NCP5314 ON Semiconductor, NCP5314 Datasheet - Page 23

• Manufacturer Part Number: NCP5314
• Description: Two/Three/Four-Phase Buck CPU Controller
• Manufacturer: ON Semiconductor

below 30 k . As load current increases, the voltage at the
V
causes the voltage at the V
voltage. Figure 29 shows the DC effect of AVP, given an
appropriate resistor ratio.
and R
resistor ratio to achieve the desired loadline. At no load, the
output voltage is positioned 20 mV below the DAC output
setting.
DRP
To choose components, recall that the two resistors R
DRP
pin rises. The ratio of the R
form a voltage divider. Select the appropriate
L1
0 A
L1
I
Lx
I
Lx
0 A
FB
MAX
MAX
pin to rise, reducing the output
/2
/n
R
R
R
R
CS1
CSx
CS1
CSx
C
C
C
V
C
CS1
CSx
CORE
CS1
CSx
DRP
= VID − I
= VID − I
and R
CS1N
CSxN
CS1N
CSxN
Figure 28. AVP Circuitry at Full−Load
Figure 27. AVP Circuitry at No−Load
CS1P
CSxP
CS1P
CSxP
FB
MAX
DRP
+
−
+
−
+
−
+
−
resistors
G
G
G
G
http://onsemi.com
VDRP
VDRP
VDRP
VDRP
w R
w R
FB
L
NCP5314
FB
w G
V
I
VDRP
V
MAX
23
V
DRP
CORE
DRP
I
I
DRP
FBK
The output voltage droop will follow the equation:
where:
w R
= VID +
= VID
R
I
DRP
= VID + IBIAS
COMP
COMP
g = current sense amplifier to V
R
R
L
I
FB
= I
DRP
= I
L
LL
/R
R
R
G
DRP
= ESR of Lo inductor (m );
= 0
MAX
= load line resistance (m ).
DRP
DRP
VDRP
DRP
Error
Error
Amp
Amp
V
V
FB
R
FB
+
−
+
−
L
= VID − 20 mV V
R DRP + g @ R L @ R FB
= VID − 20 mV V
VFB
G
VDRP
VID − 20 mV
w R
VID − 20 mV
I
FB
FB
R
R
+ −
+ −
/R
I
FB
FB
FB
DRP
= 0
R LL
CORE
CORE
DRP
gain (V/V);
(29)