IR3080 International Rectifier, IR3080 Datasheet - Page 22

• Manufacturer Part Number: IR3080
• Description: XPHASE VRD10 CONTROL IC WITH VCCVID & OVERTEMP DETECT
• Manufacturer: International Rectifier

No Load Output Voltage Setting Resistor R
A resistor between FB pin and the converter output is used to create output voltage offset V
difference between V
lowers the converter voltage by R
R
adaptive voltage positioning resistor R
are determined by (16) and (17) respectively,
Control IC Over Temperature Setting Resistors R
The threshold voltage of VRHOT comparator is proportional to the die temperature T
shown in Equation (18). Determine the relationship between the die temperature of IR3080 and the temperature of
the power converter according to the power loss, PCB layout and airflow, etc. Then calculate the VRHOT threshold
voltage corresponding to the temperature.
Use VBIAS as the reference voltage. If R
Equation (19).
Body Braking
The body braking
enabled, Resistors R
Dynamic VID step down. Usually R
IR3086 EXTERNAL COMPONENTS
PWM Ramp Resistor R
PWM ramp is generated by connecting the resistor R
as the capacitor C
and the capacitor C
Equation (20). To achieve feed-forward voltage mode control, the resistor R
of the converter.
Inductor Current Sensing Capacitor C
The DC resistance of the inductor is utilized to sense the inductor current. Usually the resistor R
C
across the capacitor C
component of the capacitor voltage is different from that of the real inductor current. The time constant mismatch
does not affect the average current sharing among the multiple phases, but affect the current signal ISHARE as well
as the output voltage during the load current transient if adaptive voltage positioning is adopted.
FB
CS+
Page 22 of 41
is not only determined by I
in parallel with the inductor are chosen to match the time constant of the inductor, and therefore the voltage
TM
Related Resistors R
TM
PWMRMP
V
R
R
R
R
VRHOT
PWMRMP
HOTSETC
PWMRMP
FB
DRP
during Dynamic VID can be disabled by connecting BBFB pin to ground. If the feature is
BBFB
DAC
CS+
=
PWMRMP
=
R
represents the inductor current. If the two time constants are not the same, the AC
=
voltage and output voltage at no load condition. Adaptive voltage positioning further
R
L
and R
between PWMRMP and LGND. Choose the desired PWM ramp magnitude V
2
. 4
FB
_
=
=
MAX
in the range of 100pF and 470pF, and then calculate the resistor R
73
V
FB
∗
R
IN
*
R
HOTSETC
and Capacitor C
O
, the current flowing out of FB pin as shown in Figure 14, but also affected by the
10
∗
*
BBDRP
L
*I
BBFB
V
_
n
f
−
O,
O
MAX
SW
3
∗
*
_
DRP
BBFB
where R
R
I
NLOFST
T
*
1
FB
and R
CS+
O
J
C
∗
V
are needed to restore the feedback voltage of the error amplifier after
+
VBIAS
G
PWMRMP
∗
and total input offset voltage of current sense amplifiers. R
. 1
HOTSETC1
CS
and R
R
and Resistors R
V
241
FB
−
L
VRHOT
_
BBDRP
+
O
_
MIN
V
MAX
V
and Adaptive Voltage Positioning Resistor R
CS
is the required output impedance of the converter.
*
VRHOT
BBDRP
PWMRMP
[ln(
_
TOFST
HOTSETC1
are chosen to match R
PWMRMP
V
is pre selected, R
IN
−
∗
V
V
n
O
DAC
∗
CS+
R
and R
between a voltage source and PWMRMP pin as well
O
)
−
and R
ln(
V
HOTSETC2
IN
CS-
−
HOTSETC2
V
DAC
FB
RAMP
and R
−
V
PWMRMP
should be connected to the input
can be calculated according to
DRP
J
(ºC) of control IC IR3080, as
)]
respectively
(16)
(17)
(18)
(19)
(20)
O_NLOFST,
DRP
CS+
9
/30/04
IR3080
.
PWMRMP
and capacitor
FB
which is the
and R
PWMRMP
from
DRP