LM2586 datasheet(20/38 Pages) TI

20 / 38 page

LM2586

SNVS121D – MAY 1996 – REVISED APRIL 2013

www.ti.com

Step-Up (Boost) Regulator Operation

Figure 46 shows the LM2586 used as a step-up (boost) regulator. This is a switching regulator that produces an

output voltage greater than the input supply voltage.

A brief explanation of how the LM2586 Boost Regulator works is as follows (refer to Figure 46). When the NPN

switch turns on, the inductor current ramps up at the rate of VIN/L, storing energy in the inductor. When the

switch turns off, the lower end of the inductor flies above VIN, discharging its current through diode (D) into the

output capacitor (COUT) at a rate of (VOUT − VIN)/L. Thus, energy stored in the inductor during the switch on time

is transferred to the output during the switch off time. The output voltage is controlled by adjusting the peak

switch current, as described in Flyback Regulator.

Figure 46. 12V Boost Regulator

By adding a small number of external components (as shown in Figure 46), the LM2586 can be used to produce

a regulated output voltage that is greater than the applied input voltage. The switching waveforms observed

during the operation of this circuit are shown in Figure 47. Typical performance of this regulator is shown in

Figure 48.

Submit Documentation Feedback

Product Folder Links: LM2586

LM2586 Datasheet(PDF) 20 Page - Texas Instruments