AN4542, Repetitive Short-circuit Performances for Dual 24 V High-side Switch ...

Freescale Semiconductor
Application Note
AN4542
Rev. 2.0, 12/2014
Repetitive Short-circuit Performances for Dual 24 V High-side
Switch Family
1
Introduction
This application note describes the robustness of the
MC06XS4200, MC10XS4200, MC22XS4200, and
MC50XS4200 devices. These intelligent high-side
switches are designed to be used in 24 V systems,
such as trucks and busses. 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 (serial peripheral interface) interface,
allowing for easy integration into existing applications.
For a complete feature description, refer to the relevant
data sheets.
© Freescale Semiconductor, Inc., 2014. All rights reserved.

Contents
1 Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1
2 Short-circuit Protections Features . . . . . . . . . . . . . .2
2.1 Configurable Latched Overcurrent Protection . .2
2.2 Severe Short-circuit Protection . . . . . . . . . . . . . .3
3 Short-circuit Tests . . . . . . . . . . . . . . . . . . . . . . . . . . .3
3.1 Test Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4
3.2 Short-circuit Test Results. . . . . . . . . . . . . . . . . . .4
3.3 Overload Test Results . . . . . . . . . . . . . . . . . . . . .7
4 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8
5 Revision History . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9
Short-circuit Protections Features
2
Short-circuit Protections Features
These SMARTMOS devices include dual self-protected high-side switches with enhanced diagnostics.
In case of a short-circuit from the HSx pin to the ground, the corresponding high-side switch is
immediately turned off via two overload protection features:
• Configurable latched overcurrent protection
• Severe short-circuit protection
These protections are preferred over conventional current limitations, to minimize the thermal
overstress within the device in an overload condition. The elevation of junction temperature is drastically
reduced to a value which does not affect the device’s reliability.
Moreover, the availability of the load is guaranteed by the auto-retry feature. According to the SPI
configuration, the number of retries is limited to 16, or unlimited. The repetition period of auto-retry is
also selectable through the SPI from 17.7 ms to 150 ms (typ.).
The high-side switches can be paralleled to drive higher currents. Setting the PARALLEL bit (a bit in the
GCR register) is mandatory, to synchronize the turn-off of the outputs, in the event of a short-circuit. If
the outputs are not switched concurrently, the device will be damaged, as illustrated in Figure 1.
Parallel bit = 0
Parallel bit = 1
DAMAGED
PASS
Figure 1. Short-circuit Event with Paralleled MC06XS4200 HSx Pins
2.1
Configurable Latched Overcurrent Protection
The transient overcurrent profile is adjustable, to account for the variability of load and the energy
associated with the expected wire harness current capability. The device incorporates multiple
configurable overcurrent profiles, to address lighting and DC motor applications, as illustrated in
Figure 2.
Repetitive Short-Circuit Performances, Rev. 2.0
2
Freescale Semiconductor
Short-circuit Tests
DC Motor Load Profile:
Dynamic overcurrent window, activated
when the IOCLx threshold is crossed
Lamp load Profile:
Static Overcurrent protection profile
activated once per turn-on.
Load
Current
IOCH1
IOCH1
IOCH2
IOCH2
IOCM1
IOCM2
IOCL1
IOCL1
IOCL2
IOCL2
IOCL3
Load curre
IOCL3
Time
T
t OCM2_L
t OCM2_M
t OCM1_L
t OCM1_M
t OCH2
t OCH2
t OCH1
t OCH1
Figure 2. Configurable Overcurrent Profile
The transient overcurrent profile protects the application, if the load is also driven in the PWM
(pulse-width modulation) mode.
2.2
Severe Short-circuit Protection
In addition to latched overcurrent protection, a severe short-circuit detection is available during off-to-on
switching, to immediately turn off the output.
3
Short-circuit Tests
To accelerate the silicon fatigue, the dual 24 V high-side switches are force to switch “on” and “off,”
cyclically. The ambient temperature was fixed at 85 °C. This is the worst case for this type of smart
power technology. At least five engineering samples were used per test.
Repetitive Short-Circuit Performances, Rev. 2.0
Freescale Semiconductor
3
Short-circuit Tests
Figure 3. Short-circuit Test Setup
3.1
Test Setup
Figure 3 presents the test setup used. Depending on the test that was performed, the test escape
condition was:
• A severe part damage for the “test to fail”
• A defined number of cycles for the “test to pass”
3.2
Short-circuit Test Results
3.2.1
MC06XS4200, MX10XS4200 (PQFN)
Test Description
High-side
Ambient DC Voltage PWM
Number of
Lsupply Rsupply Lshort Rshort Type of Test
Operation temperature source
freq.
Cycles
Short-circuit at the beginning
of the load line and occurred
in off-state of high-side
switch (cold short)
5.0 µH 5.0 m <1.0 µH 12 m test to pass
1.0 k
Short-circuit at the beginning Single switch
of the load line and occurred with default
Lighting
in on-state of high-side
Profile
switch (hot short)
5.0 µH 5.0 m 1.0 µH 15 m test to pass
1.0 k
85 °C
Short-circuit at the end of the
load line and occurred in
off-state of high-side switch
(cold short)
Short-circuit at the end of the Paralleled
load line and occurred in
switches
off-state of high-side switch with default
(cold short)
Lighting
Profile
32 V
2.0 Hz
3.7 µH
20 m
24 µH 166 m test to fail
Figure 4
Figure 5
3.7 µH
20 m
24 µH 166 m test to pass
500 k
Repetitive Short-Circuit Performances, Rev. 2.0
4
Freescale Semiconductor
Short-circuit Tests
For each “test to fail”, the cumulative failures over the number of cycles are presented in Figure 4 and
Figure 5. Gumbel’s predictive law, with 95% confidence level, is used to define the number of cycles to
failure, down to 10 PPM (parts per million) (1e-5).
