LM5017 datasheet(17/31 Pages) TI

17 / 31 page

VOUT2 = VOUT1 x

- VF

LM5017

www.ti.com

SNVS783I – JANUARY 2012 – REVISED OCTOBER 2015

8.2.1.3 Application Curves

Figure 14. Efficiency vs Load Current

Figure 15. Frequency vs Input Voltage

Figure 16. Typical Switching Waveform (Vin = 48 V, Iout = 200 mA)

8.2.2 Isolated DC-DC Converter Using LM5017

An isolated supply using LM5017 is shown in Figure 17. Inductor (L) in a typical buck circuit is replaced with a

coupled inductor (X1). A diode (D1) is used to rectify the voltage on a secondary output. The nominal voltage at

the secondary output (VOUT2) is given by Equation 20.

(20)

Where:

VF is the forward voltage drop of D1

NP and NS are the number of turns on the primary and secondary of coupled inductor X1.

For output voltage (VOUT1) more than one diode drop above the maximum VCC (8.55 V), the VCC pin can be diode

connected to VOUT1 for higher efficiency and low dissipation in the IC. See AN-2204 (SNVA611) for a complete

isolated bias design with LM5017.

Submit Documentation Feedback

Product Folder Links: LM5017

LM5017 Datasheet(PDF) 17 Page - Texas Instruments