AN4192 datasheet(11/47 Pages) STMICROELECTRONICS

Part #	AN4192

Description	In the latest generation of CPUs for modern desktop and notebook platforms

PDF	47 Pages

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Manufacturer	STMICROELECTRONICS [STMicroelectronics]

Direct Link	http://www.st.com

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11 / 47 page

AN4192

High-side MOSFET selection

Doc ID 023820 Rev 1

11/47

Figure 6.

Efficiency comparison @ 440 kHz

As can be clearly seen, the high-side 2 has the best efficiency in the whole current range,

because of the switching loss minimization (see (1)).

Now, let's consider the converter performance, with the same MOSFET configurations, at

two different switching frequencies: 300 kHz and 440 kHz. Increasing fSW, the converter

efficiency decreases, as some power losses increase with the frequency (switching losses,

HS/LS gate drive and LS reverse recovery losses, etc.…). Furthermore, the importance of a

high switching speed rises when the switching frequency increases. In Figure 6 and

Figure 7, the efficiency curves at 300 kHz and 440 kHz are illustrated.

Figure 7.

Efficiency @ 300 kHz

Table 1.

HS FETs electrical parameters comparison

BV [V]

RDS(on) [mΩ]Qg,SW [nC]

High-side 1

9.2 / 10.5

6.85

High-side 2

7.3 / 8.3

4.65

High-side 3

7.6 / 9.5

9.25

High-side 4

7.0 / 9.0

AM16450V1

AM16451V1

AN4192 Datasheet(PDF) 11 Page - STMicroelectronics