173950378, 173950578
MagI3C Power Module
FDSM Fixed Step Down Regulator Module
we-online.com Würth Elektronik eiSos GmbH & Co. KG Data Sheet Rev. 2.0
© May 2019 1/40
6V – 28V / 500mA / 3.3V or 5V Output
DESCRIPTION
The FDSM series of the MagI3C Power Module family is a
fixed output voltage, fully integrated DC-DC power supply
including the switching regulator, inductor and capacitors
all in one package.
The module requires no external components for
operation, reducing design effort and complexity to a
minimum.
The FDSM ensures fast time to market and low
development costs.
It is pin compatible with the common 78xx linear regulator
series. The high efficiency reduces the power dissipation
and in many cases a heatsink and assembly parts are
unnecessary.
12V to 3.3V conversion achieves up to 85% efficiency.
12V to 5V conversion achieves up to 90% efficiency.
The standard THT (10.5 x 11.6 X 8.5mm) package allows
for easy assembly.
TYPICAL APPLICATIONS
Point-of-Load DC-DC applications from 9V, 12V, 15V,
18V and 24V industrial rails
Replacement for linear regulator
Interface and microcontroller supply
General purpose
TYPICAL CIRCUIT DIAGRAM
FEATURES
Peak efficiency up to 95%
Current capability up to 500mA
Input voltage range: 6V to 28V
Output voltage: 3.3V or 5V
Output voltage accuracy: ± 3% max
No minimum load required
Integrated input and output capacitors
Integrated inductor
Low output voltage ripple (typ 10mVpp)
Fixed 570kHz switching frequency
Current mode control
Pulse skipping for high efficiency at light loads
Internal soft-start
Thermal shutdown
Short circuit protection
Cycle by cycle current limit
Pin compatible with the FDSM power modules series
Operating ambient temperature range: -40°C to 85°C
RoHS & REACh compliant
Case and potting material UL 94 Class V0
(flammability testing) certified
Complies with EN55032 class B conducted and
radiated emissions standard
VIN
GND
VOUT
Module
VIN
GND GND
VOUT
1 3
2
NO NEED FOR COUT
NO NEED FOR CIN
173950378, 173950578
MagI3C Power Module
FDSM Fixed Step Down Regulator Module
we-online.com Würth Elektronik eiSos GmbH & Co. KG Data Sheet Rev. 2.0
© May 2019 2/40
1 2 3
VIN GND VOUT
PACKAGE
MARKING DESCRIPTION
MARKING
DESCRIPTION
WE
Würth Elektronik tradename
78
Indicates the compatibility with 78xx linear regulator
173950X78
Order code
YY
Year
WW
Calendar week
VV
Output voltage (3.3V or 5V)
PIN DESCRIPTION
SYMBOL
PIN
TYPE
DESCRIPTION
VIN
1
Power
The supply input pin is a terminal for an unregulated input voltage
source. There is no need for an external input capacitor.
GND
2
Power
Ground reference for VIN and VOUT
VOUT
3
Power
Regulated output voltage. There is no need for an external output
capacitor.
ORDERING INFORMATION
ORDER CODE
SPECIFICATIONS
PACKAGE
PACKAGING UNIT
173950378
28V / 500mA / 3.3Vout version
SIP-3
Tube with 42 pieces
173950578
28V / 500mA / 5Vout version
SIP-3
Tube with 42 pieces
17800FDSM
4.75 to 42VIN / 3.3 & 5VOUT
Eval Board
1
173950378, 173950578
MagI3C Power Module
FDSM Fixed Step Down Regulator Module
we-online.com Würth Elektronik eiSos GmbH & Co. KG Data Sheet Rev. 2.0
© May 2019 3/40
PIN COMPATIBLE FAMILY MEMBERS
ORDER CODE
SPECIFICATIONS
PACKAGE
PACKAGING UNIT
173010378
28V / 1A / 3.3Vout version
SIP-3
Tube with 42 pieces
173010578
28V / 1A / 5Vout version
SIP-3
Tube with 42 pieces
173010342
42V / 1A / 3.3Vout version
SIP-3
Tube with 42 pieces
173010542
42V / 1A / 5Vout version
SIP-3
Tube with 42 pieces
173950336
36V / 500mA / 3.3Vout version
SIP-3
Tube with 43 pieces
173950536
36V / 500mA / 5Vout version
SIP-3
Tube with 43 pieces
SALES INFORMATION
SALES CONTACTS
Würth Elektronik eiSos GmbH & Co. KG
EMC & Inductive Solutions
Max-Eyth-Str. 1
74638 Waldenburg
Germany
Tel. +49 (0) 7942 945 0
www.we-online.com/powermodules
Technical support: powermodules@we-online.com
173950378, 173950578
MagI3C Power Module
FDSM Fixed Step Down Regulator Module
we-online.com Würth Elektronik eiSos GmbH & Co. KG Data Sheet Rev. 2.0
© May 2019 4/40
ABSOLUTE MAXIMUM RATINGS
Caution:
Exceeding the listed absolute maximum ratings may affect the device negatively and may cause permanent damage. These
are stress ratings only, which do not imply functional operation of the device at these or any other condition beyond those
SYMBOL
PARAMETER
LIMITS
UNIT
MIN (1)
MAX (1)
VIN
Input pin voltage
-0.3
30
V
VOUT
Output pin voltage
-0.6
30
V
Tstorage
Assembled, non-operating storage temperature
-55
125
°C
VESD
ESD Voltage (Human Body Model), according to EN61000-4-2 (2)
-
±2000
V
OPERATING CONDITIONS
Operating conditions are conditions under which operation of the device is intended to be functional. All values are referenced
to GND.
