Electromagnetic Emission Summary of XC2000/XE166 Microcontrollers

XC2000 and XE166 Family
Derivatives / Base Line
Electromagnetic Emission Summary
AP16167
Test Report
V1.0 2009-04
Microcontrollers
Edition 2009-04
Published by
Infineon Technologies AG
81726 Munich, Germany
© 2009 Infineon Technologies AG
All Rights Reserved.
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THIS APPLICATION NOTE.
Information
For further information on technology, delivery terms and conditions and prices, please contact the nearest
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AP16167
Electromagnetic Emission Summary
Revision History: V1.0, 2009-04
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Electromagnetic Emission Summary
XC2000 and XE166 Family Derivatives / Base Line
Table of Contents
1
Introduction ........................................................................................................................................5
2
Emission Measurement Methods .....................................................................................................6
3
Emission Limit Curves ......................................................................................................................8
4
Microcontroller Operation during Test ............................................................................................9
5
Application-Typical Emission Tests ..............................................................................................10
6
Worst-Case Emission Tests............................................................................................................21
7
References ........................................................................................................................................36
8
Executive Summary .........................................................................................................................37
Test Report
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Electromagnetic Emission Summary
XC2000 and XE166 Family Derivatives / Base Line
1
Introduction
This summary describes the electromagnetic emission behaviour of the following microcontroller products:
PG-LQFP-64 package:
XC223xM derivatives
XC233xA derivatives
XC2735X derivatives
XE162xM derivatives
PG-LQFP-100 package:
XC226xM derivatives
XC236xA derivatives
XC2765X derivatives
XE164xM derivatives
PG-LQFP-144 package:
XC228xM derivatives
XC238xA derivatives
XC2785X derivatives
XE167xM derivatives
Slight differences in the electromagnetic emission performance exist between the package versions (PG-LQFP64, 100, 144). The derivatives which come in the same package show similar emission due to the fact that they
contain similar microcontroller designs.
Detailled reports on electromagnetic emission – dedicated to every package version – are available on request
as listed in chapter 7. The detailled reports contain much more information about the test board, the software
settings wrt. module operation, additional probed pins, and comparison with other Infineon 16-bit
microcontrollers.
The following derivatives have been measured as representatives of the different packages to obtain the
electromagnetic emission results found in this summary:
PG-LQFP-64 package:
XC2735X
PG-LQFP-100 package:
XC2361A
PG-LQFP-144 package:
XC2286M
All EMI test results presented in this report are obtained from hardware and software test setups compliant to
the “Generic IC EMC Test Specification” (“BISS paper”), open copyright 2004 by Robert Bosch GmbH, Infineon
Technologies AG, Continental AG (former Siemens-VDO).
All significant emission peaks around 950 MHz are mainly caused by transmitters in the GSM band, and not
caused by microcontroller emission.
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AP16167
Electromagnetic Emission Summary
XC2000 and XE166 Family Derivatives / Base Line
2
Emission Measurement Methods
The setup used for electromagnetic emission measurement complies fully with the BISS test specification which
can be provided on request. One test board was designed for every PG-LQFP package with similar layout. The
test board is used for conducted and radiated emission measurements.
Conducted emission is measured using the standardized 150 Ω network, see figure 1. This network is used for
both port and power supply emission measurements. Only crosstalk noise is measured; i.e. the port pins under
test are never actively switching. Frequency range is 150 kHz to 1 GHz.
Fig. 1 shows the schematic 150 Ω network connection to the microcontroller (IC under test) and the general
layout of each 150 Ω probing net.
Figure 1
150 Ω probing networks for conducted emission measurement
150Ω networks are provided for conducted emission measurements according the international standard IEC
61967 part 4 and the BISS test specification for a set of signals and power supply nets. All digital power supply
nets plus a subset of I/O pins (typically located in the center of all 4 package edges) are measured, see figure 2.
Figure 2
Test Report
Probed supply and signal nets for conducted emission measurement
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Electromagnetic Emission Summary
XC2000 and XE166 Family Derivatives / Base Line
Radiated emission is measured using the standard mini TEM cell according IEC 61967 part 2 and BISS
emission test specification. The frequency range is from 150 kHz to 1 GHz.
Figure 3
Measurement setup for radiated emission
Measurement instrumentation and conditions:
Spectrum analyzer:
Rohde & Schwarz FSP7
Detector type:
Peak detector
Measurement time:
For all measurements, the emission measurement time (10ms) at one
frequency is longer than the test software loop duration.
Pre-Amplifier:
internal
Data generation software:
Rohde & Schwarz EMIPAK 9950
Environment:
temperature 23°C ± 5°C
Supply:
nominal voltage ± 5%
For all measurements the noise floor is at least 6dB below the limit.
Spectrum Analyzer
Frequency range
TEM
150 Ω
RBW
150 kHz
to
30 MHz
30 MHz
to
200 MHz
200 MHz
to
1000 MHz
10kHz
Sweep time*
ts =
NP ⋅ LT ⋅ FR
RBW
*) NP = number of points; LT = loop time; FR = frequency range
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Electromagnetic Emission Summary
XC2000 and XE166 Family Derivatives / Base Line
3
Emission Limit Curves
For reference purpose, all measured emission spectra are enhanced by the “external digital bus systems” limit
curves taken from the BISS specification. Figure 4 introduces these 3 limit curves:
Conducted emission 150 Ω, limit for supply pin emission (Supply Conducted),
•
Conducted emission 150 Ω, limit for port pin emission (I/O Conducted),
•
Radiated emission, limit for Mini TEM cell emission (Radiated).
