IR3084AMPBF International Rectifier, IR3084AMPBF Datasheet - Page 27

• Manufacturer Part Number: IR3084AMPBF
• Description: IC XPHASE CONTROL 28-MLPQ
• Manufacturer: International Rectifier
• Series: XPhase™r

Specifications of IR3084AMPBF

• Applications: Processor
• Current - Supply: 14mA
• Voltage - Supply: 9.5 V ~ 16 V
• Operating Temperature: 0°C ~ 100°C
• Mounting Type: Surface Mount
• Package / Case: 28-MLPQ
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Soft Start Capacitor C
Because the capacitor C
delay time, and the frequency of hiccup mode, they should be considered together while choosing C
The soft-start ramp time (TD2) is the time required for the converter’s output voltage to rise from 0V to the DAC
voltage (VDAC). Given a desired soft-start ramp time (TD2) and the soft-start charge current (I
sheet, the value of the external capacitor (C
Once C
and the over-current fault latch delay time
(11), (12), and (13) respectively.
SS/DEL
Where: VDAC = 1.1V in Boot Mode or the DAC voltage set by the VID pins without Boot Mode.
Where: VDAC = 1.1V in Boot Mode or the DAC voltage set by the VID pins without Boot Mode.
If Boot Mode is not used, then TD3 is zero.
Where: TD4 is the VID voltage rise time calculated from Equation 4.
Where: I
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TD
TD
TD
T
C
OCDEL
SS
1
3
5
/
DEL

is determined, the soft start delay time TD1, the VID sample time TD3, the VRRDY delay time TD5,


C
C

RFB is the resistor from Vcore to the FB pin of the controller.
RDRP is the resistor from VDRP to FB.
If droop is not used, set the second term within the parenthesis to zero (RDRP =
ICHG is the soft-start charge current, nominally 70µA.
RFB is the resistor from Vcore to the FB pin of the controller.
RDRP is the resistor from VDRP to FB.
If droop is not used, set the second term within the parenthesis to zero (RDRP =
C
OC_DISCHG

I
SS
I
SS
SS
C
CHG
CHG
VDAC
/
/
/
SS
DEL
DEL
DEL
I
/
OC
DEL
SS/DEL

( *

SS/DEL
_
is the over-current discharge current of the SS/DEL pin from the data sheet.




I
DISCHG

*
. 3
1
3
CHG
100



I
3 .
1 .
85
1
CHG
V
V
and Resistor R

V
mV
programs three different time parameters, i.e. soft start time, over current latch


RFB
*

1
VDAC
TD
3 .
3

1 .
V
RFB

2
V
C

RDRP
)
SS
1


1 .
SS/DEL
/
40
T
RFB
DEL
TD
V
OCDEL
SS/DEL
*




*
4

10
) can be calculated using Equation (9).
RFB
100



70

are determined and can be calculated using Equations (10),
C
VDAC
RDRP
6
C
SS
mV
*
SS
/
10
DEL
70
/
DEL

70
6
*




10




*
*
1
0
. 0
10


7 .
6
75
V
RFB

6
V
*
TD

RFB

TD
RDRP
2
4



IR3084A
CHG
3/3/2009
∞
∞
(9)
(10)
(11)
(12)
(13)
) from the data
).
).
SS/DEL
.