IR3624MTRPBF International Rectifier, IR3624MTRPBF Datasheet - Page 12

• Manufacturer Part Number: IR3624MTRPBF
• Description: IC CTRLR PWM SYNC BUCK 10-MLPD
• Manufacturer: International Rectifier

Specifications of IR3624MTRPBF

• Package / Case: 10-MLPD
• Voltage - Supply: 4.5 V ~ 14 V
• Frequency-max: 660kHz
• Operating Temperature: -40°C ~ 125°C
• Number Of Outputs: 1
• Duty Cycle: 71%
• Pwm Type: Voltage Mode
• Buck: Yes
• Boost: No
• Flyback: No
• Inverting: No
• Doubler: No
• Divider: No
• Cuk: No
• Isolated: No
• Frequency: 600kHz
• Supply Voltage Range: 4.5V To 14V
• Digital Ic Case Style: MLPD
• No. Of Pins: 10
• Operating Temperature Range: -40°C To +125°C
• Termination Type: SMD
• Input Voltage Primary Min: 5V
• Rohs Compliant: Yes
• Filter Terminals: SMD
• Control Mode: Voltage
• Controller Type: PWM
• Package: 10-Lead MLPD
• Circuit: Sync PWM Controller
• Vcc (min): 4.0
• Vcc (max): 14
• Vout (min): 0.6
• Vout (max): Vcc * 0.71
• Iout (a): 10
• Switch Freq (khz): Internal 600kHz
• Pbf: PbF Option Available
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: IR3624MPBFTR

Input Capacitor Selection
The input filter capacitor should be selected
based on how much ripple the supply can
tolerate on the DC input line. The ripple current
generated during the on time of upper MOSFET
should be provided by input capacitor. The RMS
value of this ripple is expressed by:
Where:
D is the Duty Cycle
I
current.
Io is the output current.
For Io=6A and D=0.13, the I
Ceramic capacitors are recommended due to
their peak current capabilities, they also feature
low ESR and ESL at higher frequency which
enhance better efficiency,
Use one 10uF, 25V ceramic capacitor from
Panasonic.
Inductor Selection
The inductor is selected based on output power,
operating frequency and efficiency requirements.
Low inductor value causes large ripple current,
resulting in the smaller size, faster response to a
load transient but poor efficiency and high output
noise. Generally, the selection of inductor value
can be reduced to desired maximum ripple
current in the inductor
usually found between 20% and 50% ripple of
the output current.
For the buck converter, the inductor value for
desired
determined using the following relation:
Where:
V
V
RMS
∆
F
∆
D
in
o
i
t
s
=
=
=
=
=
=
Switching
Duty
Output
Inductor
Turn
Maximum
is the RMS value of the input capacitor
L
V
in
=
I
cycle
RMS
operating
−
on
(
V
V
in
Voltage
o
=
time
−
=
ripple
I
V
frequency
o
L
input
o
∗
∗
)
∗
∆
∆
V
D
t
i
current
in
;
voltage
∗
∗
( i
ripple
( −
V
∆
1
∆
∆
o
t
i
)
=
*
D
F
. The optimum point is
D
s
)
RMS
∗
F
current
1
--(
--(
=2.0A.
s
D =
) 8
) 7
V
V
in
o
can
be
If
L = 0.82uH
The ACT STS703 series provides a range of
inductors in different values, low profile suitable
for large currents.
Output Capacitor Selection
The voltage ripple and transient requirements
determines the output capacitors types and
values. The criteria is normally based on the
value of the Effective Series Resistance (ESR).
However the actual capacitance value and the
Equivalent Series Inductance (ESL)
contributing components, these components can
be described as:
Since the output capacitor has major role in
overall performance of converter and determine
the result of transient response, selection of
capacitor is critical. The IR3624 can perform well
with all types of capacitors.
As a rule the capacitor must have low enough
ESR to meet output ripple and load transient
requirements, yet have high enough ESR to
satisfy stability requirements.
The goal for this design is to meet the voltage
ripple requirement in smallest possible capacitor
size. Therefore ceramic capacitor is selected due
to low ESR and small size. Two of the Panasonic
ECJ2FB0J226M (22uF, 6.3V, X5R and EIA 0805
case size) is a good choice.
In the case of tantalum or low ESR electrolytic
capacitors, the ESR dominates the output
voltage ripple, equation (9) can be used to
calculate the required ESR for the specific
voltage ripple.
∆
∆
∆
∆
∆
∆
V
V
V
V
V
I
∆
L
o
o
o
o
o
i ≈
(
(
(
=
ESR
ESL
C
=
=
)
Inductor
Output
50
=
∆
)
)
=
V
=
8
%(
o
⎛
⎜
⎝
∆
(
*
ESR
V
I
L
C
∆
L
I
in
o
)
I
o
*
)
⎞
⎟
⎠
L
+
, then the output inductor will be:
*
voltage
ESR
*
ripple
F
∆
ESL
s
V
o
(
ESL
)
current
-
ripple
+
-(9)
∆
V
IR3624MPBF
o
(
C
)
are other
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