dBµV
•
80
75
70
65
60
55
50
45
40
35
30
25
20
15
10
5
0
I/O Conducted
Supply Conducted
Radiated
0,1
1,0
10,0
100,0
1000,0
Frequency/MHz
Figure 4
BISS limit curves in logarithmic scale
If the measured emission stays below the respective limit, the measured supply or signal net is treated as
“clean”. If the measured emission violates the respective limit for one or more frequencies, some more care
must be taken for an EMC-friendly PCB layout. Infineon strongly recommends to use all microcontroller
hardware settings provided for reduction of electromagnetic emission (as long as your required system
performance permits):
•
Reduce system clock frequency
•
Disable unused clocks (e.g. CLKOUT [automatically disabled after reset])
•
Reduce output pad driver strength (up to 6 settings available for all port pins) [1]
•
Consider Infineon’s general and product-specific PCB design guidelines which propose optimized
power supply layout and decoupling concept [2] [3]
Test Report
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Electromagnetic Emission Summary
XC2000 and XE166 Family Derivatives / Base Line
4
Microcontroller Operation during Test
To get a realistic impression of the microcontroller’s emission potential, so called “application-typical” settings
have been applied during the tests. This means:
•
CPU and all functional modules are active
•
CLKOUT is disabled
•
High-speed interfaces are active (e.g. SPI @ 5 MBit/s, ASC / LIN / CAN @ 500 kBit/s)
•
Other I/Os operate at lower data rates
•
All output pad driver strengths are selected according their data rates, driving 22pF load. Since most
pins cannot be configured individually, some more pins of the same ports are also forced to stronger
state even if this would be desired only for one or two port pins. This is the ratio in percent of driver
settings (All GPIOs without ADC channels) used for the emission tests:
Driver strength
PG-LQFP-64
PG-LQFP-100
PG-LQFP-144
Weak
57 %
50 %
32 %
Medium
0
0
0
Strong-soft
0
14 %
9%
Strong-medium
0
0
0
Strong-sharp
40 %
34 %
58 %
Extra-strong
3%
2%
1%
•
External memory bus (if available) is not used
•
Execution from on-chip flash memory
In addition, a worst-case operation scenario is measured for reference purpose:
•
CLKOUT is activated for worst-case operation.
•
The external memory bus is never enabled since it is not recommended to be used because of
significant occupation of ports and execution slow-down by wait-states.
The power supply system is in all cases configured as follows:
•
VDDP and VDDP1 supplies are 5.0 V
•
VDDI and VDDIM are supplied by internal voltage regulator
The crystal frequency is 8 MHz in all cases.
Test Report
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Electromagnetic Emission Summary
XC2000 and XE166 Family Derivatives / Base Line
5
Application-Typical Emission Tests
General remarks:
The microcontroller is running in “application-typical” mode. The general hardware settings are described in
chapter 4.
The I/O supply voltage VDDP is set to 5.0 V.
Any emission peaks rising from lower noise floor in the 900 MHz range result from GSM transmitters and are
not related to microcontroller operation.
Summary of emission behaviour in application-typical operating mode:
1) VDDI reflects the emission resulting from the core clock tree, i.e. the harmonics are multiples of the
system clock frequency. However, since all measured microcontroller derivatives use an internal volage
regulator, the VDDI net has no connection to an external voltage regulator. The only component
connected to VDDI is the decoupling capacitor. Thus no effective antenna structure to radiate emission
from VDDI should be provided on the PCB, and theVDDI emission should not be system-relevant.
2) Both power supplies VDDI and VDDP show highest emission on the smallest device (PG-LQFP-64).
Reason is that this package provides no e-pad for central VSS solder connection. From this result, it is
advisable to solder the VSS e-pad when using PG-LQFP-100 and PG-LQFP-144 devices to reduce
emission.
3) Core noise coupling from VDDI to VDDP is efficiently suppressed in PG-LQFP-100 and PG-LQFP-144
devices, but some coupling happens on the PG-LQFP-64 package which is again due to the missing
VSS e-pad, which connects all VSS pins (from core and I/O domain) with very low impedance and thus
offers a better common reference point for the VDDI and VDDP noise.
4) I/O emission is – in contrast to supply emission – visible up to 1 GHz. Reason is that there is no
available on-chip space to design decoupling capacitors for the VDDP system. Also I/O pins cannot be
decoupled on chip nor on PCB. This is the reason why the BISS limit curve for I/O emission is defined
10 dB above the supply limit curve. Please note that all I/O pins where emission is measured are
inactive (i.e. not switching) pads which are set to state “output low”. From the emission shape, special
care on PCB layout might be necessary to prevent I/O noise from being coupled to any antenna
structures on the PCB. Advisable PCB layout rules are:
a. Keep signal traces short
b. Route signal traces as micro-strip or stripline (ground shielding)
c.
Avoid signal trace vias through power or ground planes
d. Use lowest permissable data rates
e. Use weakest permissable pad driver settings
For further recommendations please refer to Infineon’s application notes listed in chapter 7.
5) Summarized, the emissions of all package versions stay below the BISS limits and thus should not
cause any severe problems for low-emission PCB design. More care on power routing and noise
decoupling should be taken for PG-LQFP-64 derivatives.
6) Radiated emission stays far below BISS limits – there is no indication of any significant direct radiation
from chip or package, independent from the package size.
7) The part of conducted and radiated emission which is caused by switching I/O noise will decrease when
the VDDP voltage is lowered from 5.0 V to 3.3 V. In this case emission peaks may be reduced by ca.
6 dB.
Test Report
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Electromagnetic Emission Summary
XC2000 and XE166 Family Derivatives / Base Line
Application-typical conducted emission on core supply net VDDI; system clock is 20 MHz.