MIN and MAX limits are valid for the recommended ambient temperature range of -40°C to 85°C. Typical values represent
statistically the utmost probable values at the following conditions: VIN = 6V to 28V (173950378), VIN = 7V to 28V (173950578),
IOUT = 500mA(5) , TA = 25°C, unless otherwise specified.
SYMBOL
PARAMETER
MIN (1)
TYP (3)
MAX (1)
UNIT
VIN
Input voltage (173950378)
6
-
28
V
VIN
Input voltage (173950578)
7
-
28
V
TA
Ambient temperature range
-40
-
+85 (4)
°C
IOUT
Nominal output current
-
-
500
mA
COUT MAX
Maximum output capacitor
220
µF
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MagI3C Power Module
FDSM Fixed Step Down Regulator Module
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THERMAL SPECIFICATIONS
SYMBOL
PARAMETER
TYP (3)
UNIT
CA
Case-to-ambient thermal resistance (5)
70
K/W
Tcase max
Maximum case temperature (5)
100
°C
TSD
Thermal shutdown, junction temperature rising
165
°C
ELECTRICAL SPECIFICATIONS
MIN and MAX limits are valid for the recommended ambient temperature range of -40°C to 85°C. Typical values represent
statistically the utmost probability at the following conditions: VIN = 6V to 28V (173950378), VIN = 7V to 28V (173950578), IOUT
= 500mA(5) , TA = 25°C, unless otherwise specified.
SYMBOL
PARAMETER
TEST CONDITIONS
MIN (1)
TYP (3)
MAX (1)
UNIT
Output current
ICL
Current limit threshold
VIN = 12V
2.3
3.5
5.3
A
Output voltage
VOUT
Regulated output voltage
173950378
3.201
3.3
3.399
V
Regulated output voltage
173950578
4.850
5
5.150
V
Line regulation
IOUT = 5mA to 500mA
-
-
±0.5
%
Load regulation
10% to 100% Load
-
-
±1
%
Total output voltage variation
TA = 25°C, IOUT = 500mA
-
-
±3
%
Output voltage ripple
VOUT = 3.3V, IOUT = 500mA
COUT = 10µF X5R, 20MHz BWL
-
10
-
mVpp
VOUT = 5V, IOUT = 500mA
COUT = 10µF X5R, 20MHz BWL
-
10
-
mVpp
Switching frequency
fSW
Switching frequency
VIN = 12V, Continuous
Conduction Mode (CCM)
400
570
740
kHz
Input current
IIN
No load input current
Operating, switching
-
1.5
-
mA
Efficiency
Efficiency
VIN = 6V, VOUT = 3.3V
-
91
-
%
VIN = 28V, VOUT = 3.3V
-
77
-
%
VIN = 7V, VOUT = 5V
-
95
-
%
VIN = 28V, VOUT = 5V
-
83
-
%
RELIABILITY
SYMBOL
PARAMETER
TEST CONDITIONS
TYP (3)
UNIT
MTBF (6)
Mean Time Between Failures
MIL-HDBK-217F, +25°C
4185 · 103
h
MTBF (6)
Mean Time Between Failures
MIL-HDBT-217F, +70°C
2182 · 103
h
173950378, 173950578
MagI3C Power Module
FDSM Fixed Step Down Regulator Module
we-online.com Würth Elektronik eiSos GmbH & Co. KG Data Sheet Rev. 2.0
© May 2019 6/40
RoHS, REACh
RoHS
Directive
Directive 2011/65/EU of the European Parliament and the
Council of June 8th, 2011 on the restriction of the use of certain
hazardous substances in electrical and electronic equipment.
REACh
Directive
Directive 1907/2006/EU of the European Parliament and the
Council of June 1st, 2007 regarding the Registration,
Evaluation, Authorisation and Restriction of Chemicals
(REACh)
PACKAGE SPECIFICATIONS
ITEM
PARAMETER
TYP (3)
UNIT
Case
Non-conductive black plastic, UL94V-0
-
-
Potting material
Silicone, UL94V-0
-
-
Weight
-
2
g
NOTES
(1) Min and Max limits are 100% production tested at 25°C. Limits over the operating temperature range are guaranteed
through correlation using Statistical Quality Control (SQC) methods.
(2) The human body model is a -
22-114.
(3) Typical numbers are valid at 25°C ambient temperature and represent statistically the utmost probability assuming the
Gaussian distribution.
(4) Depending on load current, see derating diagram.
(5) Measured without heatsink, no airflow.
(6) MIL-HDBK-217F; GB Ground, Benign: Non mobile, temperature and humidity controlled environments readily accessible
to maintenance; includes laboratory instruments and test equipment, medical electronic equipment, business and
scientific computer complexes, and missiles and support equipment in ground silos.
