L6714 STMicroelectronics, L6714 Datasheet - Page 61

• 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

L6714
23
23.1
Tolerance band (TOB) definition
Output voltage load-line varies considering component process variation, system
temperature extremes, and age degradation limits. Moreover, individual tolerance of the
components also varies among designs: it is then possible to define a Manufacturing
Tolerance Band (TOB
nominal load line characteristic.
TOB
Current Sense Circuit Tolerance and Time Constant Matching Error Tolerance. All these
parameters can be composed thanks to the RSS analysis so that the manufacturing
variation on TOB results to be:
Output voltage ripple (V
added to the Manufacturing TOB in order to get the system Tolerance Band as follow:
All the component spreads and variations are usually considered at 3 . Here follows an
explanation on how to calculate these parameters for a reference L6714 application.
Controller tolerance (TOB controller)
It can be further sliced as follow:
●
●
This current multiplied by the R
programming the droop function according to the selected R
Deviations in the current sourced due to errors in the current reading, impacts on the output
voltage depending on the size of R
stage in order to guarantee a maximum deviation of k
Controller tolerance results then to be:
Manuf
Reference tolerance. L6714 is trimmed during the production stage to ensure the
output voltage to be within k
line variations. In addition, the device automatically adds a -19mV offset (Only for Intel
Mode) avoiding the use of any external component. This offset is already included
during the trimming process in order to avoid the use of any external circuit to generate
this offsets and, moreover, avoiding the introduction of any further error to be
considered in the TOB calculation.
Current Reading Circuit. The device reads the current flowing across the MOSFET
RdsON or the inductor DCR by using its dedicated differential inputs. The current
sourced by the VRD is then reproduced and sourced from the DROOP pin scaled down
by a proper designed gain as follow:
can be sliced into different three main categories: Controller Tolerance, External
TOB
TOB
Manuf
Controller
Manuf
P
= V
) that defines the possible output voltage spread across the
=
PP
=
TOB
/2) and temperature measurement error (V
FB
TOB
VID
I
resistor connected from FB pin vs. the load allows
DROOP
FB
2
Controller
VID 19mV
= ±0.5% (±0.6% for AMD DAC) over temperature and
=
resistor. The device is trimmed during the production
TOB
–
=
+
R
---------------------
Manuf
SENSE
TOB
Rg
+
2
CurrSense
k
V
VID
P
IFB
I
+
OUT
2
V
+
= ±1 A from the nominal value.
Tolerance band (TOB) definition
TC
k
+
IDROOP
L
TOB
/Rg gain and R
2
TCMatching
R
FB
TC
2
) must be
FB
resistor.
61/70