Testing Instruements.

1. Welcome
E
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C
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P
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2. TESTING
INSTRUMENTS

3. TOPICS TO BE COVERED
 Working Of Digital IC Tester
Working Of Logic Analyzer
Working Principle of Spectrum Analyzer
Working Of Logic Probe
4
Topics

4. Digital IC Tester
 The basic function of the digital IC tester
is to test a digital IC for correct logical
functioning as described in the truth table
and/or function table.
 It can test digital ICs having a maximum of
24 pins. Since it is programmable, any
number of ICs can be tested within the
constraint of the memory available.

5. Block Diagram Of Digital Tester
System
Clock
Initializatio
n
Network
Device
Under Test
Thumb Wheel
Switches
System
Clock
Address
Generator
Test
Pattern
Generator
Multiplexer
CMOS Clock
TTL Clock

6. Working
 The IC to be tested is inserted in the base.
 The user enters the IC number through keypad which is
simultaneously displayed on the LCD.
 The IC number is communicated to other MCU which basically test
the ICs for few sets of input which is given through the MCU and
corresponding output.
 The result is again communicated to the first MCU confirming it to be
either correct or faulty which is displayed on the LCD.
 If the IC tested is ok “IC TESTED OK” is displayed on the LCD.
Otherwise “IC TESTED FAILED” is displayed.

7. Logic Analyzer

8. Block Diagram Of Logic Analyzer
System
under
test
Input
conditione
r
Trigger
pattern
recognizer
Trigger
controller
Display
controller
High
speed
recording
memory
subsystem
Asynchronou
s clock
generator
Display
formatter
X Y Z
Ext. Arm
Ext. Trigger
Data
Qual
Clock
Qual
Trigger

9. Spectrum
Analyzer
1. A spectrum
analyzer measures the
magnitude of an input signal
versus frequency within the
full frequency range of the
instrument.
2. The primary use is to
measure the power of the
spectrum of known and
unknown signals.
Spectrum analyzers are used for
many measurements including:
 Frequency Response, Noise and
Distortion characteristics of all
kinds of radio-frequency circuitry
 Occupied Bandwidth and
Interference Sources in
Telecommunications
 Basic Pre-Compliance Testing for
EMC Testing

10. Parallel Filter Bank
Analyzer
Filter
Filter
Filter
Input v(t)
Out put
Out put
Out put

11. Amplitude
Time
Over Lapping Filter Bank

12. Input Mixer
IF
Amplifier
Detector
and video
amplifier
Voltage
Tuned
oscillator
Saw tooth
generator
Spectrum
fmin fmax
Block Diagram Of Spectrum
Analyzer

13. Amplitude
Amplitude
Amplitude
Time
Time
Time
(a) Test wave seen on ordinary CRO
(b) Display on the spectrum CRO
(c) Test wave form as seen on X-axis
(Time) and z-axis (Frequency)
f 2f
f 2f
A1
A2
Frequency

14. A
P
L
I
C
A
T
I
O
N
S
Frequency
Modulation
Amplitude
Modulation
Pulse Modulation
Harmonic Distortion

15. Logic
Probe
 A logic probe is a low-cost hand-held test probe used for
analyzing and troubleshooting the logical states (boolean 0 or
1) of a digital circuit. When many signals need to be observed
or recorded simultaneously, a logic analyzer is used instead.
 Typically logic probes are used to test digital circuits like those
using TTL or CMOS logic.
 The logic probe is normally powered by the circuit under test -
there are normally leads with crocodile / alligator clips that can
be attached to the ground and supply of the circuit under test.

16.  A logic probe normally may be capable of indicating
up to four different states:
 Logic High
 Logic Low
 Pulses
 Line Tri- Stated
 There are three connections to the logic probe:
 Black Lead with Crocodile Clip
 Red Lead with Crocodile Clip
 Probe

17. LOGIC PROBE

18. Advantages Disadvantages
Low Cost
Can Test only single
signal at a time.
Poor
Display
Easy to Use

19. Thank You