Marking of SMD resistors: designation of SMD resistors table online

Leadless design (SMD) resistors, like other components, require markings. From it you can get information about the resistor value and its accuracy. But in the case of SMD components, dimensions become a problem. It is impossible to apply a complete alphanumeric designation in a limited space. Marking in the form of color stripes is also not a solution - there is also not enough space to place the required number of tags. Determining the first familiarity location (where to start reading from) will also become a problem: a thickened line or a marking shifted to one side will also require additional space. Therefore, a special notation system has been adopted for leadless elements.

Three-digit resistor numbering with tolerances of 2%, 5% and 10%

If there are three symbols on the body of the device, this means that the resistor has an accuracy of 2% to 10%. There are two options for three-digit marking of electronic components - completely digital and alphanumeric designation.

Three digits

In most cases, the marking consists of three digits XYZ. They represent resistance in the form XY⋅10Z. An example of such a designation is 332. The first two digits mean 33 Ohms, and the third is the power to which the number 10 must be raised and then multiplied by 33. Simply this means the number of zeros that must be added to the right of the first two numbers. In this case, the marking means 3300 Ohm = 3.3 kOhm. If the third digit is zero, then there is no need to add anything (10=1). So, marking 100 means 10 Ohms (10×1). There are no decimal factors less than one (0.1 or 0.01) in this system.

Dimensions of SMD parts housings

SMD resistors

TYPE:	Type Explanation:
S.R.	Resistor Chip Resistor chip
Size (inches)	Size(mm)	Component Thickness	Tape width	Component pitch in the ribbon	Quantity in standard packaging (180 mm/7 inches) paper tape	Qty per standard package (180 mm/7 inches) plastic tape
01005	0402	0.12 mm ± 0.02	8 mm	2 mm	20000	–
0201	0603	0.23 mm ± 0.03	8 mm	2 mm	15000	–
0402	1005	0.35 mm ± 0.05	8 mm	2 mm	10000	–
0603	1608	0.45 mm ± 0.1	8 mm	4 mm	5000	–
0805	2012	0.55 mm ± 0.1	8 mm	4 mm	5000	–
1206	3216	0.55 mm ± 0.15	8 mm	4 mm	5000	–
1210	3225	0.55 mm ± 0.15	8 mm	4 mm	5000	4000
2010	5025	0.55 mm ± 0.15	8/12 mm	4/8 mm	–	4000
2512	6332	0.55 mm ± 0.15	12 mm	4/8 mm	–	4000/2000

TYPE:	Type Explanation:
SRM	Melf Resistor Melf resistor (round)
Size (inches)	Name	Component size	Tape width	Component pitch in the ribbon	Qty per standard package (180 mm/7 inches) plastic tape
0604	–	1.6 mm X 1.0 mm	8 mm	4 mm	3000
0805	Micro	2.2 mm X 1.1 mm	8 mm	4 mm	3000
1206	Mini	3.2 mm X 1.6 mm	8 mm	4 mm	3000
1406	Mini	3.5 mm X 1.4 mm	8 mm	4 mm	3000
2308	Melf	5.9 mm X 2.2 mm	12 mm	4 mm	1500

SMD capacitors

TYPE:	Type Explanation:
S.C.	Ceramic Chip Capacitor Ceramic chip capacitor
Size (inches)	Size(mm)	Component Thickness	Tape width	Component pitch in the ribbon	Quantity in standard packaging (180 mm/7 inches) paper tape	Qty per standard package (180 mm/7 inches) plastic tape
01005	0402	0.2 mm ± 0.03	8 mm	2 mm	20000	–
0201	0603	0.3 mm ± 0.03	8 mm	2 mm	15000	–
0402	1005	0.5 mm ± 0.1	8 mm	2 mm	10000	–
0603	1608	0.8 mm ± 0.1	8 mm	4 mm	4000	–
0805	2012	0.6 – 1.25 mm	8 mm	4 mm	4000	3000
1206	3216	0.6 – 1.25 mm	8 mm	4 mm	4000	3000
1210	3225	1.25 mm – 1.5 mm	8 mm	4 mm	–	3000
1812	4532	2 mm (Max.)	12 mm	8 mm	–	1000
2225	5664	2 mm (Max.)	12 mm	8 mm	–	1000