PG-LQFP-64 CE VDDI 20MHz APP
60
55
50
45
40
dBµV
35
30
25
20
15
10
5
0
0
100
200
300
400
500
600
700
800
900
1000
Frequency/MHz
Figure 5
PG-LQFP-64; Application; VDDI conducted; 20 MHz
PG-LQFP-100 CE VDDI 20MHz APP
60
55
50
45
40
dBµV
35
30
25
20
15
10
5
0
0
100
200
300
400
500
600
700
800
900
1000
Frequency/MHz
Figure 6
PG-LQFP-100; Application; VDDI conducted; 20 MHz
PG-LQFP-144 CE VDDI 20MHz APP
60
55
50
45
40
dBµV
35
30
25
20
15
10
5
0
0
100
200
300
400
500
600
700
800
900
1000
Frequency/MHz
Figure 7
Test Report
PG-LQFP-144; Application; VDDI conducted; 20 MHz
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Electromagnetic Emission Summary
XC2000 and XE166 Family Derivatives / Base Line
Application-typical conducted emission on core supply net VDDI; system clock is 80 MHz.
PG-LQFP-64 CE VDDI 80MHz APP
60
55
50
45
40
dBµV
35
30
25
20
15
10
5
0
0
100
200
300
400
500
600
700
800
900
1000
Frequency/MHz
Figure 8
PG-LQFP-64; Application; VDDI conducted; 80 MHz
PG-LQFP-100 CE VDDI 80MHz APP
60
55
50
45
40
dBµV
35
30
25
20
15
10
5
0
0
100
200
300
400
500
600
700
800
900
1000
Frequency/MHz
Figure 9
PG-LQFP-100; Application; VDDI conducted; 80 MHz
PG-LQFP-144 CE VDDI 80MHz APP
60
55
50
45
40
dBµV
35
30
25
20
15
10
5
0
0
100
200
300
400
500
600
700
800
900
1000
Frequency/MHz
Figure 10
Test Report
PG-LQFP-144; Application; VDDI conducted; 80 MHz
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Electromagnetic Emission Summary
XC2000 and XE166 Family Derivatives / Base Line
Application-typical conducted emission on I/O supply net VDDP; system clock is 20 MHz.
PG-LQFP-64 CE VDDP 20MHz APP
60
55
50
45
40
dBµV
35
30
25
20
15
10
5
0
0
100
200
300
400
500
600
700
800
900
1000
Frequency/MHz
Figure 11
PG-LQFP-64; Application; VDDP conducted; 20 MHz
PG-LQFP-100 CE VDDP 20MHz APP
60
55
50
45
40
dBµV
35
30
25
20
15
10
5
0
0
100
200
300
400
500
600
700
800
900
1000
Frequency/MHz
Figure 12
PG-LQFP-100; Application; VDDP conducted; 20 MHz
PG-LQFP-144 CE VDDP 20MHz APP
60
55
50
45
40
dBµV
35
30
25
20
15
10
5
0
0
100
200
300
400
500
600
700
800
900
1000
Frequency/MHz
Figure 13
Test Report
PG-LQFP-144; Application; VDDP conducted; 20 MHz
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Electromagnetic Emission Summary
XC2000 and XE166 Family Derivatives / Base Line
Application-typical conducted emission on I/O supply net VDDP; system clock is 80 MHz.
PG-LQFP-64 CE VDDP 80MHz APP
60
55
50
45
40
dBµV
35
30
25
20
15
10
5
0
0
100
200
300
400
500
600
700
800
900
1000
Frequency/MHz
Figure 14
PG-LQFP-64; Application; VDDP conducted; 80 MHz
PG-LQFP-100 CE VDDP 80MHz APP
60
55
50
45
40
dBµV
35
30
25
20
15
10
5
0
0
100
200
300
400
500
600
700
800
900
1000
Frequency/MHz
Figure 15
PG-LQFP-100; Application; VDDP conducted; 80 MHz
PG-LQFP-144 CE VDDP 80MHz APP
60
55
50
45
40
dBµV
35
30
25
20
15
10
5
0
0
100
200
300
400
500
600
700
800
900
1000
Frequency/MHz
Figure 16
Test Report
PG-LQFP-144; Application; VDDP conducted; 80 MHz
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Electromagnetic Emission Summary
XC2000 and XE166 Family Derivatives / Base Line
Application-typical conducted emission on I/O net at upper package edge; system clock is 20 MHz.
PG-LQFP-64 CE P10.14 20MHz APP
60
55
50
45
40
dBµV
35
30
25
20
15
10
5
0
0
100
200
300
400
500
600
700
800
900
1000
Frequency/MHz
Figure 17
PG-LQFP-64; Application; P10.14 conducted; 20 MHz
PG-LQFP-100 CE P1.4 20MHz APP
60
55
50
45
40
dBµV
35
30
25
20
15
10
5
0
0
100
200
300
400
500
600
700
800
900
1000
Frequency/MHz
Figure 18
PG-LQFP-100; Application; P1.4 conducted; 20 MHz
PG-LQFP-144 CE P9.5 20MHz APP
60
55
50
45
40
dBµV
35
30
25
20
15
10
5
0
0
100
200
300
400
500
600
700
800
900
1000
Frequency/MHz
Figure 19
Test Report
PG-LQFP-144; Application; P9.5 conducted; 20 MHz
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Electromagnetic Emission Summary
XC2000 and XE166 Family Derivatives / Base Line
Application-typical conducted emission on I/O net at upper package edge; system clock is 80 MHz.
PG-LQFP-64 CE P10.14 80MHz APP
60
55
50
45
40
dBµV
35
30
25
20
15
10
5
0
0
100
200
300
400
500
600
700
800
900
1000
Frequency/MHz
Figure 20
PG-LQFP-64; Application; P10.14 conducted; 80 MHz
PG-LQFP-100 CE P1.4 80MHz APP
60
55
50
45
40
dBµV
35
30
25
20
15
10
5
0
0
100
200
300
400
500
600
700
800
900
1000
Frequency/MHz
Figure 21
PG-LQFP-100; Application; P1.4 conducted; 80 MHz
PG-LQFP-144 CE P9.5 80MHz APP
60
55
50
45
40
dBµV
35
30
25
20
15
10
5
0
0
100
200
300
400
500
600
700
800
900
1000
Frequency/MHz
Figure 22
Test Report
PG-LQFP-144; Application; P9.5 conducted; 80 MHz
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Electromagnetic Emission Summary
XC2000 and XE166 Family Derivatives / Base Line
Application-typical conducted emission on I/O net at left package edge; system clock is 20 MHz.
