MP2403
3A, 32V, 250kHz Integrated Synchronous
Step-Down Converter
The Future of Analog IC Technology
DESCRIPTION
FEATURES
The MP2403 is a monolithic synchronous buck
regulator. The device integrates a 150mΩ
high-side MOSFET and an 80mΩ low-side
MOSFET that provides 3A continuous load
current over a wide operating input voltage of
4.6V to 32V. Current mode control provides fast
transient response and cycle-by-cycle current
limit.
An adjustable soft-start prevents inrush current
at turn-on. In shutdown mode, the supply
current drops to 1μA.
This device, available in an 8-pin SOIC
package, provides a very compact system
solution with minimal reliance on external
components.
EVALUATION BOARD REFERENCE
Board Number
Dimensions
EV2403DN-00A
2.0”X x 1.5”Y x 0.5”Z
3A Output Current
Wide 4.6V to 32V Operating Input Range
Integrated MOSFET Switches
Output Adjustable from 0.80V to 28V
Up to 95% Efficiency
Programmable Soft-Start
Stable with Low ESR Ceramic Output Capacitors
Fixed 250kHz Frequency
Cycle-by-Cycle Over Current Protection
Input Under Voltage Lockout
Thermally Enhanced 8-Pin SOIC Package
APPLICATIONS
Distributed Power Systems
Pre-Regulator for Linear Regulators
Notebook Computers
“MPS” and “The Future of Analog IC Technology” are Registered Trademarks of
Monolithic Power Systems, Inc.
TYPICAL APPLICATION
Efficiency vs
Output Current
100
INPUT
4.6V to 32V
VIN=12V
90
OFF
2
IN
7
EN
8
1
BS
3
SW
MP2403
SS
GND
4
FB
COMP
6
5
OUTPUT
3.3V
3A
EFFICIENCY(%)
80
ON
VIN=5V
70
VIN=24V
60
50
VIN=32V
40
30
20
10
0
VOUT=3.3V
0
1
2
3
OUTPUT CURRENT(A)
MP2403 Rev.1.0
1/21/2020
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MP2403 – 3A, 32V, 250kHz INTEGRATED SYNCHRONOUS STEP-DOWN CONVERTER
ORDERING INFORMATION
Part Number*
Package
Top Marking
Free Air Temperature (TA)
MP2403DN
SOIC8N
(Exposed Pad)
MP2403DN
-40C to +85C
* For Tape & Reel, add suffix –Z (e.g. MP2403DN–Z).
For Lead Free, add suffix –LF (e.g. MP2403DN–LF–Z)
PACKAGE REFERENCE
TOP VIEW
BS
1
8
SS
IN
2
7
EN
SW
3
6
COMP
GND
4
5
FB
CONNECT EXPOSED PAD
AND GND PIN TO A CERTAIN
GROUND PLANE
ABSOLUTE MAXIMUM RATINGS (1)
Thermal Resistance (4)
Supply Voltage VIN ........................ -0.3V to +35V
Switch Voltage VSW .................. -1V to VIN + 0.3V
Boost Voltage VBS ...........VSW - 0.3V to VSW + 6V
All Other Pins ................................. –0.3V to +6V
Continuous Power Dissipation (TA = +25°C) (2)
………………………………………………....2.5W
Junction Temperature ............................... 150°C
Lead Temperature .................................... 260°C
Storage Temperature ...............-65°C to +150°C
SOIC8N ................................... 50 ...... 10... C/W
Recommended Operating Conditions (3)
Input Voltage VIN .............................. 4.6V to 32V
Output Voltage VOUT ....................... 0.80V to 28V
Operating Junct. Temp (TJ) ....... -40°C to +125°C
MP2403 Rev.1.0
1/21/2020
θJA
θJC
Notes:
1) Exceeding these ratings may damage the device.
2) The maximum allowable power dissipation is a function of the
maximum junction temperature TJ (MAX), the junction-toambient thermal resistance θJA, and the ambient temperature
TA. The maximum allowable continuous power dissipation at
any ambient temperature is calculated by PD (MAX) = (TJ
(MAX)-TA)/θJA. Exceeding the maximum allowable power
dissipation will cause excessive die temperature, and the
regulator will go into thermal shutdown. Internal thermal
shutdown circuitry protects the device from permanent
damage.