Figure 4. Predictable MC10XS4200 Failures for a Short-circuit at the End of the Load Line
Figure 5. Predictable MC06XS4200 Failures for a Short-circuit at the End of the Load Line
Repetitive Short-Circuit Performances, Rev. 2.0
Freescale Semiconductor
5
Short-circuit Tests
3.2.2
MC22XS4200, MC50XS4200 (eSOIC)
Test Description
High-side
Ambient DC Voltage PWM
Number of
Lsupply Rsupply Lshort Rshort Type of Test
Operation temperature source
freq.
Cycles
Short-circuit at the beginning Single switch
of the load line and occurred with default
Lighting
in off-state of high side
Profile
switch (cold short)
85 °C
32 V
2.0 Hz 3.7 µH
20 m
24 µH 166 m test to fail
Figure 6
Figure 7
For each "test to fail", the cumulative failures over the number of cycles are presented in Figure 6 and
Figure 7. LogNormal's predictive law, with 95% confidence level, is used to define the number of cycles
to failure, down to 100 and 1000 PPM (parts per million) (1e-5).
Figure 6. Predictable MC22XS4200 Failures for a Short-circuit at the End of the Load Line
Repetitive Short-Circuit Performances, Rev. 2.0
6
Freescale Semiconductor
Short-circuit Tests
Figure 7. Predictable MC50XS4200 Failures for a Short-circuit at the End of the Load Line
3.3
Overload Test Results
Test Description
High Side
Ambient
Operation temperature
Overload 80% of OCHI
during toch1
(88 A during 8.6 ms for the
MC06XS4200 device)
Single
switch with
default
Lighting
Profile
Stalled Wiper DC Motor
with freewheeling diode
(20 A during 350 ms for
the MC06XS4200 device)
Single
switch with
default DC
motor
Profile
85 °C
DC
Voltage
Source
PWM
Lsupply Rsupply Lshort
freq
Rshort
Type of
Test
Number
of
Cycles
2.0 Hz
5.0 µH
5.0 m
20 µH
350 m
test to
pass
1.0 k
0.5 Hz
5.0 µH
5.0 m
20 µH
stall DC
motor
test to
pass
1.0 k
32 V
Repetitive Short-Circuit Performances, Rev. 2.0
Freescale Semiconductor
7
References
4
References
Document Number
Type
MC06XS4200
Data Sheet
Dual 24 V High Side Switch (6.0 mOhm) Data Sheet
MC10XS4200
Data Sheet
Dual 24 V High Side Switch (6.0 mOhm) Data Sheet
MC22XS4200
Data Sheet
Dual 24 V High Side Switch (22 mOhm) Data Sheet
MC50XS4200
Data Sheet
Dual 24 V High Side Switch (50 mOhm) Data Sheet
AN4516
Application Note
IBIS Model File for Dual 24 V High Side Switch Family
AN4473
Application Note
Compact Thermal Model for Dual 24 V High Side Switch Family
AN4474
Application Note
EMC and Fast Transient Pulses Performances for Dual 24 V High Side Switch Family
Freescale Website
Freescale Analog Webpage
Freescale Automotive Applications
Webpage
Description/URL
freescale.com
freescale.com/analog
freescale.com/automotive
Repetitive Short-Circuit Performances, Rev. 2.0
8
Freescale Semiconductor
Revision History
5
Revision History
Revision
Date
Description of Changes
1.0
10/2012
Initial release
2.0
12/2014
Added short-circuit results for MC22XS4200 and MC50XS4200
Updated document form and style
Repetitive Short-Circuit Performances, Rev. 2.0
Freescale Semiconductor
9
How to Reach Us:
Information in this document is provided solely to enable system and software implementers to use Freescale products.
Home Page:
freescale.com
There are no express or implied copyright licenses granted hereunder to design or fabricate any integrated circuits based
Web Support:
freescale.com/support
Freescale reserves the right to make changes without further notice to any products herein. Freescale makes no
on the information in this document.
warranty, representation, or guarantee regarding the suitability of its products for any particular purpose, nor does
Freescale assume any liability arising out of the application or use of any product or circuit, and specifically disclaims any
and all liability, including without limitation consequential or incidental damages. “Typical” parameters that may be
provided in Freescale data sheets and/or specifications can and do vary in different applications, and actual performance
may vary over time. All operating parameters, including “typicals,” must be validated for each customer application by
customer’s technical experts. Freescale does not convey any license under its patent rights nor the rights of others.
Freescale sells products pursuant to standard terms and conditions of sale, which can be found at the following address:
freescale.com/SalesTermsandConditions.
Freescale and the Freescale logo are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off.
SMARTMOS is a trademark of Freescale Semiconductor, Inc. All other product or service names are the property of their
respective owners.
© 2014 Freescale Semiconductor, Inc.
Document Number: AN4542
Rev. 2.0
12/2014
Similar pages