Terminal Blocks - Headers, Plugs and Sockets

Part Number	Description / PDF	Quantity
691701310004B Würth Elektronik Midcom	3.81 MM TERMINAL BLOCK HEADER, V	834
691323100005 Würth Elektronik Midcom	3.50 MM TERMINAL BLOCK HEADER, V	639
691361300023 Würth Elektronik Midcom	TERM BLOCK PLUG 23POS 3.81MM	40
691368300014B Würth Elektronik Midcom	TERM BLOCK PLUG 14POS STR 3.81MM	0
691352510012 Würth Elektronik Midcom	TERM BLOCK PLUG 12POS 5.08MM	24
691365310012 Würth Elektronik Midcom	3.81 MM TERMINAL BLOCK PLUG, HOR	89
691351700004 Würth Elektronik Midcom	TERM BLOCK PLUG 4POS 5MM	661
691374500011B Würth Elektronik Midcom	TERM BLOCK PLUG 11POS STR 5.08MM	0
691701520008B Würth Elektronik Midcom	5.08 MM TERMINAL BLOCK HEADER, V	299
691312510020 Würth Elektronik Midcom	TERM BLOCK HDR 20P 90DEG 5.08MM	59
691338500004 Würth Elektronik Midcom	5.08 MM TERMINAL BLOCK HEADER, D	300
691305530005 Würth Elektronik Midcom	WR-TBL SERIES 3055_5.08 MM_PCB H	515
691307400006 Würth Elektronik Midcom	7.62 MM TERMINAL BLOCK HEADER, V	240
691323300008 Würth Elektronik Midcom	3.81 MM TERMINAL BLOCK HEADER, V	617
691323300012 Würth Elektronik Midcom	3.81 MM TERMINAL BLOCK HEADER, V	169
691334500020 Würth Elektronik Midcom	5.08 MM TERMINAL BLOCK HEADER, D	20
691329300010 Würth Elektronik Midcom	3.81 MM TERMINAL BLOCK HEADER, D	139
691353500013 Würth Elektronik Midcom	5.08 MM TERMINAL BLOCK PLUG, VER	20
691345410002 Würth Elektronik Midcom	7.62 MM TERMINAL BLOCK PLUG, HOR	288
691319510012 Würth Elektronik Midcom	5.08 MM TERMINAL BLOCK HEADER, D	40

Terminal Blocks - Headers, Plugs and Sockets

1. Overview

Terminal blocks, headers, plugs, and sockets are essential components in electrical and electronic systems for establishing reliable connections between circuits. These devices enable signal transmission, power distribution, and system modularity. Their standardized designs ensure interoperability, scalability, and ease of maintenance in complex systems.

2. Main Types and Functional Classification

Type	Functional Characteristics	Application Examples
Terminal Blocks	Screw/clamp-based connections for high current/ voltage	Industrial control panels, power distribution units
PCB Headers	Pin/grid arrays for board-to-board connections	Embedded systems, Arduino shields
RJ Connectors	Modular jacks for data/telecom signals	Ethernet networks (RJ45), telephone systems (RJ11)
D-Sub Connectors	Multi-pin trapezoidal shells for analog/digital signals	Legacy serial interfaces, industrial sensors
USB Connectors	Hot-pluggable interfaces for power/data	Consumer electronics, peripheral devices

3. Structure and Components

Typical structures include:

Insulating housing (PA66, PBT, or LCP plastics)
Contact elements (phosphor bronze, beryllium copper)
Plating materials (gold, tin, nickel for corrosion resistance)
Actuation mechanisms (screws, spring clamps, or friction fits)
EMI shielding layers (for high-frequency applications)

4. Key Technical Specifications

Parameter	Importance
Current Rating (A)	Determines power handling capacity
Voltage Rating (V)	Defines dielectric strength requirements
Contact Resistance (m )	Impacts signal integrity and power loss
Insertion Loss (dB)	Critical for high-speed data transmission
Mating Cycles	Indicates mechanical durability
Operating Temperature (- C to + C)	Defines environmental tolerance

5. Application Fields

Primary industries include:

Industrial automation (PLCs, HMIs)
Telecommunications (5G base stations, routers)
Consumer electronics (smartphones, wearables)
Medical equipment (imaging devices, patient monitors)
Automotive (EV charging systems, ADAS)

6. Leading Manufacturers and Products

Manufacturer	Representative Product
Phoenix Contact	COMBICON series terminal blocks
TE Connectivity	MICRO MATCH connectors
Molex	SL Series headers
Amphenol	D-Subminiature connectors
Samtec	QTE high-speed socket systems

7. Selection Guidelines

Key considerations:

Electrical requirements (current/voltage levels)
Mechanical constraints (space, vibration)
Environmental factors (temperature, humidity)
Signal integrity needs (frequency, noise rejection)
Cost vs. reliability trade-offs
Compliance with standards (IPC, IEC, UL)

8. Industry Trends

Emerging developments include:

Miniaturization for wearable devices
High-speed connectors for 5G/6G ( 25 Gbps)
Hybrid connectors integrating power/data
Eco-friendly materials (halogen-free, RoHS compliant)
Smart connectors with built-in sensors
Automotive-grade connectors for EVs