3) The device is not guaranteed to function outside of its
operating conditions.
4) Measured on JESD51-7, 4-layer PCB.
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MP2403 – 3A, 32V, 250kHz INTEGRATED SYNCHRONOUS STEP-DOWN CONVERTER
ELECTRICAL CHARACTERISTICS (5)
VIN = 12V, TA = +25°C, unless otherwise noted.
Parameter
Shutdown Supply Current
Supply Current
Feedback Voltage
OVP Threshold Voltage
Error Amplifier Voltage Gain
Error Amplifier Transconductance
High-Side Switch-On Resistance
Low-Side Switch-On Resistance
High-Side Switch Leakage Current
Upper Switch Current Limit
Lower Switch Current Limit
COMP to Current Sense
Transconductance
Symbol Condition
VEN = 0V
VEN = 2.7V, VFB = 1.0V
4.6V VIN 32V,
T
A = +25°C
VFB
-40°C ≤ TA ≤ +85°C
AEA
GEA
Typ (4)
0.3
1.45
Max
3.0
1.6
Units
μA
mA
0.780
0.800
0.820
V
0.835
1.00
V
V
V/V
μA/V
mΩ
mΩ
μA
A
A
0.765
0.90
550
RDS(ON)1
RDS(ON)2
VEN = 0V, VSW = 0V
4.3
From Drain to Source
GCS
Oscillation Frequency
Fosc1
Short Circuit Oscillation Frequency
Maximum Duty Cycle
Minimum On Time
EN Shutdown Threshold Voltage
EN Threshold Voltage Hysteresis
Input Under Voltage Lockout
Threshold
Fosc2
DMAX
Input Under Voltage Lockout
Threshold Hysterisis
Soft-Start Current
Thermal Shutdown
IC = 10μA
Min
UVLO
0.95
400
820
150
80
0
5.3
1.25
1100
10
7
TA = +25°C
-40°C ≤ TA ≤ +85°C
VFB = 0V
VFB = 0.7V
215
195
VEN Rising
1.0
VIN rising, TA = +25°C
3.6
0°C ≤ TA ≤ +70°C
3.2
VSS = 0V
85
250
55
90
180
1.3
205
3.95
A/V
285
305
1.6
kHz
kHz
kHz
%
ns
V
mV
4.3
V
4.5
V
125
mV
6
160
μA
°C
Notes:
5) 100% production test at +25°C. Specifications over the temperature range are guaranteed by design and characterization.
MP2403 Rev.1.0
1/21/2020
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MP2403 – 3A, 32V, 250kHz INTEGRATED SYNCHRONOUS STEP-DOWN CONVERTER
PIN FUNCTIONS
Pin #
Name
1
BS
2
IN
3
SW
4
5
6
7
8
Description
High-Side Gate Drive Boost Input. BS supplies the drive for the high-side N-Channel
MOSFET switch. Connect a 0.01μF or greater capacitor from SW to BS to power the
high side switch.
Power Input. IN supplies the power to the IC, as well as the step-down converter
switches. Drive IN with a 4.6V to 32V power source. Bypass IN to GND with a suitably
large capacitor to eliminate noise on the input to the IC. See Input Capacitor.
Power Switching Output. SW is the switching node that supplies power to the output.
Connect the output LC filter from SW to the output load. Note that a capacitor is
required from SW to BS to power the high-side switch.
GND,
Ground. The Exposed Pad and GND pin must be connected to the same ground plane.
Exposed Pad
Feedback Input. FB senses the output voltage to regulate that voltage. Drive FB with a
FB
resistive voltage divider from the output voltage. The feedback threshold is 0.80V. See
Setting the Output Voltage.
Compensation Node. COMP is used to compensate the regulation control loop.
Connect a series RC network from COMP to GND to compensate the regulation control
COMP
loop. In some cases, an additional capacitor from COMP to GND is required. See
Compensation Components.
