AN4474, EMC and Transient Performance for the Dual 24 V High-Side Switch Family - Application Note

Freescale Semiconductor
Application Note
Document Number: AN4474
Rev. 2.0, 9/2012
EMC and Transient Performance for the
Dual 24 V High-Side Switch Family
1
Introduction
This application note describes the EMC and fast transient
pulse capability of the MC06XS4200, MC10XS4200, and
MC20XS4200 devices. These intelligent high side switches
are designed to be used in 24 V systems such as trucks,
busses, and special engines. They can be used in some
industrial and 12 V applications as well. The low RDS(ON)
channels can control incandescent lamps, LEDs, solenoids,
or DC motors. Control, device configuration, and diagnostics
are performed through a 16-bit SPI interface, allowing easy
integration into existing applications. For a complete feature
description, refer to the individual data sheets.
Contents
1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
2 EMC Board Setup . . . . . . . . . . . . . . . . . . . . . . . 2
3 Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . 4
3.1 Conducted Emission Measurements . . . . 4
3.2 Conducted Immunity Measurements . . . . 5
3.3 Fast Transient Pulse Measurements . . . . 6
3.4 Decoupling Capacitors Role. . . . . . . . . . . 7
4 References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
5 Revision History . . . . . . . . . . . . . . . . . . . . . . . . 9
© Freescale Semiconductor, Inc., 2012. All rights reserved.
EMC Board Setup
2
EMC Board Setup
KIT06XS4200EVBE, KIT10XS4200EVBE, and KIT20XS4200EVBE are composed of four layers. They are used for
testing with the following resistor and capacitor values (X7R 100 V):
•
•
•
On VPWR: 100 nF and 1.0 μF are placed close to the 06XS4200 device
For each output: 22 nF is located at the output connector
Low pass filter on the CSNS output pin: 10 kΩ + 22 nF
Figure 1. 24 V High Side Switch Evaluation Board
2
EMC and Transient Performance for the Dual 24 V High-Side Switch Family, Rev. 2.0
Freescale Semiconductor
EMC Board Setup
VDD
VPWR
VDD
VPWR
06XS4200
VDD
VDD
100 k
10 k
VPWR
100 nF
100 nF
10 k
VDD
I/O
CLOCK
I/O
FSB
IN1
MCU
SCLK
CSB
I/O
SO
SI
75 k
75 k
A/D
A/D
1.0 k
22 nF
22 nF
FSOB
SCLK
CSB
RSTB
SI
SO
CONF0
CONF1
SYNC
CSNS
1.0 µF
HS0
IN0
GND
to increase
device robustness
against fast
transient pulse
robustness
LOAD 0
HS1
M
22 nF
LOAD 1
GND
2.0 k
10 k
Figure 2. Application Schematic
EMC and Transient Performance for the Dual 24 V High-Side Switch Family, Rev. 2.0
Freescale Semiconductor
3
Measurements
3
3.1
Measurements
Conducted Emission Measurements
Conducted emission is the emission produced by the device on the battery cable. The bench test is described by
the CISPR25 standard. The Line Impedance Stabilization Network (LISN), also called the Artificial Network (AN), in
a given frequency range (150 kHz to 108 MHz), provides a specified load impedance for the measurement of
disturbance voltages, and isolates the equipment under test (EUT) from the supply in that frequency range. The EUT
must operate under typical loading and other conditions, just as it is in the vehicle, so that a maximum emission state
occurs. These operating conditions are clearly defined in the test plan to ensure that both supplier and customer are
performing identical tests.
For the testing described, the device was in Sleep, Standby, and Normal modes, and each output pins of the
06XS4200, was connected to 24 V 70 W lamp(s) or 24 V 160 mA LEDs. The ground return of the lamps was
connected to the chassis and the ground path of the EUT flowed into the LISN. The power supply voltage is 24 V
(double car battery). The SPI watchdog feature was disabled for this test.
The results of those measurements are represented in the following table:
Table 1. Conducted Emission Results
Load per
output
Mode
All outputs OFF
70 W lamp
Sleep
Class 5
All outputs OFF
70 W lamp
Standby
Class 5
Conducted Emissions
Outputs PWMing in same time @ 400 Hz
with 50% of duty-cycle
Outputs PWMing with 180° phasing @
400 Hz with 50% of duty-cycle
4
Class 4 with Medium Slew rate SPI setting
Class 5 with Fast Slew rate SPI setting
2x70 W lamps
160 mA LED
2x70 W lamps
CISPR25:2008 level
Normal
Class 5 with Medium Slew rate SPI setting
Class 5 with Fast Slew rate SPI setting
Class 5 with Medium Slew rate SPI setting
Class 5 with Fast Slew rate SPI setting
as presented in Figure 3
EMC and Transient Performance for the Dual 24 V High-Side Switch Family, Rev. 2.0
Freescale Semiconductor
Measurements
Figure 3. Normal Mode - Both Outputs PWMing @ 400 Hz with 50%of Duty Cycle
3.2
Conducted Immunity Measurements
Conducted immunity is the device susceptibility for RF injection applied directly on a device terminal. The bench test
is described by the 62132-4 specification (Direct Power Injection) from the International Electrotechnical
Commission. The following performance grades have been used to characterize the device performance:
Table 2. Performance Grades Description
Class A:
All functions of the IC perform as designed during and after exposure to a disturbance.
Class B:
All functions of the IC perform as designed during exposure, however, one or more of them may go beyond the
specified tolerance. All functions return automatically to within normal limits after exposure is removed. Memory
functions shall remain in class A.
Class C:
A function of the IC doesn’t perform as designed during exposure but returns automatically to normal operation
after exposure is removed.
