L6730 datasheet(25/52 Pages) STMICROELECTRONICS

部品番号	L6730

部品情報	Adjustable step-down controller with synchronous rectification

PDF	52 Pages

Scroll/Zoom	100%

メーカー	STMICROELECTRONICS [STMicroelectronics]

ホームページ	http://www.st.com

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25 / 52 page

L6730 - L6730B

Device description

25/52

Using the L6730B there is the possibility to set the constant-current-protection also after the

soft-start. The following figures show the behaviour of the L6730B during an overcurrent event.

Figure 19. shows the intervention of the peak OCP: the high-side MOSFET(s) is turned-off

when the current exceeds the OCP threshold. In this way the duty-cycle is reduced, the VOUT is

reduced and so the maximum current can be fixed even if the output current is escalating.

Figure 20. shows the limit of this protection: the on-time can be reduced only to the masking

time and, if the output current continues to increase, the maximum current can increase too.

Notice how the Vout remains constant even if the output current increases because the on-time

cannot be reduced anymore.

Figure 19. Peak overcurrent-protection in constant-current-protection (L6730B).

Figure 20. Peak OCP in case of heavy overcurrent (L6730B).

VOUT

TON

IOUT

Peak th

VOUT

IOUT

L6730 データシート(PDF) 25 Page - STMicroelectronics