L6918A STMicroelectronics, L6918A Datasheet - Page 17

• Manufacturer Part Number: L6918A
• Description: 5 BIT PROGRAMMABLE MULTIPHASE CONTROLLER
• Manufacturer: STMicroelectronics

FB and COMP has always a capacitor in series (See fig. 8). The voltage regulated by each device is then equal
to:
Where I
devices N)
Since I
load current is given by:
Where R
each device (that is the total current delivered to the load I
Figure 7. Output transient response without (a) and with (b) the droop function
Figure 8. Active Droop Function Circuit
The feedback current is equal to 50 A at nominal full load (I
tion threshold, so the maximum output voltage deviation is equal to:
FB
OUT
OUT
depends on the current information about the two phases of each device, the output characteristic vs.
is the output current of each device (equal to the total load current I
is the equivalent output resistance due to the droop function and I
V
OUT
V
FULL _POSITIVE_LOAD
V
N O M
=
VID R
–
V
E S R D R O P
FB
OUT
I
COMP
COMP
(a)
O UT
=
=
VID R
+R
=
VID R
F B
–
–
FB
50 A
F B
Ref
Ref
I
F B
Total Current Info (I
Total Current Info (I
R
--------------------- - I
=
FB
FB
V
SENSE
V
M A X
M IN
Rg
VID R
LOAD
FB
–
R
R
V
V
= I
DROOP
DROOP
FB
FB
OUT
V
F B
divided by 2.
O L_INTERVENTION
INFO1
R
--------------------- - I
=
E S R D R O P
SENSE
VID R
Rg
+ I
INFO1
INFO1
(b)
INFO2
–
+I
+I
F B
INFO2
INFO2
OUT
) and 70 A at the OCP interven-
OUT
To V
To V
LOAD
R
--------------------- -
)
)
=
S ENSE
Rg
+R
is still the output current of
OUT
OUT
divided by the number of
F B
I
---------------
V
70 A
L OAD
D R O O P
2
L6918 L6918A
17/35