Common Items

Q-1

I cannot tell if the package drawing of a 3-pin power mini mold (SC-62) is the top view or the bottom view.

A-1

The bottom view is shown so that it is easy to recognize the pin shapes of the collector and source at the center.

(2007/04)

Q-2

Please tell me how to find the pin 1 position in a 4-pin or 6-pin package.

A-2

When placing the package in a direction that you can read the marking, Pin 1 is the pin in the bottom left corner.
In the RF & microwave products, the Pin 1 position varies from one product to another. Refer to the data sheet of each product.

(2007/04)

Q-3

Are SC-62 and SOT-89 the same?

A-3

SC-62 is the name given by the Electronic Industries Association of Japan (EIAJ) and SOT-89 is the name given by Joint Electronic Device Engineering Council (JEDEC, an American industrial organization) that promotes standardization of electronic components). Although the names differ, the package shapes are the same.

(2006/10)

Q-4

Does NEC Electronics have its own original name for a discrete package?

A-4

MP-**, for a package relating to a power device, is the original name given by NEC Electronics.

(2006/10)

Q-1

What is the operating temperature range of transistors, diodes, etc.?

A-1

Among semiconductor products, integrated circuit products are useless if their circuits do not function, and therefore the (circuit) operating temperature range is specified.
Discrete devices such as transistors and diodes do not by themselves have circuit functions, and therefore no operating temperature range is specified for them.
Use such products within the storage temperate range.

The lower limit of the usage temperature range is the storage temperature range, but the upper limit is restricted by the junction temperature.
For example, if the absolute maximum rating for the junction temperature is 150 °C, such as in a transistor, perform derating so that the junction temperature does not exceed 150 °C.

Q-1

We may on occasion use packages such as the TO-220 with a fin attached to the package for heat dissipation purposes.
We would like to know the withstand voltage of packages as a voltage of about 1.5 KV is supplied to the cooling fin in such cases.

A-1

Unfortunately, the withstand voltage of the TO-220 and other packages has not been measured.
Please request this information from your authorized NECEL distributor.

Q-1

What is the meaning of the letters "JM" at the end of the part number "2SD1701-AZ/JM" on the product label?
Does the package of this product differ from a standard product?

A-1

"JM" indicates the country (or countries) in which the product was manufactured.

First letter… Country in which diffusion process was carried out: J = Japan
Second letter…Country in which assembly process was carried out: M = Malaysia

This product is also a standard product, and therefore there are no differences in the packages and characteristics.

(2006/03)

Q-2

Upon purchasing the 2SD1694, I requested a "K" rank product, but the label on the product says "KM".
Is this actually a "K" rank product? What is the meaning of "M" in this case?

A-2

Products described as "KM" are "K" rank products. "M" is an internal control symbol used by NEC Electronics whose meaning cannot be disclosed publicly.

(2006/03)

Q-3

What is the meaning of the letter "L" that is described in the part number of the 3-pin minimold product (Sc-59) that I ordered?

A-3

Generally, "L" means magazine packing container.
Other packing container symbols include "T1B" and "T2B", which are used for tape packing containers. Any packing container symbol is always included in the part number for ordering.
The RF & microwave products are not packed in a magazine packing container, but in tape packaging container with each tape containing 50 products.

(2007/04)

Q-4

What does the (0) affixed to some transistor or FET order numbers mean?

A-4

(0) is an automotive electronics compliance symbol and means that the product is a high-quality, high-reliability product suitable for automotive applications.

(2006/07)

Q-5

How is the specification for automotive electronics in discrete products different from one for general-purpose?

A-5

The automotive specification product has higher quality and reliability than the general-purpose product because the reliability standards for automotive products, in addition to those for general-purpose products, are specifically defined so that the management of the production facilities and processes is stricter than for general-purpose.

(2008/02)

Q-1

Please explain the package markings.

A-1

The marking generally includes the NEC logo, the part number, the rank (when there are different ranks), and the lot number. Note, however, that due to space limitations, some of the above may be abbreviated, or indicated as symbols. The marking method may also differ depending on the package (i.e., numerals or binary dots for the lot number).

