L9959T datasheet(22/43 Pages) STMICROELECTRONICS

Part #	L9959T

Description	Single and dual PMOS high-side H-bridge

PDF	43 Pages

Scroll/Zoom	100%

Manufacturer	STMICROELECTRONICS [STMicroelectronics]

Direct Link	http://www.st.com

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22 / 43 page

Application information

L9959S, L9959T

22/43

DocID023416 Rev 6

Figure 10. PWM mode output voltage

During PWM mode the high-side (e.g. Figure 9 HS1) output is switched off with a slow slew

rate until it is off and the low-side body-diode has taken over the entire current. Then the

associated low-side transistor (e.g. Figure 9 LS1) is turned on with a fast slope to reduce the

voltage across the device and to minimize the power.

The output is pulled to high voltage, by first turning off the low-side driver with a fast slew

rate and, after it is off, the high-side driver is switched on by a slow one (e.g. Figure 9 LS1,

HS1).

This assures, that the voltage and current change over the body diode is done smoothly,

reducing the electromagnetic emission.

Figure 11. DIR-change (current is changing its direction)

Figure 12. DIR-change current flow phase 2

L9959T Datasheet(PDF) 22 Page - STMicroelectronics