A5975AD datasheet(28/50 Pages) STMICROELECTRONICS

Numer części	A5975AD

Szczegółowy opis	Voltage feed-forward

PDF	50 Pages

Scroll/Zoom	100%

Producent	STMICROELECTRONICS [STMicroelectronics]

Strona internetowa	http://www.st.com

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Application information

A5975AD

28/50

Doc ID 018761 Rev 1

Switching losses due to turning on and off. These are derived using the following

equation:

Equation 24

where TRISE and TFALL represent the switching times of the power element that cause the

switching losses when driving an inductive load (see Figure 14). TSW is the equivalent

switching time.

Figure 14.

Switching losses

Quiescent current losses.

Equation 25

where IQ is the quiescent current.

Example:

–VIN = 12 V

–VOUT = 3.3 V

–IOUT = 2.5 A

RDS(on) has a typical value of 0.25 @ 25 °C and increases up to a maximum value of 0.5. @

150 °C. We can consider a value of 0.4

Ω.

TSW is approximately 70 ns.

IQ has a typical value of 5 mA @ VIN = 12 V.

OUT

OFF

()

------------------------------------ F

OUT

⋅⋅

⋅

A5975AD Arkusz danych(PDF) 28 Page - STMicroelectronics