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MagI3C Power Module
FDSM Fixed Step Down Regulator Module
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© May 2019 7/40
TYPICAL PERFORMANCE CURVES
If not otherwise specified, the following conditions apply: VIN = 24V; VOUT = 3.3V (173950378) & 5V (173950578); IOUT = 500mA;
TAMB = 25°C.
RADIATED AND CONDUCTED EMISSIONS (WITH EMI INPUT FILTER)
The 173950378 & 173950578 power modules are tested with two EMC configurations (long and short wires between the
module and the load) to give more realistic information about implementation in the applications. The test setup is based on
CISPR16 with the limit values CISPR32.
FILTER SETUP
Input wire length:
Radiated Emission: 160cm (80cm Horizontal + 80cm Vertical)
Conducted Emission: 80cm
Output wire length (Radiated & Conducted):
Short wire: less than 15cm
Long wire: 1m
173950378, 173950578
MagI3C Power Module
FDSM Fixed Step Down Regulator Module
we-online.com Würth Elektronik eiSos GmbH & Co. KG Data Sheet Rev. 2.0
© May 2019 8/40
SHORT WIRE (15cm): 3.3VOUT
0
10
20
30
40
50
60
70
30 100 1000
Frequency [MHz]
Radiated Emissions [dBµV/m]
Radiated Emissions 173950378 (3m Antenna Distance)
VIN = 24V, VOUT = 3.3V, ILOAD = 0.5A with input filter CF & CIN = 4.7µF (885012208094), LF = 10µH (74477310)
Horizontal Vertical
EN55032 Class A limit
EN55032 Class B limit
0
10
20
30
40
50
60
70
0.15 110
Frequency [MHz]
Conducted Emissions [dBµV]
Conducted Emissions 173950378
VIN = 24V, VOUT = 3.3V, ILOAD = 0.5A with input filter CF & CIN = 4.7µF (885012208094), LF = 10µH (74477310)
Average Quasi peak
EN55032 Class B Quasi Peak limit
EN55032 Class B Average limit
80
-10 300.5
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MagI3C Power Module
FDSM Fixed Step Down Regulator Module
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LONG WIRE (1m): 3.3VOUT
0
10
20
30
40
50
60
70
30 100 1000
Frequency [MHz]
Radiated Emissions [dBµV/m]
Radiated Emissions 173950378 (3m Antenna Distance)
VIN = 24V, VOUT = 3.3V, ILOAD = 0.5A with input filter CF & CIN = 4.7µF (885012208094), LF = 10µH (74477310)
and CMC = 1000µH (744222)
Horizontal Vertical
EN55032 Class A limit
EN55032 Class B limit
0
10
20
30
40
50
60
70
0.15 110
Frequency [MHz]
Conducted Emissions [dBµV]
Conducted Emissions 173950378
VIN = 24V, VOUT = 3.3V, ILOAD = 0.5A with input filter CF & CIN = 4.7µF (885012208094), LF = 10µH (74477310)
and CMC = 1000µH (744222)
Average Quasi peak
EN55032 Class B Quasi Peak limit
EN55032 Class B Average limit
80
-10 300.5
173950378, 173950578
MagI3C Power Module
FDSM Fixed Step Down Regulator Module
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© May 2019 10/40
SHORT WIRE (15cm): 5VOUT
0
10
20
30
40
50
60
70
30 100 1000
Frequency [MHz]
Radiated Emissions [dBµV/m]
Radiated Emissions 173950578 (3m Antenna Distance)
VIN = 24V, VOUT = 5V, ILOAD = 0.5A with input filter CF & CIN = 4.7µF (885012208094), LF = 10µH (74477310)
Horizontal Vertical
EN55032 Class A limit
EN55032 Class B limit
0
10
20
30
40
50
60
70
0.15 110
Frequency [MHz]
Conducted Emissions [dBµV]
Conducted Emissions 173950578
VIN = 24V, VOUT = 5V, ILOAD = 0.5A with input filter CF & CIN = 4.7µF (885012208094), LF = 10µH (74477310)
Average Quasi peak
EN55032 Class B Quasi Peak limit
EN55032 Class B Average limit
80
-10 300.5
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MagI3C Power Module
FDSM Fixed Step Down Regulator Module
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LONG WIRE (1m): 5VOUT
0
10
20
30
40
50
60
70
30 100 1000
Frequency [MHz]
Radiated Emissions [dBµV/m]
Radiated Emissions 173950578 (3m Antenna Distance)
VIN = 24V, VOUT = 5V, ILOAD = 0.5A with input filter CF & CIN = 4.7µF (885012208094), LF = 10µH (74477310)
and CMC = 1000µH (744222)
Horizontal Vertical
EN55032 Class A limit
EN55032 Class B limit
0
10
20
30
40
50
60
70
0.15 110
Frequency [MHz]
Conducted Emissions [dBµV]
Conducted Emissions 173950578
VIN = 24V, VOUT = 5V, ILOAD = 0.5A with input filter CF & CIN = 4.7µF (885012208094), LF = 10µH (74477310)
and CMC = 1000µH (744222)
Average Quasi peak
EN55032 Class B Quasi Peak limit
EN55032 Class B Average limit
80
-10 300.5
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MagI3C Power Module
FDSM Fixed Step Down Regulator Module
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EFFICIENCY
0
10
20
30
40
50
60
70
80
90
100
0 0.1 0.2 0.3 0.4 0.5
Efficiency [%]
Output Current [A]
173950378 VOUT = 3.3V, fSW =570kHz, TA = 25C
Vin = 6V
Vin = 9V
Vin = 12V
Vin = 15V
Vin = 18V
Vin = 24V
0
10
20
30
40
50
60
70
80
90
100
0 0.1 0.2 0.3 0.4 0.5
Efficiency [%]
Output Current [A]
173950378 VOUT = 3.3V, fSW =570kHz, TA = 85C
Vin = 6V
Vin = 9V
Vin = 12V
Vin = 15V
Vin = 18V
Vin = 24V
