L6725 - L6725A

Device description

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L6725:The output of the error amplifier is clamped with this voltage (VSS) until it reaches the

programmed value.

L6725A:The reference of the error amplifier is clamped with this voltage (VSS) until it reaches

MOSFET begins to switch and the output voltage starts to increase. During the soft-start phase

the current can’t be reversed in order to allow pre-biased start-up (see Figure 6. and Figure 7.)

.

If an over current is detected during the soft-start phase, the device provides a constant-

current-protection. In this way, in case of short soft-start time and/or small inductor value and/or

high output capacitors value, the converter can start in any case, limiting the current

(Chapter 5.8: Monitoring and protections on page 14). The soft-start phase ends when Vss

reaches 3.5V. After that the over-current-protection triggers the HICCUP mode.

Figure 6.

Start-up without pre-bias

Figure 7.

Start-up with pre-bias

LGate

LGate