Tantalum capacitors SMD

TYPE:	Type Explanation:
SD	Molded Tantalum Tantalum capacitor (polar component)
Size (inches)	Code	Component Thickness	Component size	Tape width	Component pitch in the ribbon	Qty per standard package (180 mm/7 inches) plastic tape
3216	A	1.6 mm	3.2 mm X 1.6 mm	8 mm	4 mm	2000
3528	B	1.9 mm	3.5 mm X 2.8 mm	8 mm	4 mm	2000
6032	C	2.5 mm	6.0 mm X 3.2 mm	12 mm	8 mm	500
7343	D	2.8 mm	7.3 mm X 4.3 mm	12 mm	8 mm	500
1608	J	0.8 mm	1.6 mm X 0.8 mm	8 mm	4 mm	4000
2012	P/R	1.2 mm	2.0 mm X 1.2 mm	8 mm	4 mm	2500/3000

Electrolytic capacitors SMD

TYPE:	Type Explanation:
S.E.	Aluminum Capacitor Aluminum capacitor (polar component)
Case diameter	Case height	Tape width	Component pitch in the ribbon	Qty per standard package (180 mm/7 inches) plastic tape	Qty per standard pack (330 mm/13 inches) plastic tape
3 mm	5.5 mm	12 mm	8 mm	100	2000
4 mm	5.5 mm	12 mm	8 mm	100	2000
5 mm	5.5 mm	12 mm	12 mm	100	1000
6.3 mm	5.5 mm	16 mm	12 mm	100	1000
8 mm	6 mm	16 mm	12 mm	100	1000
8 mm	10 mm	24 mm	16 mm	100	500
10 mm	10 mm	24 mm	16 mm	100	300 – 500
10 mm	14 – 22 mm	32 mm	20 mm	–	250 – 300
12.5 mm	14 mm	32 mm	24 mm	–	200 – 250
12.5 mm	17 mm	32 mm	24 mm	–	150 – 200
12.5 mm	22 mm	32 mm	24 mm	–	125 – 150
16 mm	17 mm	44 mm	28 mm	–	125 – 150
16 mm	22 mm	44 mm	28 mm	–	75 – 100
18 mm	17 mm	44 mm	32 mm	–	125 – 150
18 mm	22 mm	44 mm	32 mm	–	75 – 100
20 mm	17 mm	44 mm	36 mm	–	50

SMD transistors

TYPE:	Type Explanation:
SOT	SOT Transistor SOT transistor
Type of shell	Number of pins	Tape width	Component pitch in the ribbon	Case size A (mm)	Case size B (mm)	Case size S (mm)	Case height H (mm)	Qty per standard package (180 mm/7 inches) plastic tape
SOT723	3	8 mm	4 mm	1.2	0.8	1.2	0.5	8000
SOT346	3	8 mm	4 mm	2.9	1.6	2.8	1.1	3000
SOT323	3	8 mm	4 mm	2.0	1.25	2.1	0.9	3000
SOT416	3	8 mm	4 mm	1.6	0.8	1.6	0.7	3000
SOT523F	3	8 mm	4 mm	1.6	0.8	1.6	0.7	3000
SOT23	3	8 mm	4 mm	2.9	1.3	2.4	0.95	3000
SOT23-5	5	8 mm	4 mm	2.9	1.6	2.8	1.1	3000
SOT23-6	6	8 mm	4 mm	2.9	1.6	2.8	1.1	3000
SOT89	3	12 mm	8 mm	4.5	2.5	4.0	1.5	1000
SOT143	4	8 mm	4 mm	2.9	1.6	2.8	0.95	3000
SOT223	3	16 mm	8 mm	6.5	3.6	7.0	1.6	2500
SOT323	3	8 mm	4 mm	2.0	1.25	2.1	0.9	3000
SOT343	4	8 mm	4 mm	2.0	1.25	2.1	0.9	3000
SOT353	5	8 mm	4 mm	2.0	1.25	2.1	0.9	3000
SOT363	6	8 mm	4 mm	2.0	1.25	2.1	0.9	3000
SOT23-8	8	8 mm	4 mm	2.9	1.6	2.9	1.2	3000