Enable Input. EN is a digital input that turns the regulator on or off. Drive EN high to
EN
turn on the regulator, drive it low to turn it off. Pull up with 100kΩ resistor to IN for
automatic startup.
Soft-start Control Input. SS controls the soft-start period. Connect a capacitor from SS
SS
to GND to set the soft-start period. A 0.1μF capacitor sets the soft-start period to 15ms.
To disable the soft-start feature, leave SS unconnected.
MP2403 Rev.1.0
1/21/2020
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MP2403 – 3A, 32V, 250kHz INTEGRATED SYNCHRONOUS STEP-DOWN CONVERTER
TYPICAL PERFORMANCE CURVES
VIN = 12V, VOUT = 3.3V, TA = +25C, unless otherwise noted.
Load Regulation
Line Regulation
VOUT = 3.3V
0.5%
VIN=12V
VIN=5V
VIN=24V
VIN=30V
-0.5%
-1.0%
1
2
3
OUTPUT CURRENT(A)
0
4
1.0%
7
6
0.5%
IOUT=0A
0.0%
IOUT=1.5A
PEAK CURRENT (A)
OUTPUT VOLTAGE (VARIATION)
OUTPUT VOLTAGE (VARIATION)
VOUT = 3.3V
1.0%
0.0%
Peak Current vs
Duty Cycle
IOUT=3A
-0.5%
5
4
3
2
1
-1.0%
0
Operating Range
10
20
30
INPUT VOLTAGE(V)
0
40
0
0.2
0.4
DUTY
0.6
Output Ripple Voltage
Output Ripple Voltage
IO = 0A
IO = 3A
0.8
OUTPUT VOLTAGE (V)
100
DMAX
VIN_MAX
10
VIN_MIN
VO
10mV/div.
VO
10mV/div.
Iinductor
1A/div.
Iinductor
1A/div.
SW
5V/div.
SW
5V/div.
TON_MIN
1
0.1
0
10
20
30
INPUT VOLTAGE (V)
40
2us/div.
2us/div.
Input Ripple Voltage
Input Ripple Voltage
Loop Response
IO = 0A
IO = 3A
IO = 1.5A-3A
VIN
200mV/div.
VIN
10mV/div.
VO
100mV/div.
Iinductor
1A/div.
Iinductor
1A/div.
SW
5V/div.
SW
5V/div.
2us/div.
MP2403 Rev.1.0
1/21/2020
Iinductor
1A/div.
2us/div.
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100us/div.
5
MP2403 – 3A, 32V, 250kHz INTEGRATED SYNCHRONOUS STEP-DOWN CONVERTER
TYPICAL PERFORMANCE CURVES (continued)
VIN = 12V, VOUT = 3.3V, TA = +25C, unless otherwise noted
Short Circuit Recovery
Short Circuit Entry
Frequency Fold Back
With output short
VO
2V/div.
VO
2V/div.
Iinductor
2A/div.
SW
10V/div.
SW
10V/div.
Iinductor
2A/div.
10us/div.
VO
2V/div.
SW
10V/div.
Iinductor
5A/div.
40us/div.
100us/div.
Enable Startup at No Load
Enable Shutdown at No Load
Enable Startup at Full Load
RLOAD
VO
2V/div.
VO
2V/div.
VO
2V/div.
EN
5V/div.
Iinductor
2A/div.
EN
5V/div.
Iinductor
2A/div.
EN
5V/div.
Iinductor
2A/div.
SW
10V/div.
SW
10V/div.
SW
10A/div.
1s/div.
2ms/div.
Enable Shutdown at Full Load
2ms/div.
Power Up at No Load
Power Up at Full Load
RLOAD = 1.1
VO
2V/div.
VO
2V/div.
VO
2V/div.
EN
5V/div.
Iinductor
2A/div.
SW
10A/div.
40us/div.
MP2403 Rev.1.0
1/21/2020
VIN
5V/div.
VIN
5V/div.
SW
10V/div.
Iincdutor
2A/div.
Iinductor
2A/div.
SW
10A/div.
2ms/div.
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2ms/div.