PG-LQFP-64 CE P6.1 20MHz APP
60
55
50
45
40
dBµV
35
30
25
20
15
10
5
0
0
100
200
300
400
500
600
700
800
900
1000
Frequency/MHz
Figure 23
PG-LQFP-64; Application; P6.1 conducted; 20 MHz
PG-LQFP-100 CE VAREF 20MHz APP
60
55
50
45
40
dBµV
35
30
25
20
15
10
5
0
0
100
200
300
400
500
600
700
800
900
1000
Frequency/MHz
Figure 24
PG-LQFP-100; Application; VAREF conducted; 20 MHz
PG-LQFP-144 CE VAREF 20MHz APP
60
55
50
45
40
dBµV
35
30
25
20
15
10
5
0
0
100
200
300
400
500
600
700
800
900
1000
Frequency/MHz
Figure 25
Test Report
PG-LQFP-144; Application; VAREF conducted; 20 MHz
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Electromagnetic Emission Summary
XC2000 and XE166 Family Derivatives / Base Line
Application-typical conducted emission on I/O net at left package edge; system clock is 80 MHz.
PG-LQFP-64 CE P6.1 80MHz APP
60
55
50
45
40
dBµV
35
30
25
20
15
10
5
0
0
100
200
300
400
500
600
700
800
900
1000
Frequency/MHz
Figure 26
PG-LQFP-64; Application; P6.1 conducted; 80 MHz
PG-LQFP-100 CE VAREF 80MHz APP
60
55
50
45
40
dBµV
35
30
25
20
15
10
5
0
0
100
200
300
400
500
600
700
800
900
1000
Frequency/MHz
Figure 27
PG-LQFP-100; Application; VAREF conducted; 80 MHz
PG-LQFP-144 CE VAREF 80MHz APP
60
55
50
45
40
dBµV
35
30
25
20
15
10
5
0
0
100
200
300
400
500
600
700
800
900
1000
Frequency/MHz
Figure 28
Test Report
PG-LQFP-144; Application; VAREF conducted; 80 MHz
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Electromagnetic Emission Summary
XC2000 and XE166 Family Derivatives / Base Line
Application-typical radiated emission; system clock is 20 MHz.
PG-LQFP-64 RE 20MHz APP
60
55
50
45
40
dBµV
35
30
25
20
15
10
5
0
0
100
200
300
400
500
600
700
800
900
1000
Frequency/MHz
Figure 29
PG-LQFP-64; Application; radiated; 20 MHz
PG-LQFP-100 RE 20MHz APP
60
55
50
45
40
dBµV
35
30
25
20
15
10
5
0
0
100
200
300
400
500
600
700
800
900
1000
Frequency/MHz
Figure 30
PG-LQFP-100; Application; radiated; 20 MHz
PG-LQFP-144 RE 20MHz APP
60
55
50
45
40
dBµV
35
30
25
20
15
10
5
0
0
100
200
300
400
500
600
700
800
900
1000
Frequency/MHz
Figure 31
Test Report
PG-LQFP-144; Application; radiated; 20 MHz
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Electromagnetic Emission Summary
XC2000 and XE166 Family Derivatives / Base Line
Application-typical radiated emission; system clock is 80 MHz.
PG-LQFP-64 RE 80MHz APP
60
55
50
45
40
dBµV
35
30
25
20
15
10
5
0
0
100
200
300
400
500
600
700
800
900
1000
Frequency/MHz
Figure 32
PG-LQFP-64; Application; radiated; 80 MHz
PG-LQFP-100 RE 80MHz APP
60
55
50
45
40
dBµV
35
30
25
20
15
10
5
0
0
100
200
300
400
500
600
700
800
900
1000
Frequency/MHz
Figure 33
PG-LQFP-100; Application; radiated; 80 MHz
PG-LQFP-144 RE 80MHz APP
60
55
50
45
40
dBµV
35
30
25
20
15
10
5
0
0
100
200
300
400
500
600
700
800
900
1000
Frequency/MHz
Figure 34
Test Report
PG-LQFP-144; Application; radiated; 80 MHz
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Electromagnetic Emission Summary
XC2000 and XE166 Family Derivatives / Base Line
6
Worst-Case Emission Tests
The microcontroller is running in “worst-case” mode. This means that in addition to the “application-specific”
settings, CLKOUT function is activated on port pin P2.8. The toggle rate on CLKOUT is equal to the system
clock (20MHz or 80MHz). The CLKOUT pin is set to the strongest driver setting “extra-strong”.
If CLKOUT is used to drive slower clocks, its P2.8 driver should be configured to weaker settings which
significantly reduce the electromagnetic emission; figures 35 and 36 show the emission reduction potential by
pad driver scaling for the two cases VDDP=5.0V and VDDP=3.3V.
dBµV
COMPARISON: XC2267/87, Conducted Emission Measurement at VDDP0
fsys=var., fosc=16MHz, VDDP0=5.0V, Cload=10pF
EXTCLK (P2.8) toggles at var. Frequency / Driver set to var.
70
65
60
55
50
45
40
35
30
25
20
15
10
5
0
EXTRA-STRONG 66MHz
STRONG-SHARP 40MHz
STRONG-MEDIUM 20MHz
STRONG-SOFT 20MHz
MEDIUM 2MHz
WEAK 500kHz
0
100
200
300
400
500
600
700
800
900
1000
Frequency/MHz
Figure 35
Emission reduction by pad driver settings for VDDP = 5.0V
dBµV
COMPARISON: XC2267/87, Conducted Emission Measurement at VDDP0
fsys=var., fosc=16MHz, VDDP0=3.3V, Cload=10pF
EXTCLK (P2.8) toggles at var. Frequency / Driver set to var.