Power transistors SMD

TYPE:	Type Explanation:
DPAK	DPAK Transistor DPAK Transistor
Type of shell	Number of pins	Tape width	Component pitch in the ribbon	Case size L (mm)	Case size W (mm)	Case height H (mm)	Case size S (mm)	Qty per standard pack (330 mm/13 inches) plastic tape
DPAK	3	16 mm	8 mm	6	6.5	2.3	10	2500
D2PAK	3	24 mm	16 mm	9.2	10	4.4	15	500 – 800
D2PAK-5	5	24 mm	16 mm	9.2	10	4.4	15	500 – 800
D2PAK-7	7	24 mm	16 mm	9.2	10	4.4	15	500 – 800
D3PAK	3	24 mm	24 mm	14	16	4.7	18.8	500

MELF SMD diodes

TYPE:	Type Explanation:
SOD	SOD, SM, Melf Diode/Rectifier SOD, SM, Melf diodes (round)
Component type	Component size (diameter X length)	Tape width	Component pitch in the ribbon	Qty per standard package (180 mm/7 inches) plastic tape
MiniMELF/SOD-80 (LL34)	1.6 mm X 3.5 mm	8 mm	4 mm	2500
MELF (LL35/LL41)	2.5 mm X 5.0 mm	12 mm	4 mm	1500
MELF (SM1)	2.5 mm X 5.0 mm	12 mm	4 mm	1750

SOD SMD diodes

TYPE:	Type Explanation:
S.M.	Rectangular Diode Gull Wing Lead
Type of shell	Tape width	Component pitch in the ribbon	Case size L (mm)	Case size W (mm)	Case height H (mm)	Case size S (mm)	Case size B (mm)	Qty per standard package (170 mm/7 inches) plastic tape
SOD923	8 mm	2 mm	0.8	0.6	0.4	1.0	0.2	8000
SOD723	8 mm	2 mm	1.0	0.6	0.5	1.4	0.3	8000
SOD523	8 mm	4 mm	1.2	0.8	0.6	1.6	0.3	3000
SOD323	8 mm	4 mm	1.7	1.25	0.7	2.5	0.3	3000
SOD123	8 mm	4 mm	2.7	1.5	1.3	3.6	0.7	3000
DO215AC	12 mm	4 mm	4.3	2.6	2.2	6.1	1.4	1800
DO215AA	12 mm	8 mm	4.3	3.6	2.3	6.2	2.0	1000
DO215AB	16 mm	8 mm	7.0	6.0	2.3	1 0	3.0	900

SM SMD Diodes

TYPE:	Type Explanation:
S.M.	Rectangular Diode C-Bend Lead (Modified J-Lead)
Type of shell	Tape width	Component pitch in the ribbon	Case size L (mm)	Case size W (mm)	Case height H (mm)	Case size S (mm)	Case size B (mm)	Qty per standard package (170 mm/7 inches) plastic tape
S.M.A.J.	12 mm	4 mm	4.3	2.6	2.2	5.0	1.5	1800
SMBJ	12 mm	8 mm	4.3	3.6	2.3	5.4	2.0	750
SMCJ	16 mm	8 mm	7.0	6.0	2.3	8.0	3.0	850

Marking of SMD resistors according to EIA-96

The four-digit designation of resistor parameters is not the optimal method. Still, there is not enough space for four characters on small-sized cases. Therefore, for devices with an accuracy of 1% for form factors below 0805, a different marking system is used, consisting of two numbers and an alphabetic symbol. This designation is introduced by the EIA -96 , according to which two numbers indicate the nominal value in ohms, and the letter indicates the multiplier.

Table of codes and resistor marking values

In the EIA-96 standard, there is no direct correspondence between the marking numbers and the denomination. The actual resistance value is associated with a code. To determine the resistance value, you need to refer to the table:

Table 1. Table of codes and resistor marking values according to EIA-96.

