Text Message DJ – Reliability & Safety Team 22

Garrett Strzelecki

The Text Message DJ allows party guests the opportunity to choose which songs they want to hear. Guests can text the name of the sing they want and the Text message DJ streams the song from the internet. Other features include a voting process, strobing lights, and customizable options.

Component Failure Analysis Linear Voltage Regulators – SPX29302

Voltage regulators are prone to failing if not designed properly against the given voltage and the voltage it must supply

Microcontroller – ATxmega64A3U Brain of the device that may utilizes most every

UART/I2C port simultaneously.

TVS Array – SMF05C Used between with the GSM to provide transient

voltage protection to the SIM card and back. Spiked of up to 2 amps.

Criticality Levels High - The device causes harm or injury to

the user

Medium – Device ceases to function in its most desired operation mode. It no longer plays the songs requested.

Low – The device loses an included function, but still can play songs that are requested. DMX, light strobe, R/W to SD card no longer work

Voltage Regulator – SPX29302

Symbol

Parameter Value Description

λbBase Failure Rate 0.002 Voltage Regulator

ΠTTemperature Factor 5.1 125 C (Max)

ΠSElectrical Stress 1.0 Voltage Reg

constant

ΠCContact Construction 1.0 Metalurgically

bonded

ΠQQuality Factor 8.0 Plastic

ΠEEnvironment Factor 1.0 GB Ground, base

λP 0.0816 /106 Hours Failure Rate

Voltage Regulator Devices

λP = λbΠTΠSΠCΠQΠE

Microcontroller – ATxmega64A3U

Symbol Parameter Value Description

C1Die Complexity 0.14 8 bit

πTTemperature Coef. 0.95 85C (Max)

C2Pin Number Constant .032 64 pins

πEEnvironmental Constant 0.5 Ground base

πQQuality Factor 10 Commercial

screening

πLLearning Factor 1.5 1 year in

production (conservative)

λP 2.235 /106 Hours Failure Rate

MOS Devices Digital/Linear Gate/Logic Array

λP = (C1πT + C2πE)πQπL

Transient Voltage Suppressor – SMF05C

Symbol Parameter Value Description

λbBase Failure Rate 0.0013 TVS

ΠTTemperature Factor 14 125 C (Max)

ΠSElectrical Stress 1.0 TVS constant

ΠCContact Construction 1.0 Metalurgically

bonded

ΠQQuality Factor 8.0 Plastic

ΠEEnvironment Factor 1.0 GB Ground, base

λP 0.1456 /106 Hours Failure Rate

Transient Suppressor Devices

λP = λbΠTΠSΠCΠQΠE

FCMEC Chart

Failure No.

Failure Mode Possible Cause

Failure Effects

Criticality

Probability (λ/Hour)

1 Failure of Voltage Regulator

Chip burn out. Temperature too high with no heat sinks.

Incorrect, unregulated voltage into the device and components.

Medium 0.0816 /106

2 Failure of Microcontroller

Physical connection, incorrect software translation

Logic levels unpredictable

Medium 2.235 /106

3 Failure of Transient Voltage Supressor

High current draws from GSM

SIM card unprotected. May result in no longer sending or receiving texts

Medium 0.1456 /106