L6714 STMicroelectronics, L6714 Datasheet - Page 50

• Manufacturer Part Number: L6714
• Description: IC CTRLR 4PH W/DRIVERS 64-TQFP
• Manufacturer: STMicroelectronics

Specifications of L6714

• Applications: Controller, Intel VR10, VR11, AMD CPU
• Voltage - Input: 12V
• Number Of Outputs: 4
• Voltage - Output: 0.3 ~ 1.6 V
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 64-TQFP Exposed Pad, 64-eTQFP, 64-HTQFP, 64-VQFP
• Mounting Style: SMD/SMT
• Case: QFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Over current protection
18
50/70
Over current protection
Depending on the current reading method selected, the device limits the peak or the bottom
of the inductor current entering in constant current until setting UVP as below explained.
The Over Current threshold has to be programmed, by designing the Rg resistors, to a safe
value, in order to be sure that the device doesn't enter OCP during normal operation of the
device. This value must take into consideration also the extra current needed during the
Dynamic VID Transition I
inductor DCR, the process spread and temperature variations of these sensing elements.
Moreover, since also the internal threshold spreads, the Rg design has to consider the
minimum value I
where I
Quasi-Constant-Current. I
current value I
implemented) considering that the device performs Track & Hold only for the LS sense
mode:
where I
Current, I
required by D-VID (when applicable) and N the number of phases. In particular, since the
device limits the peak or the valley of the inductor current (according to DAC/CS_SEL
status), the ripple entity, when not negligible, impacts on the real OC threshold value and
must be considered.
OCPx
OUT(OCP)
PP
is the inductor current ripple in each phase I
is the current measured by the current reading circuitry when the device enters
OUT(OCP)
I
OCPx
OCTH(min)
is still the output current value at which the device enters Quasi-Constant-
=
as follow (I
D-VID
I
-------------------------- -
I
-------------------------- -
OUT OCP
OUT OCP
of the threshold as follow:
OCPx
N
N
and, since the device reads across MOSFET R
Rg
must be calculated starting from the corresponding output
D-VID
=
–
+
----------- -
I
-----------------------------------------------------------------------
----------- -
OCPx max
I
I
2
2
PP
PP
must also be considered when D-VID are
+
+
I
----------------- -
I
----------------- -
D VID
D VID
I
OCTH min
–
–
N
N
R
SENSE max
LowSideMosfetSense
InductorDCRSense
D-VID
is the additional current
dsON
or
L6714