L6725_07 STMICROELECTRONICS [STMicroelectronics], L6725_07 Datasheet - Page 13

• Manufacturer Part Number: L6725_07
• Description: Voltage mode PWM controller with bootstrap anti-discharging system
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

L6725 - L6725A
Figure 6.
Figure 7.
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
the programmed value. No switching activity is observable if V
MOSFETs are OFF. When V
As V
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
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
reaches 3.5V. After that the over-current-protection triggers the HICCUP mode.
Start-up without pre-bias
Start-up with pre-bias
SS
reaches 1.1V (i.e. the oscillator triangular wave inferior limit) even the high-side
SS
is between 0.5V and 1.1V the low-side MOSFET is turned ON.
14). The soft-start phase ends when Vss
SS
is lower than 0.5V and both
LGate
V
Figure 6.
V
I
SS
V
LGate
OUT
L
V
OUT
SS
I
L
Device description
and
Figure
13/32
7.).