Class D:
A function of the IC doesn’t perform as designed during exposure, and doesn’t return to normal operation until
exposure is removed and the IC is reset by simple operator action (e.g. put off supply...).
Class E:
One or more functions of an integrated circuit do not perform as designed during and after exposure and cannot
be returned to proper operation.
For the testing described, the device was in Sleep, Standby, and Normal modes, and each output terminal of the
06XS4200 was connected to 70 W lamp(s). The ground return of the bulb was connected to the chassis, and the
ground path of the EUT flowed into the LISN. The power supply voltage is 24 V (double car battery).
The results of these measurements are represented in the following table. Output states, analog current sensing,
and digital fault reporting are in accordance with the Class A for 25 dBm of power injection from 1.0 MHz to 1.0 GHz
on the VPWR pin.
EMC and Transient Performance for the Dual 24 V High-Side Switch Family, Rev. 2.0
Freescale Semiconductor
5
Measurements
Table 3. Conducted Immunity Results
Feature
Load
Mode
Class
70 W lamp
Sleep and Standby
A
2x70 W lamps
Normal
A
All outputs OFF
All outputs ON
Outputs PWMing in same time @ 400 Hz with 50% of duty cycle
3.3
Fast Transient Pulse Measurements
Transient pulse immunity is the device susceptibility for fast transient pulse applied directly on the VPWR and HS
pins. The transient pulses are described by the ISO7637-2 standard from the International Electrotechnical
Commission. The power supply voltage is 28 V.
For the testing on VPWR, the device was in Sleep state or Fail-safe mode with IGN = 5.0 V, and the output pins of
the 06XS4200 were connected respectively to a resistive load. The results of those measurements are represented
in Table 4.
Table 4. Fast Transient Pulse Results (disturbance on VPWR)
Schaffner pulses applied on VPWR
Sleep state
All outputs OFF
Pulse 1 (RI = 50 Ω, -600 V, 1000 occurrences)
Pass for HS0 loaded with a resistive load < 2.2 Ω
Pulse 2a (RI = 2.0 Ω, +50 V, 1000 occurrences)
Pass
Pulse 3a (RI = 50 Ω, -200 V, 8.0 min)
Pass
Pulse 3b (RI = 50 W, +200 V, 8.0 min)
Pass
Pulse 5b (RI = 1.0 W, +87 V clamped at +58 V, 10 occurrences)
Pass
In the case of an open load condition or high-ohmic load (> 2.2 Ω), the transient pulses are handled by the
application with a transient voltage suppressor between VPWR and GND, as presented in Decoupling Capacitors
Role.
For testing on one output, the device was in Sleep state mode and the fast negative pulse is applied on one unloaded
output. The second output is unloaded as well. Results of these measurements are described in the following table.
Table 5. Fast Transient Pulse Results (disturbance on HSx)
Sleep state mode
All outputs OFF
Schaffner pulses applied on the output (HSx)
Pulse 1 (RI = 50 Ω, -600 V, tRISE = 1.0 µsec, 100 occurrences)
6
Pass
EMC and Transient Performance for the Dual 24 V High-Side Switch Family, Rev. 2.0
Freescale Semiconductor
Measurements
3.4
Decoupling Capacitors Role
The following table summarizes the mission of each component.
Table 6. Component Role and Value
Signal
Location
Mission
Value
VPWR
Close to 06XS4200 device
Reduction of emission and immunity
100 nF (X7R 100 V)
1.0 µF (X7R 100 V)
VDD
Close to 06XS4200 device
Reduction of emission and immunity
100 nF (X7R 100 V)
HSx
Close to output connectors
Reduction of emission and fast transient
negative pulse sustaining
22 nF (X7R 100 V)
CSNS
Close to the MCU
Low pass filter to remove noise during immunity
test
10 kΩ + 22 nF (X7R 16 V)
To increase device robustness against fast transient pulse robustness:
VPWR
Close to ECU connector to
increase device robustness
against fast transient pulse
robustness
Sustain pulse #1 in case of high-ohmic load (or
without loads)
40 V zener diode and 1N5353
diode in series per battery line
EMC and Transient Performance for the Dual 24 V High-Side Switch Family, Rev. 2.0
Freescale Semiconductor
7
References
4
References
PART NUMBER
DOCUMENT TYPE
MC06XS4200
Data sheet
•
Dual 24 V High Side Switch (6.0 mΩ)
MC10XS4200
Data sheet
•
Dual 24 V High Side Switch (10 mΩ)
MC20XS4200
Data sheet
•
Dual 24 V High Side Switch (20 mΩ)
MC06XS4200
Evaluation Board User Guide •
Dual 24 V High Side Switch (6.0 mΩ)
MC10XS4200
Evaluation Board User Guide •
Dual 24 V High Side Switch (10 mΩ)
MC20XS4200
Evaluation Board User Guide •
Dual 24 V High Side Switch (20 mΩ)
White Paper
• CISPR Standard white paper
Specification
• IEC 62132-4 Specification (Direct Power Injection)
Standards Document
8
DESCRIPTION / URL
• ISO 7637-2 Standard
EMC and Transient Performance for the Dual 24 V High-Side Switch Family, Rev. 2.0
Freescale Semiconductor
Revision History
5
Revision History
REVISION
DATE
DESCRIPTION OF CHANGES
1.0
6/2012
• Initial Release
2.0
8/2012
• Wording clarifications
EMC and Transient Performance for the Dual 24 V High-Side Switch Family, Rev. 2.0
Freescale Semiconductor
9
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© 2012 Freescale Semiconductor, Inc.
Document Number: AN4474
Rev. 2.0
9/2012
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