 1mVp-p output ripple −5V at 300mA from 5V input Better regulation than a charge pump Uses tiny capacitors and inductors Wide input range: 2.7V to 14V Low shutdown current: < 1uA 5-lead SOT-23 package Applications n n n n n MR Head Bias Digital camera CCD bias LCD bias GaAs FET bias Positive to negative conversion Typical Application Circuit 20018117 © 2002 Na...