So, code 20 corresponds to a value of 158 Ohms, and code 69 - 511. Obviously, it is very difficult to remember the correspondence between the code and the nominal value. Therefore, it is recommended to use a table or an online calculator.

Multiplier table

The multiplier table is smaller, but also non-obvious and difficult to remember:

Methods for determining resistor resistance

If there is no alphanumeric marking, you can use one of the following methods:

The simplest method is to determine the denomination from the documentation. This is easiest to do if the part is purchased separately and has an accompanying document. If a resistor is part of an electrical apparatus, then its characteristics are indicated on the general electrical diagram either directly next to it (to the right or below) or below in the specification.
If the resistor is a separate part, then its resistance can be measured with an ohmmeter or multimeter.
It is possible to accurately identify a part contained in the device only after it has been desoldered.

Examples of decoding alphanumeric markings of SMD resistors

To determine the resistor parameter, it is not necessary to memorize tables of values. There are many online calculators on the Internet, and many offline programs are also available for download. But if you understand the principles of marking, it is possible to determine the values of resistance and accuracy without resorting to reference books; after a little training, this is obtained at first glance. To consolidate your understanding of the basics, you need to look at several practical examples.

Resistors 101, 102, 103, 104

In all these examples, the numerical value of the resistance is the same, equal to 10, but the multipliers in each case are different:

101 - 10 Ohms must be multiplied by 101, that is, by 10, or added to the value of one 0 - the total will be 100 Ohms;
102 - 10 Ohms must be multiplied by 102, that is, by 100, or two zeros must be added to the value - you get 1000 Ohms (= 1 kOhm);
103 - 10 Ohms must be multiplied by 103, that is, by 1000, or three zeros must be added to the value - you get 10,000 Ohms (= 10 kOhms);
104 - 10 Ohms must be multiplied by 104, that is, by 10,000, or four zeros must be added to the value - you get 100,000 Ohms (= 100 kOhms).

It is easy to remember that for a three-character encoding, the last digit 3 indicates kilo-ohms, and 6 - mega-ohms - this will further facilitate visual reading of the marking.

Resistors 1001, 1002, 2001

If there are 4 digits on the body of an electronic component, this means that its accuracy is at least 1%. And the denomination also consists of a mantissa and a multiplier, which is specified by the last symbol:

1001 - 100 Ohms must be multiplied by 101, that is, by 10, which is equivalent to adding one zero to the mantissa - the result will be 1000 Ohms (1 kOhm);
1002 – the mantissa is also equal to 100 Ohm, but the multiplier is equal to 102=100 (two zeros must be added), and the nominal value will be equal to 10000 Ohm=10 kOhm;
2001 - in this case, 200 Ohms must be multiplied by 101 = 10, the nominal value is 2000 Ohms = 2 kOhms.

Types of SMD capacitors

Every radio amateur needs to understand the types of capacitors mounted using the surface-mount method. Such products may differ not only in capacity, but also in voltage, so ignoring the conditions for using parts can lead to their failure.

Electrolytic components

Electrolytic SMD capacitors do not differ fundamentally from standard products. Such electronic components most often take the form of barrels, in which a thin metal rolled into a cylinder is located under an aluminum housing, and a solid or liquid electrolyte is located between it.

Electrolytic SMD capacitors

The main difference between such a part and a standard electrolytic cell is that its contacts are mounted on a flat dielectric substrate. Such products are very reliable in operation, especially convenient when it is necessary to install a new product with minimal time investment.

In addition, during soldering the product does not overheat, which is very important for electrolytic capacitors

Ceramic components

In ceramic elements, porcelain or similar inorganic materials are used as a dielectric. The main advantage of such products is their resistance to high temperatures and the ability to produce products of extremely small sizes.

Important! SMD ceramic capacitors are also installed by soldering onto a printed circuit board. Visually, such an element, as a rule, resembles a small brick to which contact pads are soldered at the ends

Visually, such an element, as a rule, resembles a small brick to which contact pads are soldered at the ends

Visually, such an element, as a rule, resembles a small brick to which contact pads are soldered at the ends.

