Circular Connectors

Part Number	Description / PDF	Quantity
SD-50BV CUI Devices	CONN RCPT FMALE DIN 5POS SOLDER	1635
PD-40V CUI Devices	CONN RCPT FMALE 4 SILVER SOLDER	2083
SD-130 CUI Devices	CONN PLUG MALE DIN 13P SOLDER	1962
MD-50FC CUI Devices	CONN JACK FMALE MINI DIN 5P SLDR	4250
MD-30SMK CUI Devices	CONN RCPT FMALE MINI DIN 3P SLDR	898
MD-60SN CUI Devices	CONN RCPT FMALE MINI DIN 6P SLDR	1024
MD-50 CUI Devices	CONN PLUG MALE MINI DIN 5P SLDR	2733
SD-70BV CUI Devices	CONN RCPT FMALE DIN 7POS SOLDER	268
SD-50 CUI Devices	CONN PLUG MALE DIN 5P SOLDER CUP	4182
SDS-30J CUI Devices	CONN RCPT FMALE DIN 3POS SOLDER	789
MD-30SN CUI Devices	CONN RCPT FMALE MINI DIN 3P SLDR	622
PD-40VS CUI Devices	CONN RCPT FMALE 4 SILVER SOLDER	7413
MD-30CV CUI Devices	CONN RCPT FMALE MINI DIN 3P SLDR	196
MD-80FC CUI Devices	CONN JACK FMALE MINI DIN 8P SLDR	3130
MD-60S CUI Devices	CONN RCPT FMALE MINI DIN 6P SLDR	11992
MD-40SM CUI Devices	CONN RCPT FMALE MINI DIN 4P SLDR	14064
MD-70J CUI Devices	CONN RCPT FMALE MINI DIN 7P SLDR	439
SD-30 CUI Devices	CONN PLUG MALE DIN 3P SOLDER CUP	2613
MD-80 CUI Devices	CONN PLUG MALE MINI DIN 8P SLDR	6941
SDF-50J CUI Devices	CONN RCPT FMALE DIN 5POS SOLDER	9311

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