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MagI3C Power Module
FDSM Fixed Step Down Regulator Module
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EFFICIENCY
0
10
20
30
40
50
60
70
80
90
100
0 0.1 0.2 0.3 0.4 0.5
Efficiency [%]
Output Current [A]
173950578 VOUT = 5V, fSW =570kHz, TA = 25C
Vin = 7V
Vin = 9V
Vin = 12V
Vin = 15V
Vin = 18V
Vin = 24V
0
10
20
30
40
50
60
70
80
90
100
0 0.1 0.2 0.3 0.4 0.5
Efficiency [%]
Output Current [A]
173950578 VOUT = 5V, fSW =570kHz, TA = 85C
Vin = 7V
Vin = 9V
Vin = 12V
Vin = 15V
Vin = 18V
Vin = 24V
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FDSM Fixed Step Down Regulator Module
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POWER DISSIPATION
0
0.1
0.2
0.3
0.4
0.5
0 0.1 0.2 0.3 0.4 0.5
Power Dissipation [W]
Output Current [A]
173950378 VOUT = 3.3V, fSW =570kHz, TA = 25C
Vin = 6V
Vin = 9V
Vin = 12V
Vin = 15V
Vin = 18V
Vin = 24V
0
0.1
0.2
0.3
0.4
0.5
0.6
0 0.1 0.2 0.3 0.4 0.5
Power Dissipation [W]
Output Current [A]
173950378 VOUT = 3.3V, fSW =570kHz, TA = 85C
Vin = 6V
Vin = 9V
Vin = 12V
Vin = 15V
Vin = 18V
Vin = 24V
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MagI3C Power Module
FDSM Fixed Step Down Regulator Module
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POWER DISSIPATION
0
0.1
0.2
0.3
0.4
0.5
0 0.1 0.2 0.3 0.4 0.5
Power Dissipation [W]
Output Current [A]
173950578 VOUT = 5V, fSW =570kHz, TA = 25C
Vin = 7V
Vin = 9V
Vin = 12V
Vin = 15V
Vin = 18V
Vin = 24V
0
0.1
0.2
0.3
0.4
0.5
0.6
0 0.1 0.2 0.3 0.4 0.5
Power Dissipation [W]
Output Current [A]
173950578 VOUT = 5V, fSW =570kHz, TA = 85C
Vin = 7V
Vin = 9V
Vin = 12V
Vin = 15V
Vin = 18V
Vin = 24V
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FDSM Fixed Step Down Regulator Module
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OUTPUT POWER DERATING
0
20
40
60
80
100
120
010 20 30 40 50 60 70 80 90 100
Output Power [%]
Ambient Temperature [C]
173950x78 Output Power Thermal Derating
VIN = 24V, IOUT = 500mA & fSW = 570kHz
70C
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FDSM Fixed Step Down Regulator Module
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LINE REGULATION
3.295
3.3
3.305
3.31
3.315
3.32
3.325
510 15 20 25 30
Output Voltage [V]
Input Voltage [V]
173950378 Line Regulation VOUT = 3.3V, TA = 25C
10% Load
100% Load
5.05
5.055
5.06
5.065
5.07
5.075
5.08
510 15 20 25 30
Output Voltage [V]
Input Voltage [V]
173950578 Line Regulation VOUT = 5V, TA = 25C
10% Load
100% Load
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FDSM Fixed Step Down Regulator Module
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LINE REGULATION
3.35
3.36
3.37
3.38
3.39
3.4
3.41
3.42
3.43
3.44
3.45
510 15 20 25 30
Output Voltage [V]
Input Voltage [V]
173950378 Line Regulation VOUT = 3.3V, TA = 85C
10% Load
100% Load
5.1
5.12
5.14
5.16
5.18
5.2
5.22
5.24
5.26
5.28
510 15 20 25 30
Output Voltage [V]
Input Voltage [V]
173950578 Line Regulation VOUT = 5V, TA = 85C
10% Load
100% Load
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MagI3C Power Module
FDSM Fixed Step Down Regulator Module
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LOAD REGULATION
3.295
3.3
3.305
3.31
3.315
3.32
3.325
3.33
3.335
3.34
0 0.1 0.2 0.3 0.4 0.5
Output Voltage [V]
Output Current [A]
173950378 Load Regulation VOUT = 3.3V, TA= 25C
Vin = 9V
Vin = 12V
Vin = 15V
Vin = 18V
Vin = 24V
3.35
3.36
3.37
3.38
3.39
3.4
3.41
3.42
3.43
3.44
0 0.1 0.2 0.3 0.4 0.5
Output Voltage [V]
Output Current [A]
173950378 Load Regulation VOUT = 3.3V, TA= 85C
Vin = 9V
Vin = 12V
Vin = 15V
Vin = 18V
Vin = 24V
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MagI3C Power Module
FDSM Fixed Step Down Regulator Module
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LOAD REGULATION
4.98
4.985
4.99
4.995
5
5.005
5.01
5.015
0 0.1 0.2 0.3 0.4 0.5
Output Voltage [V]
Output Current [A]
173950578 Load Regulation VOUT = 5V, TA= 25C
Vin = 9V
Vin = 12V
Vin = 15V
Vin = 18V
Vin = 24V
5.05
5.1
5.15
5.2
5.25
5.3
5.35
5.4
5.45
5.5
0 0.1 0.2 0.3 0.4 0.5
Output Voltage [V]
Output Current [A]
173950578 Load Regulation VOUT = 5V, TA= 85C
Vin = 9V
Vin = 12V
Vin = 15V
Vin = 18V
Vin = 24V
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MagI3C Power Module
FDSM Fixed Step Down Regulator Module
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BLOCK DIAGRAM
VOUT
PWM Controller
Driver
Protection Circuitry
1
COUT
VOUT
VIN
UVLO
CIN
VIN
33µH
VREF
GND
0.8V
Power Module
Error Amplifier
3
2GND
CBoot
CSS
RFBT
RFBB
1 µF 22 µF
PGND PGND
VIN
CIRCUIT DESCRIPTION
The MagI³C power modules 173950x78 are based on a non-synchronous step-down regulator with integrated MOSFET, free-
wheeling diode, power inductor, input and output capacitors. The control scheme is based on a Current Mode (CM) regulation
loop.
