Terminal Blocks - Headers, Plugs and Sockets

Part Number	Description / PDF	Quantity
691357300006B Würth Elektronik Midcom	3.81 MM TERMINAL BLOCK HEADER, D	160
691322310016 Würth Elektronik Midcom	3.81 MM TERMINAL BLOCK HEADER, H	148
691374500021B Würth Elektronik Midcom	TERM BLOCK PLUG 21POS STR 5.08MM	0
691340500005 Würth Elektronik Midcom	5.08 MM TERMINAL BLOCK PLUG, VER	208
691352710003 Würth Elektronik Midcom	TERM BLOCK PLUG 3POS 5MM	194
691365110003 Würth Elektronik Midcom	3.50 MM TERMINAL BLOCK PLUG, HOR	468
691321100005 Würth Elektronik Midcom	TERM BLOCK HDR 5POS VERT 3.5MM	1002
691351700006 Würth Elektronik Midcom	TERM BLOCK PLUG 6POS 5MM	91
691317510005 Würth Elektronik Midcom	5.08 MM TERMINAL BLOCK HEADER, H	244
691313710002 Würth Elektronik Midcom	TERM BLOCK HDR 2POS 90DEG 5MM	903
691335510004 Würth Elektronik Midcom	5.08 MM TERMINAL BLOCK HEADER, D	0
691322310008 Würth Elektronik Midcom	TERM BLOCK HDR 8POS 90DEG 3.81MM	53
691701520012B Würth Elektronik Midcom	5.08 MM TERMINAL BLOCK HEADER, V	150
691325110002 Würth Elektronik Midcom	3.50 MM TERMINAL BLOCK HEADER, H	683
691356300006B Würth Elektronik Midcom	3.81 MM TERMINAL BLOCK HEADER, D	204
691386700013 Würth Elektronik Midcom	5.00 MM TERMINAL BLOCK HEADER, H	49
691345510012 Würth Elektronik Midcom	5.08 MM TERMINAL BLOCK PLUG, HOR	40
691309510003 Würth Elektronik Midcom	5.08 MM TERMINAL BLOCK HEADER, H	393
691370710007B Würth Elektronik Midcom	5.00 MM TERMINAL BLOCK HEADER, H	100
691321300016 Würth Elektronik Midcom	3.81 MM TERMINAL BLOCK HEADER, V	500

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