	Transistor (Bipolar, FET)	Zener Diode Note 2	Thyristor/TRIAC
Surface-mount type	Part number (symbol; based on hFE classification in the case of bipolar products Note 1) Lot number (numerals or dots)	Part number (abbreviated) Rank (some RD products: numerals (1, etc.) or dots) Cathode mark (2-pin products only)	Part number (symbol (SOT-89) or abbreviated (MP-3Z)) Rank (P), lot number (numerals)
Through-hole type	NEC logo (power types only) Part number: symbol ("2S" abbreviated) Rank (based on hFE), lot number (numerals)	Part number (abbreviated) Rank (B1, etc.) Cathode mark	NEC logo Part number (abbreviated) Rank (P), lot number (numerals)

Notes 1.	Example in the case of 2SC1623 Marked part number L4 L5 L6 L7 hFE 90 to 180 135 to 270 200 to 400 300 to 600 The marked part number on surface-mount transistors is described in the data sheet.
2.	Through-hole products are housed in glass packages.

How the rank and lot number are marked on through-hole package transistors and thyristors/TRIACs is shown below.



Control code definitions are not open to the public.
There is no control code indication on surface-mount packages.

The marking on Zener diodes and thyristors/TRIACs differs depending on the product. See their respective FAQ sections for details.

(2009/02)

Q-1

What is the meaning of the term "infinite heat sink" that appears on the total power dissipation vs. ambient temperature graph in power transistor and power MOS FET documentation?

A-1

This is assumed to mean "infinite heat sink ≈ Tc = 25°C". In other words, the case temperature must be kept to 25°C by attaching an extremely large heat radiator and externally dissipating the heat at the junction.

(2006/03)

Q-2

Two conditions are described for the total dissipation parameter in the power ratings of a power transistor or a power MOS FET: T_A = 25°C and T_C = 25°C. What is the difference between these conditions?

A-2

The specification at T_A = 25°C in the power ratings refers to the total power dissipation of a discrete semiconductor element in an environment with an ambient temperature of 25°C.
In this case, the thermal resistance from the heat source to the ambient air is expressed as R_th(j-a).

The specification at T_C = 25°C in the power ratings refers to the total power dissipation when the semiconductor element (case) itself has been forcibly cooled, i.e., when temperature of the package surface is kept at 25°C.
Note that the ratings may include the note "with infinite heat sink". However, in actual use, it is very difficult to make the package surface temperature exactly 25°C, and if you also take derating into account, the allowable power will in fact be somewhere in between T_A = 25°C and T_C = 25°C.

Related FAQ items
Thermal Design

(2006/07)

Q-3

The condition described in the absolute maximum rated total power dissipation for SC-62 products says when mounted on ceramic substrate, but what exactly is a ceramic substrate?

A-3

A ceramic substrate is formed by shaping a material such as ceramic in the form of a plate and then firing it to harden it. Since ceramic substrates offer excellent heat dispersion characteristics compared to glass epoxy substrates, they are often used for comparatively large-power ICs such as hybrid ICs.

(2006/12)

Q-4

The 2SD1000 (SC-62) is specified as having total power dissipation of 2 W when mounted on a ceramic substrate, but what is the total power dissipation when it is mounted on a glass epoxy substrate?

A-4

The total power dissipation of 2 W when the 2SD1000 (SC-62 package) is mounted on a ceramic substrate has been obtained from a thermal resistance between the junction and ambient of 62.5°C/W.
Since the thermal resistance between the junction and ambient is 150°C/W when the 2SD1000 is mounted on a glass epoxy substrate, calculation based on this figure gives [W = (150°C - 25°C)/150°C/W], resulting in 0.8 W at ambient 25°C.
Regarding the total power dissipation-ambient temperature characteristics, refer to the PT-TA graph in the data sheet taking into consideration the line connecting 25°C = 0.8 W and 150°C = 0 W in the PT-TA graph.

(2006/10)

Q-1

What items do I need to confirm when selecting a transistor or MOS FET?

A-1

You should confirm at least the following items.

Rating of VCEO and VDSS	→	Power supply voltage + margin
Rating of IC and ID	→	Load current + margin
Package	→	Size and mounting method
Rating of PT	→	Maximum ambient temperature during use
hFE and gate operating voltage	→	hFE and gate operating voltage according to circuit design
VCE(sat),RDS(on)	→	Effect of power consumption
NF,Ga,fT	→	Effect of high-frequency characteristics

(2007/04)

Q-1

The surface-mount packages of the TO-220 include the TO-220SMD (MP-25Z) and TO-263 (MP-25K, MP-25ZP). How do these packages differ?