70
65
60
55
50
45
40
35
30
25
20
15
10
5
0
EXTRA-STRONG 66MHz
STRONG-SHARP 40MHz
STRONG-MEDIUM 20MHz
STRONG-SOFT 10MHz
MEDIUM 2MHz
WEAK 500kHz
0
100
200
300
400
500
600
700
800
900
1000
Frequency/MHz
Figure 36
Test Report
Emission reduction by pad driver settings for VDDP = 3.3V
21
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Electromagnetic Emission Summary
XC2000 and XE166 Family Derivatives / Base Line
The weakest possible driver setting for a port pin depends on:
•
VDDP voltage
•
External capacitive load
•
Data rate
•
Edge-to-period ratio of the data signal
•
Ambient temperature
Figure 37 explains how to use the decision graphs provided in the “Scalable Pads Application Note” [1]. The title
of each diagram indicates the conditions (edge/voltage/temperature) for the shown values:
Edge is either “T/4” (meaning the rise time and the fall time take each 1/4 of the data rate period) or “T/6”
(meaning the rise time and the fall time take each 1/6 of the data rate period).
Voltage indicates the I/O pad supply voltage VDDP and is either 3.3 V or 5.0 V.
Temperature indicates the ambient temperature and ranges from -40°C up to +125°C.
The maximal clock/data rate to meet good signal integrity is given in [MHz] for capacitive loads of 10, 15, 22, 33,
47 pF and driver selections of weak, medium, strong soft/medium/sharp/extra-strong. In Fig. 35, the resulting
maximum data rates for the strong-medium driver are marked with red circles:
If the strong-medium driver is loaded with 10 pF (which means actually 13 pF including the oscilloscope probe
load), it is able to drive a clean 37 MHz signal (under the above mentioned edge/voltage/temperature
conditions).
An 18 pF load (15+3pF) can be driven at 31 MHz; a 25 pF load (22+3 pF) can be driven at 30 MHz;
a 36 pF load (33+3pF) can be driven at 28 MHz; a 50 pF load (47+3 pF) can be driven at 26 MHz.
Figure 37
Test Report
Explanation of pad driver selection diagram
22
V1.0, 2009-04
AP16167
Electromagnetic Emission Summary
XC2000 and XE166 Family Derivatives / Base Line
Figures 38 to 41 show decision graphs for some variations of these parameters. It is assumed that rising edge
and falling edge occupy ¼ of the signal period. For a full description and suggestions please refer to [1].
Frequency Limits, Edge=T/4 (5V) -40°C
160
150
140
130
120
Frequency [MHz]
110
100
90
80
70
60
50
40
30
20
10
0
XST
47
SSH
33
SME
Driver
SSO
22
MED
C load [pF]
15
WEA
Figure 38
150-160
140-150
130-140
120-130
110-120
100-110
90-100
80-90
70-80
60-70
50-60
40-50
30-40
20-30
10-20
0-10
10
Pad driver selection for VDDP = 5.0 V at -40°C
Frequency Limits, Edge=T/4 (5V) 125°C
140
130
120
110
130-140
120-130
110-120
100-110
90-100
80-90
70-80
60-70
50-60
40-50
30-40
20-30
10-20
0-10
Frequency [MHz]
100
90
80
70
60
50
40
30
20
10
0
XST
47
SSH
33
SME
Driver
SSO
22
MED
WEA
Figure 39
Test Report
C load [pF]
15
10
Pad driver selection for VDDP = 5.0 V at +125°C
23
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AP16167
Electromagnetic Emission Summary
XC2000 and XE166 Family Derivatives / Base Line
Frequency Limits, Edge=T/4 (3,3V) -40°C
130
120
110
100
Frequency [MHz]
90
120-130
110-120
100-110
90-100
80-90
70-80
60-70
50-60
40-50
30-40
20-30
10-20
0-10
80
70
60
50
40
30
20
10
0
XST
47
SSH
33
SME
Driver
SSO
22
MED
WEA
Figure 40
C load [pF]
15
10
Pad driver selection for VDDP = 3.3 V at -40°C
Frequency Limits, Edge=T/4 (3,3V) 125°C
70
65
60
55
65-70
60-65
55-60
50-55
45-50
40-45
35-40
30-35
25-30
20-25
15-20
10-15
5-10
0-5
Frequency [MHz]
50
45
40
35
30
25
20
15
10
5
0
XST
47
SSH
33
SME
Driver
SSO
22
MED
WEA
Figure 41
Test Report
C load [pF]
15
10
Pad driver selection for VDDP = 3.3 V at +125°C
24
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Electromagnetic Emission Summary
XC2000 and XE166 Family Derivatives / Base Line
General remarks:
The microcontroller is running in “worst-case” mode. The general hardware settings are described in chapter 4.
The I/O supply voltage VDDP is set to 5.0V.
Any emission peaks in the 900 MHz range rising from lower noise floor result from GSM transmitters and are
not related to microcontroller operation.
Summary of emission behaviour in worst-case operating mode:
1) I/O noise is efficiently coupled to VDDI, especially in the smallest PG-LQFP-64 package. VDDI emission
from CLKOUT is less in PG-LQFP-100 and PG-LQFP-144, where QFP144 shows the lowest CLKOUT
coupling.
2) I/O noise is massively seen as VDDP emission. Here, the smallest package QFP64 shows the best
damping towards high frequency > 600 MHz. VDDP emission from CLKOUT is less and comparable in
PG-LQFP-100 and PG-LQFP-144 with significant high-frequency peaks above 600 MHz.
