AN2785 datasheet(9/51 Pages) STMICROELECTRONICS

Part #	AN2785

Description	L6393 half bridge gate driver

PDF	51 Pages

Scroll/Zoom	100%

Manufacturer	STMICROELECTRONICS [STMicroelectronics]

Direct Link	http://www.st.com

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9 / 51 page

AN2785

Dead time function

Doc ID 14785 Rev 1

9/51

Dead time function

To avoid any possible cross-conduction between the power MOSFETs/IGBTs of the half

bridge, the L6393 provides a dead time. The dead time function is a safety time introduced

by the device between the falling edge transition of one driver output and the rising edge of

the other output. The dead time can be adjusted externally through the value of the DT

resistor connected between pin 5 and pin 7

as indicated in Figure 5. A 100 nF ceramic

capacitor in parallel to this resistor is recommended for noise immunity. Figure 4 provides

details of the dead time.

Figure 4.

Timing waveforms

Figure 5.

Typical dead time vs DT resistor value

LVG

HVG

PHASE

BRAKE

DTLH

DTHL

DTLH

0.5

1.5

2.5

3.5

100

150

200

250

300

Rdt (kOhm)

AN2785 Datasheet(PDF) 9 Page - STMicroelectronics