on October 30th 5,350

SOT23 and SOT323: What’s the Difference?

The Small Outline Transistor (SOT) package family is a cornerstone of compact and efficient electronic design, mostly through surface-mount technology (SMT). Found in smartphones, laptops, and other high-density devices, SOT packages like SOT23 and its slimmer variant, TSOT, enable you to achieve optimal space utilization. The subtle differences between these packages—such as height and footprint—play an active role in modern circuitry, impacting decisions around layout, heat management, and component density. Understanding these variations is basic for selecting the right package based on device-specific needs and performance goals.

Catalog

Comparison of SOT23 and SOT323

SOT23 and SOT323 packages are basic in housing surface-mounted transistors in electronic devices. SOT23 features three terminals. The lead pitch is 1.9mm. The body dimensions are 2.9mm x 1.33mm x 1mm. SOT323 also has three terminals. The lead pitch is 1.3mm. Dimensions are 2mm x 1.25mm x 0.95mm.

A variety of considerations influence the decision to use either SOT23 or SOT323. SOT23 is often favored in scenarios where slightly larger board space is flexible. Conversely, the SOT323, with its reduced size, proves advantageous in designs where every millimeter counts, emphasizing thoughtful PCB layout planning to enhance efficiency in tightly packed electronics.

In electronics, the selection of packages shapes the design and performance of products. SOT23 offers more ease in manual soldering due to its wider pitch, while SOT323 shines in automated assembly settings where conserving space and minimizing weight take precedence.

Pin Configuration

Differences in Features

Feature	SOT-23	SOT-323
Application	CAN-Bus and interface ESD protection	CAN-Bus and interface ESD protection
Package Type	SOT-23	SOT-323
Package Height	1.2 mm	1.1 mm
AEC-Q101 Qualified Versions	Available	Available
Working Range	VCAN16A2: ±16V / VCAN33A2: ±33V	VCAN16A2: ±16V / VCAN33A2: ±33V
Leakage Current	<0.05 μA	<0.05 μA
Load Capacitance (CD)	VCAN16A2: <18.5 pF / VCAN33A2: <9.7 pF	VCAN16A2: <18.5 pF / VCAN33A2: <9.7 pF
ESD Protection (IEC 61000-4-2)	±30 kV (contact and air discharge)	±30 kV (contact and air discharge)
Soldering Inspection	AOI (Automated Optical Inspection)	AOI (Automated Optical Inspection)
Pin Plating	Tin (Sn)	Tin (Sn)

Parameter Variations in SOT23 and SOT323

The SOT23 and SOT323 packages exhibit notable distinctions in size, especially in pitch and length. The SOT23's 'G' length measures 1.9mm, contrasting with the 1.3mm of the SOT323. Similarly, the 'L' length is 0.95mm for SOT23, whereas it is 0.65mm for SOT323. These differences profoundly influence component layout and space efficiency on circuit boards.

When choosing components, verifying dimensions against application-specific requirements is a thoughtful practice. You can often deliberate over the constraints posed by circuit board space and the compatibility of assembly processes. SOT323's smaller size might appeal to designs aiming for high-density component arrangements or more compact structures.

Package Dimensions of SOT323 and SOT23

SOT23 Package Design Insights

SOT23 Package Parameters

Symbol	Parameter	Min	Typ	Nom	Max	Unit
D	Package Length	2.8		2.9	3	mm
E	Package Width	1.2		1.3	1.4	mm
A	Seated Height	0.9		1	1.1	mm
e	Nominal Pitch	-	■	1.9	-	mm
ei	Minimal Pitch	-	-	-	-	mm
n2	Actual Quantity of Termination	-	■	3	-

SOT323 Package Design Insights

SOT23 Package Parameters

Symbol	Parameter	Min	Typ	Nom	Max	Unit
D	Package Length	1.8		2	2.2	mm
E	Package Width	1.15		1.25	1.35	mm
A	Seated Height	0.8		0.95	1.1	mm
e	Nominal Pitch	-	■	1.3	-	mm
n2	Actual Quantity of Termination	-	■	3	-

Soldering Distinctions in SOT23 and SOT323

Reflow Soldering

Wave Soldering

Conclusion

In selecting between SOT packages like SOT23 and SOT323, you must consider the intricate balance between size, thermal properties, and electronic performance. The smaller footprint of the SOT323 offers advantages in highly compact designs, though it may introduce challenges in thermal dissipation. Conversely, SOT23 can be beneficial for layouts requiring slightly more space and easier heat management. Thoughtful selection of SOT packages enhances component efficiency and system reliability, emphasizing the importance of dimension-aware design in achieving optimal performance in consumer electronics.

Frequently Asked Questions [FAQ]

1. What does SOT stand for?

SOT, or Small Outline Transistor, signifies a compact packaging technology within semiconductor devices that enhances efficiency in limited spaces.

2. What are SOT23 and SOT323?

SOT23 and SOT323 are plastic, surface-mounted packages prized for their adaptability. SOT23 is larger than SOT323, influencing thermal and electrical traits suited for specific circuit demands. You can often choose SOT23 when thermal management is paramount, as its size facilitates better heat dissipation.

3. How many terminals does SOT23 have?

The SOT23 package includes three terminals. This configuration aligns with functions like gate, source, and drain connections in transistors, aligning with diverse electronic applications. Such a layout offers an effective balance between functionality and compactness, required for modern device design.

4. How many terminals does SOT2 have?

The pitch of the SOT23 package measures 1.9mm. This dimension subtly influences the effective arrangement of printed circuit boards (PCBs). You can frequently prioritize the pitch for designing high-density systems, pursuing the best possible electrical performance. Accurate alignment minimizes parasitic inductance and capacitance, bolstering signal integrity. You can observe that careful attention to these parameters helps circumvent common issues such as signal interference or cross-talk, especially in intricate multi-layer configurations.

5. What is the difference between SOT323 and SOT23?

SOT323 is noted for its smaller size compared to SOT23, presenting substantial benefits in compact electronic designs where space is scarce. Though both packages retain reliability and efficiency, the decision often hinges on specific design limitations and application needs. You can recognize that finding the right balance between size, thermal, and electrical capabilities can significantly impact device reliability. Investigating these trade-offs uncovers richer insights into the complex design decisions that propel modern technological advancement.