A-1

The TO-263 (MP-25K, MP-25ZP) and the TO-220SMD (MP-25Z) do not differ greatly in terms of appearance.
However, the MP-25ZP guarantees operation on a large current (110 A).

The TO-220SMD (MP-25Z) is a JEITA (Japan Electronics and Information Technology Industries Association) standard package for use within Japan.

The TO-263 (MP-25K, MP-25ZP) is a JEDEC (Joint Electron Device Engineering Council) standard package.

(2006/04)

Q-2

Some of the old transistors include green mold resin.
Did green mold resin actually exist in the past products manufactured by you?

A-2

Green mold resin was used for PNP type transistors until December 1994. From January 1995, this has been replaced by black resin for all transistors.
Therefore, green mold resin exists in PNP type transistor lots up to December 1994.

(2006/11)

Q-1

The data sheet does not include a description of the thermal resistance.
How can I calculate it?

A-1

The thermal resistance can be calculated based on the total dissipation (PT) described in the data sheet.

• Junction-to-ambient Rth (j-a) = (Tj-Ta)/PT
• Junction-to-case Rth (j-c) = (Tj-Tc)/PT

Taking the 2SD1588 as an example, the thermal resistance is as follows.

• Rth (j-a) = (150°C - 25°C )/2W = 62.5°C/W
• Rth (j-c) = (150°C - 25°C)/30W = 4.17°C/W

Q-2

What is the junction-case thermal resistance of the SC-59 (minimold) and SC-62 (power minimold) packages?

A-2

The junction-case thermal resistance of neither package is specified (there is no specification for the total dissipation at Tc = 25°C).
Please use the following "Total Power Dissipation vs. Ambient Temperature" characteristics graph, which is included in the products' data sheets, to determine whether the product can be used in your application.



Click here to see the Total Power Dissipation vs. Ambient Temperature (T_A) characteristics graph when mounting the SC-62 on a glass epoxy board.

(2008/07)

Q-1

A distributor has notified us that we should avoid using the 2SC945A in new designs, even though it has not been discontinued.
Are there any replacement products that are not planned to be discontinued?

A-1

Small-signal type THD products, including the 2SC945A, are in the process of being phased out. We recommend that they not be used in new designs.
As replacements, we recommend that you consider surface-mount type products such as the 2SC1623 or 2SC4177.

(2007/09)

Q-1

The FAQ has the following about the operating temperature range: "Use with derating so that the junction temperature does not exceed 150°C." What exactly should be done for this derating?

A-1

When a case temperature is 100°C in the example shown in the figure, in order to operate in the safe operating range, the power consumption must be limited to less than 40% of that at 25°C. Derating refers to lowering the usage conditions, taking into consideration the ambient temperature around elements and the rise in temperature generated by the elements themselves.
In the case of use in the area above 40% in the figure, the junction temperature exceeds the absolute maximum rating of 150°C.

(2007/10)

Q-2

At what temperature must the case temperature of the 2SC4553 be maintained to prevent the junction temperature from exceeding 150°C at an ambient temperature of 55°C?

A-2

The thermal resistance between the junction and case is used to estimate the junction temperature from a measured case temperature.
The thermal resistance between the junction and case of the 2SC4553 is 4.2°C/W.
For example, the temperature difference between the junction and the case when the 2SC4553 is used at a total power dissipation of 10 W is 4.2°C × 10 W = 42°C as the thermal resistance between the junction and case = 4.2°C/W.
This means that the case temperature must be 150°C - 42°C = 108°C or less because the temperature difference between the junction and case is 42°C when the transistor is used at 10 W.
The junction temperature is therefore not directly related to the ambient temperature because it is estimated by measuring the case temperature. If the ambient temperature rises, however, the case temperature rises accordingly. Thus, the total power dissipation must be decreased so that the junction temperature does not exceed 150°C.

Related item: Thermal design

(2008/02)

Q-1

Which part of the power FET case should I measure temperature on, when doing the case temperature of a power FET that has a fin?

A-1

The easiest way is to measure the temperature by attaching a thermocouple on the interface between the fin and the resin close to the chip.

Q-1

What do the symbols of the absolute maximum ratings of transistors and FETs represent?

A-1

The symbols mean the following.
In V_(1)(2)(3), the symbols stand for the following:

(1)	Pin to be measured
(2)	Reference pin
(3)	Status of connection between the reference pin of (2) and a pin other than the pin of (1) or (2) S: Short O: Open X: Applied specified bias R: Connected to specified DC resistance

(2008/02)