AN938 Datasheet, PDF (15/33 Pages) STMicroelectronics – The L4973 family is a 3.5 A monolithic DC-DC converter

AN938
Power supply, UVLO and voltage reference
Figure 19. Power stage internal circuit
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The L4973 has been developed with a special focus on this dynamic area.
An innovative and proprietary gate driver with two different timings has been introduced.
When the diode reverse voltage reaches about 3 V, the gate is sourced with low current (see
Figure 18) to assure the complete recovery of the diode without generating unwanted extra
peak currents and noise.
After this threshold, the gate drive current is quickly increased, producing a fast rise time to
reach a high efficiency.
Figure 20. Sync and oscillator waveforms as slave and as master
Doc ID 5410 Rev 10
AM03502v1
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