Tektronix 576 - Page 33

OR EMIT I NPU T con n ecto r . Wh
en
t h
e Terminal Selector
switc h is set to BAS E T ERM S H O R T,
t he base terminal is
sh orte d to t h
e
emitter
.
In t he B AS E G R O UN D E D range, t he base terminal is
con n ecte d to gro u nd and t h e Te r minal Selector switc h d
e-
termines t
he
state of t he emitter terminal
.
W it
h
t
h e
switc h
set to ST
EP
G EN, t
he
Ste
p
Generator output is inverte d
an d a pp
lie
d to t
he
emitter terminal
.
Wh en t h
e
switc
h
is set
to OPEN (O R ΕΧΤ ) t h
e
emitter termi
n
al is left
open
. In
t h is case, measurements may be ma d e with t h e emitter ter-
minal left o p en or wit h an externally generated signal
a pp
lied
to it
t h
ro
ugh
t
h e ΕΧΤ
B AS
E
O R EMIT I NPU T
connector .
Te k tronix Ty pe 576 device testing accessories
3
may
be
p lugge d into t h e 10 Accessories
connectors provi d e d on t he
Stan d ar d Test F ixt u re . T h ese accessories
provi d e soc k ets
into w h ic h semicon d uctors wit h various lead
a rr angements
may be place d for testing . T he 10 Accessories
connectors
allow
t he setting
up
of two devices at α time for com p arison
testing . T
he LEF T-O FF-R IG H T switc h d etermi n es w h ic h
device is und er test . T h e 10 Accessories con nectors also
3
So
m e o f t h ese accessories are made o f plast i c and are s u sce p tib l e
to da m age f rom excess i ve h eat . If α device is li k el y to h eat exces-
s i ve l y α h eat s i nk or t h e pul sed ste p s mode o f operation s h o ul d be
u sed .
1
Μαγ
be
inverted
by pressing t h e P O LA R I TY IN V ERT button .
acce p t stan da r d banana p lugs so t h at α d evice may be con -
necte
d to
t he Ty p e
576 wit
h
o
u
t using α s p ecific device
testi ng accessory .
T he unlabele d Accessories
co n nectors
allow K
elvin
sensing of voltage und
er h
ig h current
con
d itions . K
elvin
sensing means t
h
at voltage
measurements
on t
h e
collector
and t h e emitter terminals of α device und
er
test are ma d
e
t h ro ugh separate contacts to t h e device lea d s w h ic h re d uce
con tact resistance .
T h
e
ST
EP G EN O UT PU T connector allows t he Ste p
Ge n erato r ou t p ut to be use d exte r nally . T h e ΕΧΤ B AS E
O R EMIT I NPU T connector allows a pp lication of an ex-
ter n ally generate
d signal to eit h er t he base or t he emitter of
t
h e
d
evice unde r test . T h e exte r nal signal is app lie d to
w h ic h eve r terminal is c hosen by t he Terminal Selector
switc h . T h e G R O UN D connector p r ovi d es α Ty pe 576
g r oun d reference for signals generate d or use d exte r nal i n
Ty p e 576 .
P olarities of t h e Collector Su pp ly an d Ste p Genera-
tor Out p ut
Table
2-7 s h ows t he pola r ities of t he Collector Su pp ly
an
d
t
he Ste p Gene r ator outp ut fo r various settings of t he
Collector Su pp ly PO L A R ITY switc h an d t he Terminal Se-
lector switc h .
TA BLE 2-7
P olarities of t h e Collector S u pp
ly
an
d
Step Generator Out pu
t
O p erati n g I n
st
r uctions-Ty p
e 576
Switch es
P
ola
r ities
Collector Su pp ly POLARITY Terminal Selector
Collector Su pp ly Step Generator
-( ΡΝΡ ) EM ITT ER G R O UN D E D N egative going Negative going
i
-( ΡΝΡ )
BAS E G R O UN D E D N egative going Positive going
+( ΝΡΝ )
EM ITT ER G R O UN DED Positive going Positive going
i
+(
ΝΡΝ )
B AS E G R O UN D E D Positive going N egative goi ng
AC
EM ITT ER G R O UN DED P ositive a n d
N egative going
Positive goi n g s
AC
BAS EGR O UN D E D P ositive an d
N egative going
N egative going