3) I/O pin emission is highest between 500 and 700 MHz. Reason is that crosstalk from VDDP to the port
pins becomes more efficient at higher frequency. Above 700 MHz, the natural damping occurs. Please
note that all I/O pins where emission is measured are inactive (i.e. not switching) pads which are set to
state “output low”. From the emission shape, special care on PCB layout might be necessary to prevent
I/O noise from being coupled to any antenna structures on the PCB. Advisable PCB layout rules are:
b. Keep signal traces short
c.
Route signal traces as micro-strip or stripline (ground shielding)
d. Avoid signal trace vias through power or ground planes
e. Use lowest permissable data rates
f.
Use weakest permissable pad driver settings
For further recommendations please refer to Infineon’s application notes listed in chapter 7.
4) Summarized, the activation of any high-speed clock or data driver with strongest settings rise real layout
challenges for low-emission PCB layout. Thus high-speed signals should be avoided. If this is not
possible, they should be limited by clock rate and driver strength. Hints for the expected emission
reduction have been provided above. In case of strong high-speed signals, the smallest package
PG-LQFP-64 shows lowest emission on I/O signals; minor differences are visible between PG-LQFP100 and PG-LQFP-144. The bigger packages show significant high-frequency emission on I/O nets.
5) Radiated emission exceeds the BISS limits. The level can be significantly decreased when operating
I/Os at lower speed and select weaker driver strengths, as discussed above. All packages show similar
emission, where the PG-LQFP-64 stays ca. 6dB below the bigger ones.
Test Report
25
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AP16167
Electromagnetic Emission Summary
XC2000 and XE166 Family Derivatives / Base Line
Worst-case conducted emission on core supply net VDDI; system clock is 20 MHz.
PG-LQFP-64 CE VDDI 20MHz WC
60
55
50
45
40
dBµV
35
30
25
20
15
10
5
0
0
100
200
300
400
500
600
700
800
900
1000
Frequency/MHz
Figure 42
PG-LQFP-64; Worst-case; VDDI conducted; 20 MHz
PG-LQFP-100 CE VDDI 20MHz WC
60
55
50
45
40
dBµV
35
30
25
20
15
10
5
0
0
100
200
300
400
500
600
700
800
900
1000
Frequency/MHz
Figure 43
PG-LQFP-100; Worst-case; VDDI conducted; 20 MHz
PG-LQFP-144 CE VDDI 20MHz WC
60
55
50
45
40
dBµV
35
30
25
20
15
10
5
0
0
100
200
300
400
500
600
700
800
900
1000
Frequency/MHz
Figure 44
Test Report
PG-LQFP-144; Worst-case; VDDI conducted; 20 MHz
26
V1.0, 2009-04
AP16167
Electromagnetic Emission Summary
XC2000 and XE166 Family Derivatives / Base Line
Worst-case conducted emission on core supply net VDDI; system clock is 80 MHz.
PG-LQFP-64 CE VDDI 80MHz WC
60
55
50
45
40
dBµV
35
30
25
20
15
10
5
0
0
100
200
300
400
500
600
700
800
900
1000
Frequency/MHz
Figure 45
PG-LQFP-64; Worst-case; VDDI conducted; 80 MHz
PG-LQFP-100 CE VDDI 80MHz WC
60
55
50
45
40
dBµV
35
30
25
20
15
10
5
0
0
100
200
300
400
500
600
700
800
900
1000
Frequency/MHz
Figure 46
PG-LQFP-100; Worst-case; VDDI conducted; 80 MHz
PG-LQFP-QFP100 CE VDDI 80MHz WC
60
55
50
45
40
dBµV
35
30
25
20
15
10
5
0
0
100
200
300
400
500
600
700
800
900
1000
Frequency/MHz
Figure 47
Test Report
PG-LQFP-144; Worst-case; VDDI conducted; 80 MHz
27
V1.0, 2009-04
AP16167
Electromagnetic Emission Summary
XC2000 and XE166 Family Derivatives / Base Line
Worst-case conducted emission on I/O supply net VDDP; system clock is 20 MHz.
PG-LQFP-64 CE VDDP 20MHz WC
60
55
50
45
40
dBµV
35
30
25
20
15
10
5
0
0
100
200
300
400
500
600
700
800
900
1000
Frequency/MHz
Figure 48
PG-LQFP-64; Worst-case; VDDP conducted; 20 MHz
PG-LQFP-100 CE VDDP 20MHz WC
60
55
50
45
40
dBµV
35
30
25
20
15
10
5
0
0
100
200
300
400
500
600
700
800
900
1000
Frequency/MHz
Figure 49
PG-LQFP-100; Worst-case; VDDP conducted; 20 MHz
PG-LQFP-144 CE VDDP 20MHz WC
60
55
50
45
40
dBµV
35
30
25
20
15
10
5
0
0
100
200
300
400
500
600
700
800
900
1000
Frequency/MHz
Figure 50
Test Report
PG-LQFP-144; Worst-case; VDDP conducted; 20 MHz
28
V1.0, 2009-04
AP16167
Electromagnetic Emission Summary
XC2000 and XE166 Family Derivatives / Base Line
Worst-case conducted emission on I/O supply net VDDP; system clock is 80 MHz.
PG-LQFP-64 CE VDDP 80MHz WC
60
55
50
45
40
dBµV
35
30
25
20
15
10
5
0
0
100
200
300
400
500
600
700
800
900
1000
Frequency/MHz
Figure 51
PG-LQFP-64; Worst-case; VDDP conducted; 80 MHz
PG-LQFP-100 CE VDDP 80MHz WC
60
55
50
45
40
dBµV
35
30
25
20
15
10
5
0
0
100
200
300
400
500
600
700
800
900
1000
Frequency/MHz
Figure 52
PG-LQFP-100; Worst-case; VDDP conducted; 80 MHz
PG-LQFP-144 CE VDDP 80MHz WC
60
55
50
45
40
dBµV
35
30
25
20
15
10
5
0
0
100
200
300
400
500
600
700
800
900
1000
Frequency/MHz
Figure 53
Test Report
PG-LQFP-144; Worst-case; VDDP conducted; 80 MHz
29
V1.0, 2009-04
AP16167
Electromagnetic Emission Summary
XC2000 and XE166 Family Derivatives / Base Line
Worst-case conducted emission on I/O net at upper package edge; system clock is 20 MHz.
