Teledyne Tablet Accessory T803 Manual De Usuario

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A Primer on Electro-Static Discharge 
Teledyne API T803 CO2/O2 Analyzer Operation Manual 
226 
 
Walking across nylon carpet 
1,500V 
35,000V 
Walking across vinyl tile 
250V 
12,000V 
Worker at bench 
100V 
6,000V 
Poly bag picked up from bench 
1,200V 
20,000V 
Moving around in a chair padded 
with urethane foam 
1,500V 18,000V 
13.2. HOW ELECTRO-STATIC CHARGES CAUSE DAMAGE 
Damage to components occurs when these static charges come into contact with 
an electronic device.  Current flows as the charge moves along the conductive 
circuitry of the device and the typically very high voltage levels of the charge 
overheat the delicate traces of the integrated circuits, melting them or even 
vaporizing parts of them.  When examined by microscope the damage caused by 
electro-static discharge looks a lot like tiny bomb craters littered across the 
landscape of the component’s circuitry. 
A quick comparison of the values in Table 13-1 with the those shown in Table 
13-2, listing 
device susceptibility levels, shows why Semiconductor Reliability 
News
 estimates that approximately 60% of device failures are the result of 
damage due to electro-static discharge. 
Table 13-2:  Sensitivity of Electronic Devices to Damage by ESD  
DAMAGE SUSCEPTIBILITY VOLTAGE 
RANGE 
DEVICE 
DAMAGE BEGINS 
OCCURRING AT 
CATASTROPHIC 
DAMAGE  AT 
MOSFET
10 100 
VMOS
30 1800 
NMOS
60 100 
GaAsFET
60 2000 
EPROM
100 100 
JFET
140 7000 
SAW
150 500 
Op-AMP
190 2500 
CMOS
200 3000 
Schottky Diodes
300 
2500 
Film Resistors
300 
3000 
This Film Resistors
300 
7000 
ECL
500 500 
SCR
500 1000 
Schottky TTL
500 
2500 
Potentially damaging electro-static discharges can occur:  
Any time a charged surface (including the human body) discharges to a device.  
Even simple contact of a finger to the leads of a sensitive device or assembly can 
allow enough discharge to cause damage.  A similar discharge can occur from a 
charged conductive object, such as a metallic tool or fixture.   
07276B DCN6418