Ceramic SMD capacitors

Unlike radio components of standard sizes, SMD elements of small size are first glued to the board, and only then the leads are soldered. In production, ceramic products of this type are installed by special automatic machines.

Marking of tantalum SMD capacitors

Tantalum SMD capacitors are resistant to increased mechanical loads. Such products can also be made in the form of a small parallelepiped, to which contact leads are soldered on the sides. Tantalum is a very durable metal with high ductility. Foil made of this material can have a thickness of hundredths of a millimeter.

For your information! Due to the presence of certain physical properties based on tantalum, it is possible to produce radio components of the highest precision.

Tantalum capacitors

Tantalum capacitors, as a rule, have small housing sizes, so it is not always possible to apply full markings to products made in an “A” size housing. Knowing the designation features of radio components of this type, you can easily determine the rating of the product. The maximum permissible voltage in volts for tantalum products is indicated in Latin letters:

G - 4;
J - 6.3;
A - 10;
C - 16;
D - 20;
E - 25;
V - 35;
T - 50.

Note! The capacity of the products is indicated in microfarads after the letter “μ”, and the positive contact is indicated with a thick line

Coding table for planar SMD parts

The first pairs of digits of the SMD component marking are indicated. You need to click on them, after which a page will open with another table, which contains combinations of other symbols. A brief description of the functions and parameters is also provided.

A.A.

A.C.

A.E.

A.F.

A.G.

A.H.

A.I.

A.J.

A.K.

A.M.

A.W.

B.A.

B.C.

B.F.

B.G.

B.H.

B.I.

B.J.

B.K.

B.L.

B.M.

B.P.

B.S.

B.U.

B.V.

B.W.

C.A.

C.B.

C.E.

C.G.

C.I.

C.J.

C.L.

C.M.

C.P.

C.Q.

C.S.

C.T.

C.U.

C.Y.

D.A.

D.B.

D.H.

D.I.

D.L.

D.P.

D.R.

D.S.

D.T.

D.U.

D.V.

E.A.

E.B.

E.C.

E.E.

E.F.

E.G.

E.H.

E.K.

E.M.

E.P.

E.W.

F.A.

F.C.

F.E.

F.J.

F.T.

F.U.

F.V.

G.B.

G.C.

G.D.

G.E.

G.H.

G.I.

G.J.

G.L.

G.M.

G.P.

G.S.

G.U.

G.V.

G.W.

G.Y.

H.A.

H.J.

H.K.

H.L.

H.M.

H.S.

H.V.

I.A.

I.B.

I.E.

I.G.

I.M.

J.M.

J.P.

J.Q.

J.U.

K.A.

K.B.

K.M.

L.A.

L.C.

L.E.

L.H.

L.J.

L.K.

L.M.

L.Q.

L.S.

L.U.

M.A.

M.B.

M.C.

M.D.

M.E.

M.F.

M.H.

M.L.

M.R.

M.T.

M.U.

M.W.

M.Y.

N.A.

N.B.

N.H.

N.K.

N.M.

N.Q.

N.S.

N.V.

P.B.

P.D.

P.E.

P.I.

P.J.

P.L.

P.M.

P.T.

P.U.

Q.J.

R.A.

R.B.

R.C.

R.D.

R.I.

R.J.

R.L.

R.M.

R.P.

R.R.

R.S.

R.Y.

S.A.

S.B.

S.C.

S.E.

S.G.

S.I.

S.J.

S.K.

S.M.

S.Q.

S.R.

S.U.

S.W.

S.Y.

T.A.

T.D.

T.E.

T.H.

T.I.

T.J.

T.Q.

T.S.

T.U.

T.Y.

U.A.

U.C.

U.F.

U.G.

U.J.

U.M.

U.P.

U.W.

V.A.

V.C.

V.D.

V.E.

V.J.

V.M.

V.P.

V.V.

W.A.

W.B.

W.C.

W.D.

W.F.

W.G.

W.H.

W.J.

W.K.

W.L.

W.M.

W.P.

W.Q.

W.S.

W.T.

W.U.

W.V.

W.X.

W.Y.

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