L6714 STMicroelectronics, L6714 Datasheet - Page 57

• 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
21
System control loop compensation
The control loop is composed by the Current Sharing control loop
Average Current Mode control loop. Each loop gives, with a proper gain, the correction to
the PWM in order to minimize the error in its regulation: the Current Sharing control loop
equalize the currents in the inductors while the Average Current Mode control loop fixes the
output voltage equal to the reference programmed by VID.
diagram of the system control loop.
The system Control Loop is reported in
by the DROOP pin flows into R
the read current.
Figure 22. Main control loop
The system can be modeled with an equivalent single phase converter which only difference
is the equivalent inductor L/N (where each phase has an L inductor).The Control Loop gain
results (obtained opening the loop after the COMP pin):
CURRENT SHARING
CORRECTION
DUTY CYCLE
1 / 5
1 / 5
1 / 5
1 / 5
G
LOOP
s
=
–
FB
I
I
I
I
INFO1
INFO2
INFO3
INFO4
------------------------------------------------------------------------------------------------------------------------ -
Z
implementing the dependence of the output voltage from
P
s
PWM
+
Figure
Z
PWM3
PWM2
PWM1
PWM4
L
4 / 5
s
Z
ERROR AMPLIFIER
F
23. The current information I
COMP
s
Z
--------------
A s
F
R
s
System control loop compensation
DROOP
+
1
L4
L3
L2
L1
Z
Figure 22
+
F
(s)
+
----------- -
A s
1
Z
P
s
FB
(See Figure
V
REF
R
shows the block
FB
DROOP
DROOP
I
DROOP
C
OUT
8) and the
Z
FB
sourced
(s)
R
OUT
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