Table of Contents
I/O connector (Input/Output Connector) is a physical interface between a computer or electronic device and external devices.
It transmits data, control signals, or power between a host computer (such as a CPU or motherboard) and external devices (such as hard drives, printers, and cameras).
Its core function is to enable data input and output, and it is the key hardware foundation for system scalability and functional diversity.
What are the types of IO connectors?
I/O connectors (input/output connectors) are the core hardware for data exchange between computer systems and external devices. They can be divided into the following categories based on their functional architecture, physical form, and application scenarios:
1. Classification by functional architecture
I/O Interface Chip
Function: Integrated circuit chip that controls peripheral operations through CPU instructions.
Typical Types:
- Timer (e.g., 8253): Manages time-related tasks.
- Interrupt Controller (e.g., 8259): Handles device interrupt requests.
- DMA Controller (e.g., 8237): Enables direct data transfer between memory and peripherals.
- Parallel Interface Chip (e.g., 8255): Supports multi-channel parallel signal transmission.
I/O Interface Controller Card
Function: A logic component consisting of multiple chips, plugged into a motherboard or bus slot.
Typical Types:
- Serial interface card (e.g., RS-232): Connects modems and industrial equipment.
- Parallel interface card (e.g., Centronics): Supports low-speed devices such as printers.
- Disk interface card (e.g., IDE): Parallel connection solution for early hard drives and optical drives.
2. Classification by physical form
System Connectors
Features: High density, supports differential signaling, and has speeds >2.5 Gb/s. Suitable for high-speed chip-to-chip interconnects (e.g., server backplanes).
Rectangular Connectors
Features: Multi-contact design, transmits mixed signals (data + power), and is used for connecting sensors/actuators in industrial automation equipment.
Circular Connectors
Features: Strong sealing and environmental impact resistance. Suitable for aerospace and military equipment (e.g., aircraft electronic systems).
Strip Connectors (Cable Connectors)
Features: Compact and high-density. Suitable for connecting motherboards to internal devices such as hard drives and optical drives (e.g., IDE cables).
Pluggable Connectors
Features: Modular design, hot-swappable support, suitable for high-speed network equipment:
SFP/SFP+: 1G~16Gbps (switch optical modules).
QSFP/QSFP28: 40G~100Gbps (data center high-speed interconnects). CFP: 100G~400Gbps (ultra-high-speed network transmission)
3. Classification by application field
Storage Device Interfaces
SATA: Serial hard drive interface, speed ≤ 6 Gbps.
NVMe: A high-speed interface dedicated to SSDs based on PCIe channels (speeds > 3.5 GB/s).
Network Interfaces
Ethernet (RJ45): A wired LAN standard (1G to 100G).
Fibre Channel Connectors: High-reliability data center networks (such as SFP28 optical modules).
Audio and Video Interfaces
HDMI: High-definition audio and video transmission (supports 4K/120Hz).
VGA: Analog video output (gradually phased out).
Universal Input/Output Device Interfaces
USB: Supports keyboards, mice, USB flash drives, etc. (speeds range from 1.5 Mbps to 20 Gbps).
Thunderbolt: A fusion of PCIe and DisplayPort, with speeds up to 40 Gbps.
4. High-speed dedicated connector
High-Speed Backplane Connectors
Types:
- Traditional Backplane: PCB trace connections (low cost, limited speed).
Orthogonal Zero Backplane: Direct connector interconnection (improves signal integrity, supports 112 Gbps).
Cable Backplane: Replaces PCBs with high-speed cables (long-distance, low-loss).
RF Connectors
Coaxial:
Fakra: Automotive antennas (6 GHz).
Mini-Fakra (HFM): 4K cameras/autonomous driving (28 Gbps).
Differential:
HSD: In-vehicle entertainment systems (6 Gbps).
Ethernet Connectors: Smart automotive sensor networks
5. Core function comparison
Summarize
The diversity of I/O connectors stems from the speed, reliability, and environmental adaptability requirements of various scenarios:
• Functional chip-level connectors (e.g., 8259) address underlying control issues;
• Physical form factors (e.g., circular/strip) accommodate mechanical and environmental constraints;
• Protocol-driven connectors (e.g., SFP+/USB) target high-speed data exchange. Modern systems are increasingly adopting modular pluggable designs (e.g., QSFP-DD), which balance flexibility with ultra-high bandwidth requirements and are gradually replacing traditional parallel interfaces (e.g., SCSI).