6
MP2403 – 3A, 32V, 250kHz INTEGRATED SYNCHRONOUS STEP-DOWN CONVERTER
BLOCK DIAGRAM
+
CURRENT
SENSE
AMPLIFIER
OVP
0.95V
-OSCILLATOR
+
FB
250kHz
0.3V
RAMP
5V
BS
-+
--
+
0.8V
+
--
CLK
-SS
IN
+
ERROR
AMPLIFIER
S
Q
R
Q
SW
CURRENT
COMPARATOR
COMP
GND
EN
OVP
1.2V
IN < 3.95V
IN
--
1.3 V
+
INTERNAL
REGULATORS
SHUTDOWN
COMPARATOR
Figure 1—Functional Block Diagram
OPERATION
FUNCTIONAL DESCRIPTION
The MP2403 is a fully-integrated synchronous
current-mode step-down regulator. It regulates
input voltages from 4.6V to 32V down to an
output voltage as low as 0.80V, and supplies up
to 3A of load current.
The MP2403 uses current-mode control to
regulate the output voltage. The output voltage
is measured at FB through a resistive voltage
divider and amplified through the internal
transconductance error amplifier. The voltage at
COMP pin is compared to the switch current
measured internally to control the output
voltage.
MP2403 Rev.1.0
1/21/2020
The converter uses internal N-Channel
MOSFET switches to step-down the input
voltage to the regulated output voltage. Since
the high side MOSFET requires a gate voltage
greater than the input voltage, a boost capacitor
connected between SW and BS is needed to
drive the high-side gate. The boost capacitor is
charged from the internal 5V rail when SW is low.
When the MP2403 FB pin exceeds 20% of the
nominal regulation voltage of 0.80V, the over
voltage comparator is tripped and latched; the
COMP pin and the SS pin are discharged to
GND, forcing the high-side switch off.
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MP2403 – 3A, 32V, 250kHz INTEGRATED SYNCHRONOUS STEP-DOWN CONVERTER
APPLICATIONS INFORMATION
COMPONENT SELECTION
Setting the Output Voltage
The output voltage is set using a resistive voltage
divider from the output voltage to FB pin. The
voltage divider divides the output voltage down to
the feedback voltage by the ratio:
VFB VOUT
R2
R1 R2
Thus the output voltage is:
VOUT 0.80
R1 R2
R2
Where VFB is the feedback voltage and VOUT is the
output voltage.
R2 can be as high as 100kΩ, but a typical value is
10kΩ. Using that value, R1 is determined by:
R1 12.5 ( VOUT 0.80)(k)
For example, for a 3.3V output voltage, R2 is
10kΩ, and R1 is 31.25kΩ.
Inductor
The inductor is required to supply constant current
to the output load while being driven by the
switched input voltage. A larger value inductor will
result in less ripple current that will result in lower
output ripple voltage. However, the larger value
inductor will have a larger physical size, higher
series resistance, and/or lower saturation current.
A good rule for determining the inductance value
is to allow the peak-to-peak ripple current in the
inductor to be approximately 30% of the maximum
switching current limit. Also, make sure that the
peak inductor current is below the maximum
switch current limit. The inductance value can be
calculated by:
L
VOUT
V
1 OUT
fS ∆I
VIN
Where VIN is the input voltage, fS is the 250KHz
switching frequency, and ∆IL is the peak-to-peak
inductor ripple current.
Choose an inductor that will not saturate under
the maximum inductor peak current. The peak
inductor current can be calculated by:
ILP ILOAD
V
VOUT
1 OUT
VIN
2 fS L
Where ILOAD is the load current.
Optional Schottky Diode
During the transition between high-side switch
and low-side switch, the body diode of the lowside power MOSFET conducts the inductor
current. The forward voltage of this body diode is
high. An optional Schottky diode may be
paralleled between the SW pin and GND pin to
improve overall efficiency. Table 2 lists example
Schottky diodes and their Manufacturers.
Table 2—Diode Selection Guide
B340
SK34
Voltage/Current
Rating
40V, 3A
40V, 3A
MBRS340
40V, 3A
Part Number
Vendor
Diodes, Inc.
