Circular Connectors

Part Number	Description / PDF	Quantity
PD-40S CUI Devices	CONN JACK FMALE 4POS TIN SOLDER	12907
MD-80SV CUI Devices	CONN RCPT FMALE MINI DIN 8P SLDR	6529
SD-70LP CUI Devices	CONN PLUG MALE DIN 7P SOLDER	316
SD-50LS CUI Devices	CONN RCPT FMALE DIN 5P SOLDER	53
MD-80PL100 CUI Devices	CONN RCPT FMALE MINI DIN 8P WIRE	2277
SD-40SN CUI Devices	CONN RCPT FMALE DIN 4POS SOLDER	2025
MD-70 CUI Devices	CONN PLUG MALE MINI DIN 7P SLDR	334
SD-40J CUI Devices	CONN RCPT FMALE DIN 4P SOLDER	1525
MD-70SM CUI Devices	CONN RCPT FMALE MINI DIN 7P SLDR	4564
MD-80SMK CUI Devices	CONN RCPT FMALE MINI DIN 8P SLDR	6752
MD-80SP CUI Devices	CONN RCPT FMALE MINI DIN 8P SLDR	0
SD-60SN CUI Devices	CONN RCPT FMALE DIN 6P SOLDER	174
MD2-40ST-SMT CUI Devices	CONN RCPT FMALE MINI DIN 4P SLDR	1111
PDP-40 CUI Devices	CONN PLUG MALE 4 SILVER SOLDER	3536
SD-60J CUI Devices	CONN RCPT FMALE DIN 6P SOLDER	651
PD-30 CUI Devices	CONN JACK FMALE 3POS TIN SOLDER	58294
MD-40S CUI Devices	CONN RCPT FMALE MINI DIN 4P SLDR	1360
MD-70SP CUI Devices	CONN RCPT FMALE MINI DIN 7P SLDR	591
MD-50SN CUI Devices	CONN RCPT FMALE MINI DIN 5P SLDR	0
MD-70S CUI Devices	CONN RCPT FMALE MINI DIN 7P SLDR	1719

Circular Connectors

1. Overview

Circular connectors are multi-pin electrical connectors with circular contact arrangements, designed for reliable signal/power transmission in harsh environments. They feature robust mechanical structures, environmental sealing, and high mating durability. These connectors are critical in aerospace, industrial automation, and medical equipment where vibration resistance and signal integrity are paramount.

2. Main Types & Functional Classification

Type	Functional Characteristics	Application Examples
MIL-DTL-38999	High-density, threaded coupling, EMI shielding	Aerospace systems, military vehicles
USB Type-C	Reversible design, 10Gbps data rate, 100W power delivery	Smartphones, laptops, PDAs
BNC	Bayonet locking, 2GHz frequency range	Test equipment, video systems
LVDT Circular	Linear variable differential transformer integration	Industrial sensors, robotics

3. Structure & Components

Typical construction includes: - Shell: Aluminum alloy/zinc die-cast housing with corrosion-resistant plating - Contacts: Gold-plated phosphor bronze with 0.5-2.0mm diameter - Insulation: High-temperature thermoplastic (200 C rating) - Sealing: IP67/IP68 rated elastomer gaskets - Mounting: Threaded/flange/clamp mechanisms

4. Key Technical Parameters

Parameter	Typical Range	Importance
Voltage Rating	50V-600V	Determines power transmission capacity
Current Rating	1A-25A/contact	Affects thermal performance
Contact Resistance	5m	Impacts signal integrity
IP Rating	IP40-IP68	Defines environmental protection level
Operating Temp	-65 C to +200 C	Material stability indicator
Mating Cycles	500-10,000	Service life predictor

5. Application Fields

Aerospace: Flight control systems, satellite antennas
Industrial: CNC machines, automated guided vehicles
Medical: MRI scanners, patient monitoring systems
Telecom: 5G base stations, fiber optic networks
Consumer: VR headsets, gaming peripherals

6. Leading Manufacturers

Manufacturer	Key Products	Special Features
Amphenol	MIL-DTL-38999 series	Composite materials, EMI filtering
TE Connectivity	DEUTSCH D38999	Thermoplastic housing, 2000V dielectric
Molex	USB Type-C 10Gbps	Shielded twinax design
Delphi	Automotive circular connectors	IP69K rating for EV charging
Lemo	Push-pull circular series	Subminiature, 5000+ mating cycles

7. Selection Guidelines

Key considerations: 1. Environmental factors: Temperature extremes, fluid exposure 2. Electrical requirements: Signal type (analog/digital), current load 3. Mechanical constraints: Panel space, mating force limitations 4. Compliance standards: MIL-STD, ISO 6722, RoHS 5. Cost vs. longevity: High-cycle applications justify premium connectors

8. Industry Trends

Emerging developments include: - Miniaturization: 1.0mm contact pitch enabling wearable devices - High-speed transmission: 25Gbps+ differential pairs for industrial IoT - Smart connectors: Integrated sensors for condition monitoring - Material innovation: Graphene-coated contacts reducing resistance - Eco-design: Halogen-free thermoplastics meeting REACH regulations