How is a computer component commonly marked for identification
SMD Resistor Coding Explained
[Music]
assembly resistors are the most widely
used type of resistors among the
different resistors and these type of
resistors are used in the production of
various electronic equipments like
televisions smartphone and even
high-tech R&D equipments now if you
closely observe the printed circuit
boards of these electronic equipments
then you will find that the small code
is written on top of this surface mount
resistors so basically this code defines
the value of these resistors so now in
this video let us find out how we can
decode this code and from this how we
can find the value of this surface mount
resistors now usually the three types of
coding schemes are used for this surface
mount resistors so let us see them one
by one
so the first type of coding scheme is
the three-digit coding scheme so in this
scheme the 3 digits are used to define
the value of the resistors now out of
the three digits the first two digits
defines the two most significant digits
of the resistor value while the third
digit defines the multiplying factor for
the resistor value so now let us take
some examples for this three digit
coding scheme so for example if the code
that is written on this assembly
resistor is 223 it means that the value
that is represented by this resistor is
equal to 22 into 10 to the power 3 that
is equal to 22 kilo ohm so here the last
digit is 3 it means that the value would
be multiplied by the 10 to the power 3
and hence the value is equal to 22 kilo
similarly for the core of 430 the value
of the resistor would be equal to 43
into 10 to the power 0 that is equal to
43 ohm and likewise if the code that is
written on the resistor is 3 0 5 it
means that the value of the resistor
would be equal to 30 into 10 to the
power 5 that is equal to 3 macao now
sometimes in these three digit coding
schemes the later R is used to define
the position of the decimal point so for
example
the code that is written on the register
is who are two it means that the value
of the resistor is equal to two point
two ohm and likewise for the code of r39
the value of the register would be 0.39
ohm so basically this later R is used to
define the position of the decimal point
so in this way by using this three digit
code we can find the resistor value so
now similarly let us see the four digit
coding scheme so this type of coding
scheme is also very similar to the 3d
coding scheme so in this a four digit
coding scheme out of the four digits the
first three digits defines the three
most significant digits of the register
value while the last digit defines the
multiplying factor for this resistor
value so let us take some examples for
this four digit coding scheme so for
example if the core that is written on
the surface mount of this term is 1 0 0
1 it means that the value of the
register would be 100 into 10 to the
power 1 that is equal to 1 kilo and
similarly for the case of Phi 1 0 3 the
value of the resistor would be Phi 1 0
into 10 to the power 3 that is equal to
Phi 1 0 kilo so in this way by using
this four digit coding scheme we can
find the resistor value now in this four
digit coding scheme also the later R is
used to define the position of the
decimal point so for example if the code
that is written on the resistor is two
or seven zero it means that the value of
the resistor would be equal to two point
seven ohm and likewise if the code that
is written on the resistor is 0 or 2 4
then the value of the resistor would be
point 2 4 ohm now many times in the PCB
assembling this assembly jumpers are
also used now theoretically the
resistance of this assembly jumpers used
to be a zero so whenever you find this
type of force that is written on the
surface mount resistors it means that
the value of this resistor is equal to
zero now apart from these three and four
digit coding schemes for the high
precision resistors this third type of
coding scheme is also used so this type
of coding scheme is used for the
resistors
which has a 1% of Tolerance so in this
game three characters are used to define
the register value now out of the three
characters the first two characters used
to be a number and last character used
to be a later so these first two digits
defines the three most significant
digits of the register value while the
last later is to define the multiplying
factor for the register value so here is
a table which defines the different
codes for the last letter and the
corresponding multiplying factor and
here is the another table which defines
the first two digits of the code and the
corresponding value that is represented
by this first two digits so using these
two tables we can find the value of the
resistor for this type of coding scheme
so now let's say we have one register
and the code that is written on this
resistor is 3 6 C now if you look this
code the first two digits of this code
is 36 in the corresponding value that is
represented by that code is 232 and the
last letter of these code is C so the
multiplying factor for this register
would be equal to 100 so from this we
can say that the value of the register
would be equal to 232 multiplied by 100
that is equal to 23 point two kilo so in
this way by using these two tables we
can find the value of the register so
let us take few more examples so that it
will get clear to you so let us say we
have one more resistor and the code that
is written on the register is 0 5 Y now
from the first two digits of this code
we can say that the value that is
represented by this code is equal to 1 1
0 and here the last letter is Y so the
corresponding multiplying factor is
equal to point zero 1 so from these two
tables we can say that the value of the
register will be equal to 1 1 0
multiplied by point 0 1 that is equal to
1 point 1 ohm so similarly let us take
one more example so if the code that is
written on the resistor is 48 D then we
can say that the value of the resistor
will be equal to still is 0 9 multiplied
by thousand so the value of the resistor
would be equal to 3 0 9 hello so in this
way
by using these two tables we can find
the value of the resistor for this type
of coding scheme so I hope in this short
tutorial you understood how to find the
value of the surface mount resistors
from the code that is written on these
resistors so if you have any question or
Sedition do let me know in the comment
section below if you like this video hit
the like button and subscribe the
channel for more such videos
[Music]