Diodes, Inc.
International
Rectifier
Input Capacitor
The input current to the step-down converter is
discontinuous, therefore a capacitor is required to
supply the AC current to the step-down converter
while maintaining the DC input voltage. Use low
ESR capacitors for the best performance.
Ceramic capacitors are preferred, but low-ESR
electrolytic capacitors may also suffice. Choose
X5R or X7R dielectrics when using ceramic
capacitors.
Since the input capacitor (C1) absorbs the input
switching current it requires an adequate ripple
current rating. The RMS current in the input
capacitor can be estimated by:
IC1 ILOAD
VOUT
V
(1 OUT )
VIN
VIN
The worst-case condition occurs at VIN = 2VOUT,
where:
I C1
ILOAD
2
For simplification, choose an input capacitor with
an RMS current rating greater than half of the
maximum load current.
MP2403 Rev.1.0
1/21/2020
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MP2403 – 3A, 32V, 250kHz INTEGRATED SYNCHRONOUS STEP-DOWN CONVERTER
The input capacitor can be electrolytic, tantalum
or ceramic. When using electrolytic or tantalum
capacitors, a small, high quality ceramic capacitor
(i.e. 0.1μF), should be placed as close to the IC
as possible. When using ceramic capacitors,
make sure that they have enough capacitance to
provide sufficient charge to prevent excessive
voltage ripple at input. The input voltage ripple
caused by capacitance can be estimated by:
VIN
ILOAD
V
V
OUT 1 OUT
f S C1 VIN
VIN
Output Capacitor
The output capacitor is required to maintain the
DC output voltage. Ceramic, tantalum, or low
ESR electrolytic capacitors are recommended.
Low ESR capacitors are preferred to keep the
output voltage ripple low. The output voltage
ripple can be estimated by:
VOUT
VOUT
V
1 OUT
f S L
VIN
1
R ESR
8
f
C
2
S
Where C2 is the output capacitance value and
RESR is the equivalent series resistance (ESR)
value of the output capacitor.
In the case of ceramic capacitors, the impedance
at the switching frequency is dominated by the
capacitance. The output voltage ripple is mainly
caused by the capacitance. For simplification, the
output voltage ripple can be estimated by:
∆VOUT
V
1 OUT
VIN
L C2
VOUT
8 fS
2
In the case of tantalum or electrolytic capacitors,
the ESR dominates the impedance at the
switching frequency. For simplification, the output
ripple can be approximated to:
∆VOUT
VOUT
V
1 OUT
f S L
VIN
R ESR
The characteristics of the output capacitor also
affect the stability of the regulation system. The
MP2403 can be optimized for a wide range of
capacitance and ESR values.
MP2403 Rev.1.0
1/21/2020
Compensation Components
MP2403 employs current mode control for easy
compensation and fast transient response. The
system stability and transient response are
controlled through the COMP pin. COMP pin is
the output of the internal transconductance
error amplifier. A series capacitor-resistor
combination sets a pole-zero combination to
control the characteristics of the control system.
The DC gain of the voltage feedback loop is
given by:
A VDC R LOAD G CS A VEA
VFB
VOUT
Where AVEA is the error amplifier voltage gain,
400V/V;
GCS
is
the
current
sense
transconductance, 7.0A/V; RLOAD is the load
resistor value.
The system has 2 poles of importance. One is
due to the compensation capacitor (C3) and the
output resistor of error amplifier, and the other
is due to the output capacitor and the load
resistor. These poles are located at:
fP1
GEA
2 C3 A VEA
fP 2
1
2 C2 R LOAD
Where GEA is the error amplifier transconductance,
820μA/V, and RLOAD is the load resistor value.