PG-LQFP-64 CE P10.14 20MHz WC
60
55
50
45
40
dBµV
35
30
25
20
15
10
5
0
0
100
200
300
400
500
600
700
800
900
1000
Frequency/MHz
Figure 54
PG-LQFP-64; Worst-case; P10.14 conducted; 20 MHz
PG-LQFP-100 CE P1.4 20MHz WC
60
55
50
45
40
dBµV
35
30
25
20
15
10
5
0
0
100
200
300
400
500
600
700
800
900
1000
Frequency/MHz
Figure 55
PG-LQFP-100; Worst-case; P1.4 conducted; 20 MHz
PG-LQFP-144 CE P9.5 20MHz WC
60
55
50
45
40
dBµV
35
30
25
20
15
10
5
0
0
100
200
300
400
500
600
700
800
900
1000
Frequency/MHz
Figure 56
Test Report
PG-LQFP-144; Worst-case; P9.5 conducted; 20 MHz
30
V1.0, 2009-04
AP16167
Electromagnetic Emission Summary
XC2000 and XE166 Family Derivatives / Base Line
Worst-case conducted emission on I/O net at upper package edge; system clock is 80 MHz.
PG-LQFP-64 CE P10.14 80MHz WC
60
55
50
45
40
dBµV
35
30
25
20
15
10
5
0
0
100
200
300
400
500
600
700
800
900
1000
Frequency/MHz
Figure 57
PG-LQFP-64; Worst-case; P10.14 conducted; 80 MHz
PG-LQFP-100 CE P1.4 80MHz WC
60
55
50
45
40
dBµV
35
30
25
20
15
10
5
0
0
100
200
300
400
500
600
700
800
900
1000
Frequency/MHz
Figure 58
PG-LQFP-100; Worst-case; P1.4 conducted; 80 MHz
PG-LQFP-144 CE P9.5 80MHz WC
60
55
50
45
40
dBµV
35
30
25
20
15
10
5
0
0
100
200
300
400
500
600
700
800
900
1000
Frequency/MHz
Figure 59
Test Report
PG-LQFP-144; Worst-case; P9.5 conducted; 80 MHz
31
V1.0, 2009-04
AP16167
Electromagnetic Emission Summary
XC2000 and XE166 Family Derivatives / Base Line
Worst-case conducted emission on I/O net at left package edge; system clock is 20 MHz.
PG-LQFP-64 CE P6.1 20MHz WC
60
55
50
45
40
dBµV
35
30
25
20
15
10
5
0
0
100
200
300
400
500
600
700
800
900
1000
Frequency/MHz
Figure 60
PG-LQFP-64; Worst-case; P6.1 conducted; 20 MHz
PG-LQFP-100 CE VAREF 20MHz WC
60
55
50
45
40
dBµV
35
30
25
20
15
10
5
0
0
100
200
300
400
500
600
700
800
900
1000
Frequency/MHz
Figure 61
PG-LQFP-100; Worst-case; VAREF conducted; 20 MHz
PG-LQFP-144 CE VAREF 20MHz WC
60
55
50
45
40
dBµV
35
30
25
20
15
10
5
0
0
100
200
300
400
500
600
700
800
900
1000
Frequency/MHz
Figure 62
Test Report
PG-LQFP-144; Worst-case; VAREF conducted; 20 MHz
32
V1.0, 2009-04
AP16167
Electromagnetic Emission Summary
XC2000 and XE166 Family Derivatives / Base Line
Worst-case conducted emission on I/O net at left package edge; system clock is 80 MHz.
PG-LQFP-64 CE P6.1 80MHz WC
60
55
50
45
40
dBµV
35
30
25
20
15
10
5
0
0
100
200
300
400
500
600
700
800
900
1000
Frequency/MHz
Figure 63
PG-LQFP-64; Worst-case; P6.1 conducted; 80 MHz
PG-LQFP-100 CE VAREF 80MHz WC
60
55
50
45
40
dBµV
35
30
25
20
15
10
5
0
0
100
200
300
400
500
600
700
800
900
1000
Frequency/MHz
Figure 64
PG-LQFP-100; Worst-case; VAREF conducted; 80 MHz
PG-LQFP-144 CE VAREF 80MHz WC
60
55
50
45
40
dBµV
35
30
25
20
15
10
5
0
0
100
200
300
400
500
600
700
800
900
1000
Frequency/MHz
Figure 65
Test Report
PG-LQFP-144; Worst-case; VAREF conducted; 80 MHz
33
V1.0, 2009-04
AP16167
Electromagnetic Emission Summary
XC2000 and XE166 Family Derivatives / Base Line
Worst-case radiated emission; system clock is 20 MHz.
PG-LQFP-64 RE 20MHz WC
60
55
50
45
40
dBµV
35
30
25
20
15
10
5
0
0
100
200
300
400
500
600
700
800
900
1000
Frequency/MHz
Figure 66
PG-LQFP-64; Worst-case; radiated; 20 MHz
PG-LQFP-100 RE 20MHz WC
60
55
50
45
40
dBµV
35
30
25
20
15
10
5
0
0
100
200
300
400
500
600
700
800
900
1000
Frequency/MHz
Figure 67
PG-LQFP-100; Worst-case; radiated; 20 MHz
PG-LQFP-144 RE 20MHz WC
60
55
50
45
40
dBµV
35
30
25
20
15
10
5
0
0
100
200
300
400
500
600
700
800
900
1000
Frequency/MHz
Figure 68
Test Report
PG-LQFP-144; Worst-case; radiated; 20 MHz
34
V1.0, 2009-04
AP16167
Electromagnetic Emission Summary
XC2000 and XE166 Family Derivatives / Base Line
Worst-case radiated emission; system clock is 80 MHz.