The VOUT of the regulator is divided with the internal feedback resistor network and fed into the error amplifier, which compares
this signal with the internal 0.8V reference. The error signal is amplified and controls the on-time of a fixed frequency pulse
width generator. This signal drives the MOSFET.
The Current Mode architecture features a constant frequency during load steps. Only the on-time is modulated. It is internally
compensated and stable with low ESR output capacitors. No external compensation network is required.
This architecture supports fast transient response and very small output voltage ripple values (typ. 10mV) are achieved.
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OUTPUT VOLTAGE RIPPLE
The output voltage ripple depends on several parameters. The figure below shows the VOUT ripple at full load and using a
10µF MLCC output capacitor. An output voltage ripple of around 10mV is measured under the conditions indicated.
3.360
3.365
3.370
3.375
3.380
3.385
3.390
3.395
3.400
010 20 30 40 50 60
Output Voltage [V]
Time [µs]
173950378 Output Voltage Ripple, VIN = 12V, VOUT = 3.3V & IOUT = 500mA
9mV
5.080
5.085
5.090
5.095
5.100
5.105
5.110
5.115
010 20 30 40 50 60
Output Voltage [V]
Time [µs]
173950578 Output Voltage Ripple, VIN = 12V, VOUT = 5V & IOUT = 500mA
10mV
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LIGHT LOAD OPERATION
Under light load operation, the device switches from Continuous Conduction Mode (CCM) to Discontinuous Conduction Mode
(DCM). The load current where the transition between DCM and CCM takes place can be estimated using the following
formula:
(1)
The figures below show the device working in CCM and DCM.
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0 2 4 6 8 10
Inductor Current [IL]
Time [µs]
173950x78 Inductor Ripple Current VIN = 24V & IOUT = 500mA
CCM Operation
1.76µs 570KHz
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0 2 4 6 8 10
Inductor Current [IL]
Time [µs]
173950x78 Inductor Ripple Current VIN = 24V & IOUT = 200mA
CCM Operation
1.81µs 552kHz
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If the load current is further reduced, the device increases the OFF-Time by reducing the switching frequency in order to limit
the energy transferred to the output (to both capacitor and load) and therefore keeping the output voltage regulated. The
increase in OFF-Time is shown in the figures below.
-0.2
-0.1
0.0
0.1
0.2
0.3
0.4
0 2 4 6 8 10
Inductor Current [IL]
Time [µs]
173950x78 Inductor Ripple Current VIN = 24V & IOUT = 50mA
DCM Operation
1.9µs 526kHz
-0.2
-0.1
0.0
0.1
0.2
0.3
0 2 4 6 8 10
Inductor Current [IL]
Time [µs]
173950x78 Inductor Ripple Current VIN = 24V & IOUT = 10mA
DCM Operation
1.93µs 518kHz
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SOFT-START
In order to prevent the output voltage from overshooting during start-up, a soft-start is implemented. The soft-start is internally
set for both the 173950378 and 173950578. The figures below show the start-up behavior of the power module with 3.3V and
5V output voltage respectively.
0
2
4
6
8
10
12
14
020 40 60 80 100 120
VIN & VOUT [V]
Time [ms]
173950378 Soft Start, VIN = 12V, VOUT = 3.3V & IOUT = 500mA
Input Voltage
Output
Soft Start
0
2
4
6
8
10
12
14
020 40 60 80 100 120
VIN & VOUT [V]
Time [ms]
173950578 Soft Start, VIN = 12V, VOUT = 5V & IOUT = 500mA
Input Voltage
Output Voltage
Soft Start
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PROTECTIVE FEATURES
Over temperature protection (OTP)
Thermal protection helps prevent catastrophic failures due to accidental device overheating. The junction temperature of the
MagI³C Power Module should not be allowed to exceed its maximum ratings. Thermal protection is implemented by an internal
thermal shutdown circuit which activates at 165°C (typ.), causing the device to enter a low power standby state. In this state
the MOSFET remains off causing VOUT to fall. Thermal protection helps to prevent catastrophic failures from accidental device
overheating. When the junction temperature falls back below 165° (hysteresis is implemented) VOUT rises smoothly and normal
operation resumes.
