L6730B datasheet(20/52 Pages) STMICROELECTRONICS

Nome de Peças	L6730B

Descrição Electrónicos	Adjustable step-down controller with synchronous rectification

PDF	52 Pages

Scroll/Zoom	100%

Fabricante Electrônico	STMICROELECTRONICS [STMicroelectronics]

Página de início	http://www.st.com

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20 / 52 page

Device description

L6730 - L6730B

20/52

Doc ID 11938 Rev 3

5.7

Driver section

The high-side and low-side drivers allow for the use of different types of power MOSFETs

(also multiple MOSFETs to reduce the RDSON), maintaining fast switching transitions. The

low-side driver is supplied by VCCDR while the high-side driver is supplied by the BOOT pin.

A predictive dead time control avoids MOSFETs cross-conduction maintaining very short

dead time duration (see Figure 13.).

The control monitors the phase node in order to sense the low-side body diode recirculation.

If the phase node voltage is less than a certain threshold (–350 mV typ.) during the dead

time, it will be reduced in the next PWM cycle. The predictive dead time control does not

work when the high-side body diode is conducting because the phase node does not go

Figure 12.

Sink mode disabled: Inductor current during and after soft-start (L6730)

Vout

Vss

Vcc

L6730B Folha de dados(PDF) 20 Page - STMicroelectronics