Kian Hui Wong
Chia Siong Goh
Wan Qi Choo
Jun Jun Peh
Presenter: Kian Hui Wong
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An 8x8 grid-based music synthesizer made with a button pad at the top
and some LEDs at the bottom
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Produces sound and emits light (LED) when user touches the buttons
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3 music playing modes:
• Sweep mode
• Gravity mode
• Memory mode
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Several different types of sound:
• Guitar, Piano, and Drum beats
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Microcontroller (PIC18F64K22)
Switching Regulators(LM2675-5,LM2675-3.3)
LED driver(AS1116)
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High complexity (64 pin, 8 bit)
Controls LCD, buttons input, audio, LED
drivers, accelerometer.
λp
=(C1πT+C2πE)πQπL
=(0.14*0.98+.032*4)10*1
=2.652 Failures/106Hours
MTTF =106/λp
=377074 hours≈43 years
Parameter name
Description
Value
Comments
C1
Die complexity
0.14
8-bit microprocessor
πT
Temperature
coefficient
0.98
C2
Package Failure
Rate
0.032
πE
4.0
πQ
Environmental
constant
Quality factor
πL
Learning factor
1.0
Worst case
18mA,VDD=3.3V,FOSC
=64MHz, 85°C
64pins, non
hermetic SMT
leaded
Ground, Mobile,
handheld equipment
Other Commercial
or Unknown
Screening Levels
In production for 3
years, >2yrs
10.0
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Possible high temperature
15V unregulated input
3.3V, 1Amax regulated output
λp
=(C1πT+C2πE)πQπL
=(0.02*2.8+0.0034*4)10*1
=0.696 Failures/106Hours
MTTF =106/λp
=1436782 hours≈164 years
Parameter name
Description
Value
Comments
C1
Die complexity
0.02
πT
Temperature
coefficient
2.8
C2
0.0034
πQ
Package Failure
Rate
Environmental
constant
Quality factor
πL
Learning factor
1.0
Estimated 101-300
transistors MOS
(Linear)
-40°C< Junction
Temperature<125°
C, assume <70°C
8pins, non hermetic
SMT leaded
Ground, Mobile,
handheld equipment
Other Commercial
or Unknown
Screening Levels
In production more
than 2 years
πE
4.0
10.0
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Possible high temperature
3.3V, 335mAtypical when all LEDs are lighted
λp
=(C1πT+C2πE)πQπL
=(0.4*0.6+.011*4)10*1
=2.84 Failures/106Hours
MTTF =106/λp
=352113 hours≈40 years
Parameter name
Description
Value
Comments
C1
Die complexity
0.40
πT
Temperature
coefficient
0.6
C2
Package Failure
Rate
0.011
πE
4.0
πQ
Environmental
constant
Quality factor
πL
Learning factor
1.0
Estimated 1001 3000 transistors
MOS (Digital)
-40°C< Junction
Temperature<125°
C, assume <70°C
24pins, non
hermetic SMT
leaded
Ground, Mobile,
handheld equipment
Other Commercial
or Unknown
Screening Levels
In production more
than 2 years
10.0
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High- Possibility of injury to user
Medium-Device not working, not repairable
Low- Majority of device still working and can
be repaired easily
Failure mode
Possible causes
Effect
Detection method
Criticality
Power supply
unregulated
Failure of
LM2675
switching
regulator, poor
soldering, bypass
capacitor failure
Possible damage
to most
components due
to overheat
Temperature raises
beyond working
range,
Smell of burning,
Probe PCB power
traces
High
Battery deepdischarged
Battery fuel
gauge failure,
Microcontroller
USART failure
Explosion, fire,
shorten battery
lifecycle
Battery gets
overheated
High
Microcontroller Bypass
not working
capacitors
shorted or not
connected, bad
soldering
All subsystems
are no longer
able to
communicate
with each other
Observation,
Program(if possible)
and toggle every IO
pins
LowMedium
Failure mode
Possible causes
Effect
Detection method
Criticality
LEDs are not
lighted up
LED drivers failure,
current limiting
resistor shorted
LEDs not lighted Observation (visual)
up, LEDs will be
burnt
Speaker is
not
outputting
sound
DAC IC failure,
Amplifier IC failure
Speaker and
audio jack fail
to work
Observation
Low
(hearing), Probe for
audio output,
compare between
MIDI output and DAC
output
Button pad
not working
Button pad
conducting pad is
worn out,
Microcontroller
failure, Poor
soldering, Buttons
diode failure
Buttons are not
detected when
pressed
Observation (visual),
check connection of
button pads
Low
Low