The system has one zero of importance, due to the
compensation
capacitor
(C3)
and
the
compensation resistor (R3). This zero is located at:
f Z1
1
2 C3 R3
The system may have another zero of
importance, if the output capacitor has a large
capacitance and/or a high ESR value. The zero,
due to the ESR and capacitance of the output
capacitor, is located at:
fESR
1
2 C2 R ESR
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MP2403 – 3A, 32V, 250kHz INTEGRATED SYNCHRONOUS STEP-DOWN CONVERTER
In this case, a third pole set by
compensation capacitor (C6) and
compensation resistor (R3) is used
compensate the effect of the ESR zero on
loop gain. This pole is located at:
fP 3
the
the
to
the
1
2 C6 R3
The goal of compensation design is to shape
the converter transfer function to get a desired
loop gain. The system crossover frequency
where the feedback loop has the unity gain is
important.
Lower crossover frequencies result in slower
line and load transient responses, while higher
crossover frequencies could cause system
unstable. A good rule of thumb is to set the
crossover frequency to approximately one-tenth
of the switching frequency. Switching frequency
for the MP2403 is 250KHz, so the desired
crossover frequency is 25KHz.
Table 3 lists the typical values of compensation
components for some standard output voltages
with various output capacitors and inductors. The
values of the compensation components have
been optimized for fast transient responses and
good stability at given conditions.
To optimize the compensation components for
conditions not listed in Table 2, the following
procedure can be used.
1. Choose the compensation resistor (R3) to set
the desired crossover frequency. Determine the
R3 value by the following equation:
R3
2 C2 f C VOUT
G EA G CS
VFB
Where fC is the desired crossover frequency,
25KHz.
2. Choose the compensation capacitor (C3) to
achieve the desired phase margin. For
applications with typical inductor values, setting
the compensation zero, fZ1, below one forth of
the crossover frequency provides sufficient
phase margin. Determine the C3 value by the
following equation:
C3
MP2403 Rev.1.0
1/21/2020
Table 3—Compensation Values for Typical
Output Voltage/Capacitor Combinations
VOUT
1.8V
L
4.7μH
C2
R3
C3
C6
100μF
Ceramic
5.6kΩ
3.3nF
None
2.5V
4.76.8μH
47μF
Ceramic
4.7kΩ
4.7nF
None
3.3V
6.810μH
22μFx2
Ceramic
5.6kΩ
3.3nF
None
5V
1015μH
22μFx2
Ceramic
7.5kΩ
3.3nF
None
12V
1522μH
22μFx2
Ceramic
10kΩ
1.2nF
None
1.8
4.7μH
100μF
SP-CAP
10kΩ
2.2nF 100pF
2.5V
4.76.8μH
47μF
SP-CAP
5.6kΩ
3.3nF
None
3.3V
6.810μH
47μF
SP-CAP
6.8kΩ
2.2nF
None
5V
1015μH
47μF
SP CAP
10kΩ
2.2nF
None
2.5V
4.76.8μH
560μF Al.
30mΩ ESR
10kΩ
7.5nF
1.5nF
3.3V
6.810μH
560μF Al
30mΩ ESR
10kΩ
10nF
1.5nF
5V
1015μH
470μF Al.
30mΩ ESR
15kΩ
7.5nF
1nF
12V
1522μH
220μF Al.
30mΩ ESR
15kΩ
10nF
390pF
3. Determine if the second compensation
capacitor (C6) is required. It is required if the
ESR zero of the output capacitor is located at
less than half of the 250KHz switching
frequency, or the following relationship is valid:
f
1
S
2 C2 R ESR
2
If this is the case, then add the second
compensation capacitor (C6) to set the pole fP3
at the location of the ESR zero. Determine the
C6 value by the equation:
C6
C2 R ESR
R3
4
2 R3 f C
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MP2403 – 3A, 32V, 250kHz INTEGRATED SYNCHRONOUS STEP-DOWN CONVERTER
External Bootstrap Diode
An external bootstrap diode may enhance the
efficiency of the regulator, the applicable
conditions of external BST diode are:
VOUT is 5V or 3.3V; and
Duty cycle is high: D=
External BST Diode
IN4148
BST
MP2403
SW
VOUT
>65%
VIN
CBST
L
5V or 3.3V
COUT
Figure 2—Add Optional External Bootstrap
Diode to Enhance Efficiency
In these cases, an external BST diode is
recommended from the output of the voltage
regulator to BST pin, as shown in Fig.2
The recommended external BST diode is IN4148,
and the BST cap is 0.1~1µF.
