1 Features

1? 1.4-MHz Switching Frequency

? Low R DS(ON) DMOS FET

? 1-mVp-p Output Ripple

? ?5 V at 300 mA From 5-V Input

? Better Regulation Than a Charge Pump

? Uses Tiny Capacitors and Inductors

? Wide Input Range: 2.7 V to 14 V

? Low Shutdown Current: <1 μA

? 5-Pin SOT-23 Package

2 Applications

? MR Head Bias

? Digital Camera CCD Bias

? LCD Bias

? GaAs FET Bias

? Positive to Negative Conversion

3 Description

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 ?(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).