PG-LQFP-64 RE 80MHz WC
60
55
50
45
40
dBµV
35
30
25
20
15
10
5
0
0
100
200
300
400
500
600
700
800
900
1000
Frequency/MHz
Figure 69
PG-LQFP-64; Worst-case; radiated; 80 MHz
PG-LQFP-100 RE 80MHz WC
60
55
50
45
40
dBµV
35
30
25
20
15
10
5
0
0
100
200
300
400
500
600
700
800
900
1000
Frequency/MHz
Figure 70
PG-LQFP-100; Worst-case; radiated; 80 MHz
PG-LQFP-144 RE 80MHz WC
60
55
50
45
40
dBµV
35
30
25
20
15
10
5
0
0
100
200
300
400
500
600
700
800
900
1000
Frequency/MHz
Figure 71
Test Report
PG-LQFP-144; Worst-case; radiated; 80 MHz
35
V1.0, 2009-04
AP16167
Electromagnetic Emission Summary
XC2000 and XE166 Family Derivatives / Base Line
7
References
These documents can be downloaded from the Infineon microcontroller internet pages:
http://www.infineon.com/cms/en/product/channel.html?channel=db3a30431c69a49d011c8a7c069203dc
[1] Scalable pads application notes Æ ap1612011_scalable-pads-xc2000-xe166.pdf
[2] XC2000 and XE166 Family EMC guidelines for PCB design Æ AP1611621_XC2000_XE166_PCB.pdf
http://www.infineon.com/cms/en/product/channel.html?channel=ff80808112ab681d0112ab6b2dfc0756
[3] General EMC guidelines for PCB design Æ ap2402633_EMC_Guidelines.pdf
These documents are available on request:
•
Generic IC EMC Test Specification (“BISS paper”), open copyright 2004 by Robert Bosch GmbH,
Infineon Technologies AG, Continental AG (former Siemens-VDO)
•
Electromagnetic Emission Test Report for XC2000 and XE166 Family Base Line Derivatives in
PG-LQFP-64 Package, Sept. 2008
•
Electromagnetic Emission Test Report for XC2000 and XE166 Family Base Line Derivatives in
PG-LQFP-100 Package, July 2008
•
Electromagnetic Emission Test Report for XC2000 and XE166 Family Base Line Derivatives in
PG-LQFP-144 Package, July 2008
Test Report
36
V1.0, 2009-04
AP16167
Electromagnetic Emission Summary
XC2000 and XE166 Family Derivatives / Base Line
8
Executive Summary
1) Conducted and radiated emissions of all XC2000 and XE166 Family Base Line Derivatives stay below
the BISS limits for application-typical operation up to 80 MHz and thus should not cause any severe
problems for low-emission PCB design.
2) PG-LQFP-64 derivatives show higher emission than PG-LQFP-100 and PG-LQFP-144 due to missing
VSS e-pad. Thus more care on power routing and noise decoupling should be taken for PCBs using
PG-LQFP-64 devices. For PG-LQFP-100 and PG-LQFP-144 it is strongly recommended to solder the
VSS e-pad.
3) Since all microcontrollers use internal volage regulators, the VDDI pins should only be connected to
local decoupling capacitors. Thus no effective antenna structure to radiate emission from VDDI should
be provided on the PCB, and the VDDI emission should not be system-relevant.
4) Core noise coupling from VDDI to VDDP is efficiently suppressed in PG-LQFP-100 and PG-LQFP-144
devices, but some coupling happens on the PG-LQFP-64 package which is again due to the missing
VSS e-pad which offers a low-impedance common reference point for the VDDI and VDDP noise.
5) I/O emission (i.e. noise propagation through inactive pads) is – in contrast to supply emission – visible
up to 1 GHz. Reason is that there is no available on-chip space to design decoupling capacitors for the
VDDP system. Also I/O pins can neither be decoupled on chip nor on PCB. Special care on PCB layout
is advisable to prevent I/O noise from being coupled to any antenna structures on the PCB:
a. Keep signal traces short
b. Route signal traces as micro-strip or stripline (ground shielding)
c.
Avoid signal trace vias through power or ground planes
d. Use lowest permissable data rates
e. Use weakest permissable pad driver settings
For further recommendations please refer to Infineon’s application notes listed in chapter 7.
6) Conducted and radiated emission exceeds the BISS limits if the strongest pad drivers are selected for
high-speed signals. The level can be significantly decreased when operating I/Os at lower speed and
select weaker driver strengths, as discussed above. All packages show similar emission, where the
smallest PG-LQFP-64 stays ca. 6 dB below the bigger ones.
7) I/O noise is visible on VDDP, but also coupled to VDDI, especially in the smallest PG-LQFP-64
package. VDDI emission from CLKOUT is less in PG-LQFP-100 and PG-LQFP-144, where the
PG-LQFP-144 shows the lowest CLKOUT coupling. I/O pin emission is highest between 500 MHz and
700 MHz. Reason is that crosstalk from VDDP to the port pins becomes more efficient at higher
frequency. Above 700 MHz, the natural damping occurs.
8) The part of conducted and radiated emission which is caused by switching I/O noise will decrease when
the VDDP voltage is lowered from 5.0 V to 3.3 V. In this case emission peaks may be reduced by ca.
6 dB.
9) The activation of any high-speed clock or data driver with strongest settings rise real layout challenges
for low-emission PCB layout. Thus high-speed signals should be avoided. If this is not possible, they
should be limited by clock rate and driver strength. In case of strong high-speed signals, the smallest
package PG-LQFP-64 shows lowest emission on I/O signals; minor differences are visible between
PG-LQFP-100 and PG-LQFP-144.
Test Report
37
V1.0, 2009-04
w w w . i n f i n e o n . c o m
Published by Infineon Technologies AG
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