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SLOW DECAY MODE

Figure 11 shows the operation of the bridge in the Slow Decay mode. At the start of the off time, the lower power

MOS is switched off and the current recirculates around the upper half of the bridge. Since the voltage across

the coil is low, the current decays slowly. After the dead time the upper power MOS is operated in the synchro-

nous rectification mode. When the monostable times out, the lower power MOS is turned on again after some

delay set by the dead time to prevent cross conduction.

Figure 11. Slow Decay Mode Output Stage Configurations

0.1

1

10

100

1

10

100

Coff [nF]

1.5

µs (typ. value)

A) ON TIME

B) 1

µs DEAD TIME

C) SYNCHRONOUS

RECTIFICATION

D) 1

µs DEAD TIME

D01IN1336