L6730 datasheet(20/52 Pages) STMICROELECTRONICS

部件名	L6730

功能描述	Adjustable step-down controller with synchronous rectification

PDF	52 Pages

Scroll/Zoom	100%

制造商	STMICROELECTRONICS [STMicroelectronics]

网页	http://www.st.com

标志

20 / 52 page

Device description

L6730 - L6730B

20/52

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 12.).

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 (–350mV 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 negative. This

situation happens when the converter is sinking current for example and, in this case, an

adaptive dead time control operates.

Figure 12. Dead times

L6730 数据表(PDF) 20 Page - STMicroelectronics