Short circuit protection (SCP)
The short circuit protection is realized via cycle by cycle current monitoring. Recovery from short circuit protection mode occurs
during the switching cycle following the removal of the short circuit condition. When the 173950x78 recovers from a short
circuit condition, the soft-start is not active. Therefore an overshoot at output voltage can be observed (see figure below).
Under short circuit condition the input current is limited.
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
0.0 0.2 0.4 0.6 0.8 1.0
Output Voltage [V]
Time [s]
173950378 Short Circuit Protection, VIN = 24V, VOUT = 3.3V & IOUT = 500mA
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0.0
1.0
2.0
3.0
4.0
5.0
6.0
0.0 0.2 0.4 0.6 0.8 1.0
Output Voltage [V]
Time [s]
173950578 Short Circuit Protection, VIN = 24V, VOUT = 5V, IOUT = 500mA
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Over current protection (OCP)
For protection against load faults, the 173950x78 incorporates cycle-by-cycle current monitoring. During an overcurrent
condition the output current is limited and the output voltage drops. When the overcurrent condition is removed, the output
voltage returns to the nominal voltage.
0.0
0.4
0.8
1.2
1.6
2.0
2.4
0.0
1.0
2.0
3.0
4.0
5.0
6.0
0246810 12 14 16 18 20
Output Current [A]
Output Voltage [V]
Time [s]
173950378 Overcurrent Protection, VIN = 24V, TA= 25C
Output Voltage
Output Current
0.0
0.4
0.8
1.2
1.6
2.0
2.4
0.0
1.0
2.0
3.0
4.0
5.0
6.0
0 2 4 6 8 10 12 14 16 18 20
Output Current [A]
Output Voltage [V]
Time [s]
173950578 Overcurrent Protection, VIN = 24V, TA= 25C
Output Voltage
Output Current
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Over voltage protection (OVP)
This protection feature minimizes the occurrence of output voltage over shooting. In the case of an output voltage transient,
that reaches the overvoltage threshold, the switching will be stopped by the high side MOSFET, reducing the inductor current
to zero. When the output voltage falls below the threshold, the high side MOSFET is again enabled thus increasing the inductor
current.
The figure below shows an example, in which it can be seen how the inductor current is reduced to zero when an over voltage
transient is detected at the feedback node.
-100
0
100
200
300
400
500
600
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
0.00 0.02 0.04 0.06 0.08 0.10 0.12 0.14 0.16 0.18 0.20
Inductor Current IL[mA]
Feedback Voltage VFB [V]
Time [ms]
173950x78 Overvoltage Protection IOUT = 500mA, TA= 25C
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EVALUATION BOARD SCHEMATIC (17800FDSM v.1.0)
VIN
GND
VOUT
Module
1
2
3
C2
VIN
Cf
R1
GND
+
C1 C3
VOUT
C4
GND
+
Optional input filter OptionalOptional
Lf
The 17950x78 integrates both the input and output capacitors. Therefore, additional external input/output capacitors are
normally not required.
The additional 100µF aluminum electrolytic capacitor C1 is mounted as termination of the supply line and provides a slight
damping of possible oscillations of the series resonance circuit represented by the inductance of the supply line and the input
capacitance. This capacitor also prevents voltage overshoot during start up.
The additional MLCC Cf is part of the input filter and is not mounted on the board. The inductor Lf is not mounted too (see
recommended part number in the table below). A zero ohm resistor (R1) is mounted in parallel with Lf. In case the input filter
is placed, R1 must be removed and an appropriate Lf mounted.
Although the 17950x78 do not need any external output capacitor, in case particular application requirements are demanding
additional capacitance, the evaluation board gives the possibility to place further capacitors at the output: C3 (MLCC). This
capacitor allows fine tuning of load transient voltage response.
Bill of Material
Designator
Description
Quantity
Order Code
Manufacturer
IC1
MagI3C Power Module (not mounted)
1
171950x78
Würth Elektronik
C1
Aluminum electrolytic capacitor, ATG5 family, 100F/50V
1
860010674014
Würth Elektronik
C2
Ceramic chip capacitor, 4.7µF/50V/X7R, 0805 (not
mounted)
optional
885012208094
Würth Elektronik
C3
Ceramic chip capacitor (not mounted)
optional
C4
Surface mounted electrolytic, WCAP-PSLP 220µF/10V
1
875105244013
Würth Elektronik
Cf
Ceramic chip capacitor 1µF/50V X7R, 0805 (not
mounted)
optional
885012108021
Würth Elektronik
Lf
Filter inductor, 22µH, PD2 (not mounted)
optional
744774122
Würth Elektronik
R1
1
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Filter suggestion for conducted EMI
The input filter shown in the schematic below is recommended to achieve conducted compliance according to EN55032
CISPR32 Class B (see results on page 7).
