IR3831WMTR1PBF International Rectifier, IR3831WMTR1PBF Datasheet - Page 22

• Manufacturer Part Number: IR3831WMTR1PBF
• Description: IC REG SYNC BUCK 8A 15-QFN
• Manufacturer: International Rectifier
• Series: SupIRBuck™r

Specifications of IR3831WMTR1PBF

• Applications: Converter, DDR
• Voltage - Input: 1.5 ~ 16 V
• Number Of Outputs: 1
• Voltage - Output: 0.6 ~ 14.4 V
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: 15-PowerVQFN
• Part Status: Preferred
• Package: PQFN / 5 x 6
• Circuit: Single Output
• Iout (a): 8
• Switch Freq (khz): 250 - 1500
• Input Range (v): 1.5 - 16
• Output Range (v): 0.7 - 0.9*Vin
• Ocp Otp Uvlo Pre-bias Soft Start And: PGOOD + EN + OVD + DDR Tracking
• Server Storage: Yes
• Routers Switches: Yes
• Base Station Telecom: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: IR3831WMTR1PBFTR

Detailed calculation of compensation TypeIII
Rev 14.0
C
C
Desired
F
F
Select
F
Select
Calculate
R
Select
Calculate
R
R
Select
Z
P
P
4
3
10
8
3
2
3
2
=
=
=
=
=
=
=
=
2
2
2
2
F
F
0.5
2
π
π
:
π
π
:
:
:
π
o
o
C
R
F
R
*
*
*
*
7
*
Z
8
*
3
F
C
F
F
Phase
1
1
1
1
1
C
1
F
1
P
=
o
Z
1
=
R
=
R
−
+
+
−
7
1
=
s
1
3
7
C
*
10
2.2
3
6.65
sin
1.47
*
sin
sin
sin
*
*
*
0
=
,
L
7
F
,
R
.
R
F
C
o
5
Z
200
*
R
nF
P
3
2
Θ
Θ
3
V
3
Θ
Θ
*
*
2
8
k
;
k
C
in
;
F
-
Margin
and
C
;
C
Ω
Ω
=
R
=
Z
and
o
3
2
4
kHz
R
10
10.58
340.28
*
=
=
=
10
V
;
C
osc
541.34
20.47
R
5.29
R
=
4
8
9
215
:
;
Θ
=
R
:
kHz
kHz
6.63
3
=
kHz
nF,
70
=
Ω
pF
1.48
,
,
o
k
Select
Select
and
Ω
Select
,
k
Ω
:
:
:
R
C
C
10
4
3
=
=
=
22
560
210
nF
pF
Ω
Programming the Current-Limit
The Current-Limit threshold can be set by
connecting a resistor (R
to the OCSet pin. The resistor can be calculated
by using equation (4). This resistor R
be placed close to the IC.
The
coefficient and it should be considered for the
worst case operation.
Setting the Power Good Threshold
A window comparator internally sets a lower
Power Good threshold at 85% of Vp and an
upper Power Good threshold at 115% of Vp.
When the voltage at the FB pin is within the
window set by these thresholds, PGood is
asserted.
The PGood is an open drain output. Hence, it is
necessary to use a pull up resistor R
PGood pin to Vcc.
resistor must be chosen such as to limit the
current flowing into the PGood pin, when the
output voltage is not in regulation, to less than 5
mA. A typical value used is 4.7kΩ.
I
SET
R
I
(50%
I
R
SET
OCSet
OCSet
=
DS
R
I
(
DS(on)
≅
L
on
(
=
critical
)
I
=
( o
over
=
39.22
LIM
3.25
8.5
)
)
=
=
has
m
k
8
nominal
μA
R
Ω
Ω
IR3831WMPbF
OCSet
A
*
*
R
1.25
Select
(at
1.5
DS
a
The value of the pull-up
∗
(
on
F
OCSET
=
I
=
OCSet
s
positive
)
12
10.625
output
=
400
R
A
) from the SW pin
7
..........
=
kHz)
3.24
m
current)
Ω
temperature
..........
OCSET
k
Ω
PG
...
must
(32)
22
from