TYPICAL APPLICATION CIRCUITS
C5
10nF
INPUT
4.6V to 32V
7
1
BS
3
SW
2
IN
EN
OUTPUT
2.5V
3A
MP2403
8
SS
GND
FB
COMP
4
5
6
C6
C3
4.7nF
D1
B340
(optional)
(optional)
Figure 3—MP2403 with AVX 47μF, 6.3V Ceramic Output Capacitor
MP2403 Rev.1.0
1/21/2020
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MP2403 – 3A, 32V, 250kHz INTEGRATED SYNCHRONOUS STEP-DOWN CONVERTER
PCB Layout Guide
2)
PCB layout is very important to achieve stable
operation. It is highly recommended to duplicate
EVB layout for optimum performance.
Bypass ceramic capacitors are suggested
to be put close to the Vin Pin.
3)
Ensure all feedback connections are short
and direct. Place the feedback resistors
and compensation components as close to
the chip as possible.
4)
Rout SW away from sensitive analog areas
such as FB.
5)
Connect IN, SW, and especially GND
respectively to a large copper area to cool
the chip to improve thermal performance
and long-term reliability.
If change is necessary, please follow these
guidelines and take Figure 4 for reference.
1) Keep the path of switching current short and
minimize the loop area formed by Input cap,
high-side MOSFET and low-side MOSFET.
C5
INPUT
4.75V to 23V
R4
2
7
8
C1
1
IN
BS
SW
EN
MP2403
SS
GND
4
FB
COMP
OUTPUT
R1
5
6
C3
C4
L1
3
D1
(optional)
R2
C2
R3
MP2403 Typical Application Circuit
FB 5
EN 7
C3
COMP 6
C4
SS 8
R4
R3
PGND
R1
R2
SGND
R1
C5
4 GND
3 SW
2 IN
1 BS
PGND
D1
C2
C1
L1
Top Layer
Bottom Layer
Figure 4—MP2403 Typical Application Circuit and PCB Layout Guide
MP2403 Rev.1.0
1/21/2020
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MP2403 – 3A, 32V, 250kHz INTEGRATED SYNCHRONOUS STEP-DOWN CONVERTER
PACKAGE INFORMATION
SOIC8N (EXPOSED PAD)
0.229(5.820)
0.244(6.200)
PIN 1 IDENT.
NOTE 4
0.150(3.810)
0.157(4.000)
0.0075(0.191)
0.0098(0.249)
SEE DETAIL "A"
NOTE 2
0.011(0.280) x 45o
0.020(0.508)
0.013(0.330)
0.020(0.508)
0.050(1.270)BSC
0o-8o
NOTE 3
0.189(4.800)
0.197(5.000)
0.053(1.350)
0.068(1.730)
DETAIL "A"
0.016(0.410)
0.050(1.270)
.050
0.049(1.250)
0.060(1.524)
.028
0.200 (5.07 mm)
SEATING PLANE
0.001(0.030)
0.004(0.101)
0.140 (3.55mm)
0.060
Land Pattern
NOTE:
1) Control dimension is in inches. Dimension in bracket is millimeters.
2) Exposed Pad Option (N-Package) ; 2.31mm -2.79mm x 2.79mm - 3.81mm.
Recommend Solder Board Area: 2.80mm x 3.82mm = 10.7mm 2 (16.6 mil2)
3) The length of the package does not include mold flash. Mold flash shall not exceed 0.006in. (0.15mm) per side.
With the mold flash included, over-all length of the package is 0.2087in. (5.3mm) max.
4) The width of the package does not include mold flash. Mold flash shall not exceed 0.10in. (0.25mm) per side.
With the mold flash included, over-all width of the package is 0.177in. (4.5mm) max.
NOTICE: The information in this document is subject to change without notice. Please contact MPS for current specifications.
Users should warrant and guarantee that third party Intellectual Property rights are not infringed upon when integrating MPS
products into any application. MPS will not assume any legal responsibility for any said applications.
MP2403 Rev. 1.0
1/21/2020
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© 2020 MPS. All Rights Reserved.
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