For radiated EMI the input filter is not necessary. It is only used to comply with the setup recommended in the norms.
FILTER SETUP: SHORT WIRE:
C2
VIN
Cf
Input LC Filter
RLoad
15cm wire
VIN
GND
VOUT
Module
1
2
3
+
C1
GND
Lf
Bill of Material of the Input LC Filter (VIN = 24V, VOUT = 3.3V & 5V, IOUT = 500mA)
Designator
Description
Order Code
Manufacturer
C2
Filter MLCC capacitor 4.7µF/50V/X7R
885012208094
Würth Elektronik
Cf
Filter MLCC capacitor 4.7µF/50V/X7R
885012208094
Würth Elektronik
Lf
Filter inductor, 10µH, PD2 family, ISAT = 1.74A , IR = 1.45A
74477310
Würth Elektronik
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FILTER SETUP: LONG WIRE:
C2
VIN
Cf
Input LC Filter
RLo ad
1m wire
VIN
GND
VOUT
Module
1
2
3
CMC
+
C1
GND
Lf
Bill of Material of the Input LC Filter (VIN = 24V, VOUT = 3.3V & 5V, IOUT = 500mA)
Designator
Description
Order Code
Manufacturer
C2
Filter MLCC capacitor 4.7µF/50V/X7R
885012208094
Würth Elektronik
Cf
Filter MLCC capacitor 4.7µF/50V/X7R
885012208094
Würth Elektronik
Lf
Filter inductor, 10µH, PD2 family, ISAT = 1.74A , IR = 1.45A
74477310
Würth Elektronik
CMC
Common Mode Choke, 1000µH, SL2 family
744222
Würth Elektronik
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Generating negative output voltage
Many industrial applications require negative voltages. The 173950x78 can easily provide a negative voltage using the circuit
shown below.
VIN GND
VOUT
1 2
3
GND
VOUT-
173950x78
CIN
VIN
GND
10µF
It is important to be aware that in this configuration the 173950x78 must withstand the sum of the input voltage and the absolute
value of the output voltage (VIN + |VOUT|), instead of just the input voltage. This means that the maximum operating voltage
should be limited to 28V - |VOUT| (e.g. if the 171950578 is used in this configuration, the input voltage should not exceed 23V).
Moreover, the maximum output current of this configuration is no longer 0.5A, instead it must be reduced according to the
below mentioned formula (see also the graph below):
where D is the duty cycle, in this case defined according to:
Starting Condition for generating negative output voltage:
VIN_MIN = 4.75V (3.3VOUT) & 6.5V (5 VOUT)
IOUT_MIN = 20mA (3.3 & 5VOUT)
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Compared with a standard positive buck configuration, the negative output buck contains an additional critical loop (between
VIN and VOUT), which needs an additional capacitor CIN, as shown in the circuit above.
0
0.1
0.2
0.3
0.4
0.5
0 5 10 15 20 25
Output Current [A]
Input Voltage [V]
Output Current of the Negative Output Configuration
Vout = 3.3V
Vout = 5V
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Generating complementary output voltage
Another common requirement in industrial application is to provide a complementary voltage (e.g. ±5V). The circuit below
shows how this target can be achieved simply combining a 173950x78 used in a standard configuration (delivering a positive
output voltage) with the above mentioned solution for negative voltages.
VIN GND
VOUT
1 2
3
GND
VOUT-
173950x78
CIN
VIN
GND
10µF
VIN VOUT
GND
1 3
2
VOUT
173950x78
GND
Complementary output voltage
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WAVE SOLDER PROFILE
Profile Feature
Old standard (Pb)
New (Pb-free)
Time within peak temperature tP
10 s
10 s
Average ramp-up rate
~ 200 °C/s
~ 200 °C/s
Final preheat temperature Ts
~ 130 °C
~ 130 °C
Peak temperature TP
+ 235 °C
+ 260 °C
Ramp-down rate
-5 °C/s
-5 °C/s
Heating rate during preheat
4 °C/s
4 °C/s
Wave Solder Diagram:
Temperature [°C]
Time [sec]
25
First wave
Second wave
tP
TS
TP
preheat ramp down
3 – 5 s
5°C/s
200°C/s
130
4°C/s
235
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PHYSICAL DIMENSIONS
Tolerance: xx.x = ±0.5mm ; xx.xx = ±0.25mm
RECOMMENDED DRILL HOLES TUBE
all dimensions in mm
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DOCUMENT HISTORY
Revision
Date
Description
Comment
1.0
Dec 2014
Final version
2.0
May 2019
Update version released
Added:
- EMI measurements with different setups
- additional circuit and application description
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CAUTIONS AND WARNINGS
The following conditions apply to all goods within the product series of MagI³C of
Würth Elektronik eiSos GmbH & Co. KG:
General:
-sheet have to be complied with.
harm the component surface has
to be avoided.
-critical or high-reliability applications, should be pre-evaluated by the
customer.
et specified values. If the usage and operation
conditions specified in the datasheet are not met,the component may be damaged or dissolved.
ronik products are qualified according to international standards, which are listed in each product reliability report.
r
its validity and sustainability over time.
s
within the authority of the customer. All technical specifications for standard products also apply to customer specific products.
-related
requirements concerning its products, and any use of Würth Elektronik eiSos GmbH & Co. KG components in its applications,
notwithstanding any applications-related information or support that may be provided by Würth Elektronik eiSos GmbH & Co.
