L6713A
Load transient boost technologyTM
13 Load transient boost technologyTM
Load transient boost LTB Technology™ (patent pending) is a L6713A feature to minimize
the count of output filter capacitors (MLCC and bulk capacitors) to respect the load transient
specifications.
The device turns on simultaneously all the phases as soon as a load transient is detected
and keep them on for the necessary time to supply the extra energy to the load. This time
depends on the COMP pin voltage and on a internal gain, in order to keep under control the
output voltage ring back.
Load transition is detected through LTB™ pin connecting a RLTB-CLTB vs. VOUT: the device
measures the derivate dV/dt of the output voltage and so it is able to turns on all the phases
immediately after a load transition detection, minimizing the delay intervention.
Modifying the RLTB-CLTB values the dV/dt can be easily programmed, extending the system
design flexibility
RLTB
=
-d---V----O----U----T-
50μA
CLTB
=
--------------------------1----------------------------
2 ⋅ π ⋅ RLTB ⋅ N ⋅ FSW
where dVOUT is the output voltage drop due to load transition.
Moreover, load transient boost LTB Technology™ gain can be easily modified in order to
keep under control the output voltage ring back.
Figure 12. LTB connections (left) and waveform (right)
LTB
To VCC_Core
RLTB
CLTB
Short LTB pin to SGND to disable the LTB Technology™: in this condition the device works
as a dual-edge asynchronous PWM controller.
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