L6362A datasheet(25/37 Pages) STMICROELECTRONICS

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L6362A

Slow demagnetization

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Slow demagnetization

Slow demagnetization is also known as synchronous rectification or slow current decay and

it is active in push pull mode. When a high-side driver turns off an inductance, a reversed

polarity voltage appears across the load. In push-pull configuration the low-side switch is

ON and the OUTH pin is pulled at a voltage slightly (depending on the low-side switch

drop) below the ground. The energy is dissipated in both IC internal switch and load

resistance. Similarly, in case of load connected between the OUTL pin and VCC, at the

switch-off of the low-side switch, the HS switch is ON and the output is pushed to a voltage

slightly higher than VCC. Slow demagnetization is always active in PP configurations: the

diodes of the integrated switches activate the slow demagnetization even when the IC is

driven by EN/DIAG instead of IN2. See Table 14: "Output stage truth table" for the detailed

behavior of the power stage in different configurations and conditions.

Figure 10: Slow demagnetization principle operation. (PP, load to GND)

Figure 11: Slow demagnetization operation example. HS configuration (load to GND)

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