KG. Customer represents and agrees that it has all the necessary expertise to create and implement safeguards which
anticipate dangerous consequences of failures, monitor failures and their consequences lessen the likelihood of failures that
might cause harm and take appropriate remedial actions. Customer will fully indemnify Würth Elektronik eiSos and its
representatives against any damages arising out of the use of any Würth Elektronik eiSos GmbH & Co. KG components in
safety-critical applications.
Product specific:
Follow all instructions mentioned in the datasheet, especially:
comply with the technical reflow or wave soldering specification, otherwise this will void the warranty.
-code.
specifications such as exceeding the absolute maximum ratings will void the warranty.
anual handling and processing by machinery.
of the body, pins or termination. The washing varnish agent could have a negative effect on the long term function of the
product.
in
the worst case it could break. As these devices are sensitive to electrostatic discharge customer shall follow proper IC Handling
Procedures.
DISCLAIMER
This electronic component has been designed and developed for usage in general electronic equipment only. This product is
not authorized for use in equipment where a higher safety standard and reliability standard is especially required or where a
failure of the product is reasonably expected to cause severe personal injury or death, unless the parties have executed an
agreement specifically governing such use.
Moreover Würth Elektronik eiSos GmbH & Co KG products are neither designed nor intended for use in areas such as
military, aerospace, aviation, nuclear control, submarine, transportation (automotive control, train control, ship control),
transportation signal, disaster prevention, medical, public information network etc.. Würth Elektronik eiSos GmbH & Co KG
must be informed about the intent of such usage before the design-in stage. In addition, sufficient reliability evaluation
checks for safety must be performed on every electronic component which is used in electrical circuits that require high
safety and reliability functions or performance.
These cautions and warnings comply with the state of the scientific and technical knowledge and are believed to be accurate
and reliable. However, no responsibility is assumed for inaccuracies or incompleteness.
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IMPORTANT NOTES
The following conditions apply to all goods within the product range of Würth Elektronik eiSos GmbH & Co. KG:
1. General Customer Responsibility
Some goods within the product range of Würth Elektronik eiSos GmbH & Co. KG contain statements regarding general
suitability for certain application areas. These statements about suitability are based on our knowledge and experience of
typical requirements concerning the areas, serve as general guidance and cannot be estimated as binding statements about
the suitability for a customer application. The responsibility for the applicability and use in a particular customer design is
always solely within the authority of the customer. Due to this fact it is up to the customer to evaluate, where appropriate to
investigate and decide whether the device with the specific product characteristics described in the product specification is
valid and suitable for the respective customer application or not. Accordingly, the customer is cautioned to verify that the
datasheet is current before placing orders.
2. Customer Responsibility related to Specific, in particular Safety-Relevant Applications
It has to be clearly pointed out that the possibility of a malfunction of electronic components or failure before the end of the
usual lifetime cannot be completely eliminated in the current state of the art, even if the products are operated within the range
of the specifications. In certain customer applications requiring a very high level of safety and especially in customer
applications in which the malfunction or failure of an electronic component could endanger human life or health it must be
ensured by most advanced technological aid of suitable design of the customer application that no injury or damage is caused
to third parties in the event of malfunction or failure of an electronic component.
3. Best Care and Attention
Any product-specific notes, warnings and cautions must be strictly observed. Any disregard will result in the loss of warranty.
4. Customer Support for Product Specifications
Some products within the product range may contain substances which are subject to restrictions in certain jurisdictions in
order to serve specific technical requirements. Necessary information is available on request. In this case the field sales
engineer or the internal sales person in charge should be contacted who will be happy to support in this matter.
5. Product R&D
Due to constant product improvement product specifications may change from time to time. As a standard reporting procedure
of the Product Change Notification (PCN) according to the JEDEC-Standard we inform about minor and major changes. In
case of further queries regarding the PCN, the field sales engineer or the internal sales person in charge should be contacted.
The basic responsibility of the customer as per Section 1 and 2 remains unaffected.
6. Product Life Cycle
Due to technical progress and economical evaluation we also reserve the right to discontinue production and delivery of
products. As a standard reporting procedure of the Product Termination Notification (PTN) according to the JEDEC-Standard
we will inform at an early stage about inevitable product discontinuance. According to this we cannot guarantee that all products
within our product range will always be available. Therefore it needs to be verified with the field sales engineer or the internal
sales person in charge about the current product availability expectancy before or when the product for application design-in
disposal is considered. The approach named above does not apply in the case of individual agreements deviating from the
foregoing for customer-specific products.
7. Property Rights
All the rights for contractual products produced by Würth Elektronik eiSos GmbH & Co. KG on the basis of ideas, development
contracts as well as models or templates that are subject to copyright, patent or commercial protection supplied to the customer
will remain with Würth Elektronik eiSos GmbH & Co. KG. Würth Elektronik eiSos GmbH & Co. KG does not warrant or represent
that any license, either expressed or implied, is granted under any patent right, copyright, mask work right, or other intellectual
property right relating to any combination, application, or process in which Würth Elektronik eiSos GmbH & Co. KG components
or services are used.
8. General Terms and Conditions
Unless otherwise agreed in individual contracts, all orders are subject to the current versi
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