Connector Selection Guide

1. Connector Family Definition

The connectors used on our products are third-party compatible parts. Their mechanical interface is commonly described as a 1.25 mm PicoBlade-compatible wire-to-board connector.

2. Correct Component Names

3. Cable-Side Connector Selection Table

The cable-side housing must have the same circuit count as the PCB header. For example, a product fitted with a 7-circuit PCB header requires a 7-circuit receptacle housing containing seven matching female crimp terminals.

* The 51021 series numbers are provided only as mechanical cross-references to help identify the connector interface. They do not mean that our products use genuine Molex housings. Third-party compatible parts may differ from Molex parts in material, plating, tolerances, electrical performance, mating force, and service life.

4. Terminal and Wire Selection

4.1 Matching Crimp Terminals

Use female crimp terminals specifically designed for the selected 1.25 mm PicoBlade-compatible receptacle housing. Common Molex PicoBlade terminal families used as cross-references include:

• 50079 series: typically used with approximately 26–28 AWG wire;
• 50058 series: typically used with approximately 28–32 AWG wire.

4.2 Recommended Wire Size

For typical signal wiring, 28 AWG is generally a practical starting point. The final wire size must still be selected according to current, wire length, voltage drop, flexibility, insulation diameter, and the crimp range specified by the terminal supplier.

5. Standard Purchasing Descriptions

Standard Full Description

Short Purchasing Description

Recommended Search Terms

Replace “__” with the required circuit count, such as 4, 7, 8, 10, 11, or 12.

6. Where to Buy in the United States and Europe

Compatible cable assemblies and connector kits are commonly available through general electronics marketplaces and specialist cable suppliers. The exact brand of the compatible connector is not important, provided that the mechanical interface, pitch, circuit count, and mating direction are verified.

7. Recommended Search Keywords

The most effective general search phrase is:

Add the circuit count and cable format to narrow the result. For example:

7.1 Single-Ended Pigtail Cable

Use these terms when one end has the connector and the other end has loose wires:

7.2 Double-Ended Cable Assembly

Use these terms when both ends use the same mating connector:

7.3 Housing with Pre-Crimped Wires

Use these terms when the terminals are already crimped to the wires but still need to be inserted into the housing:

7.4 Empty Receptacle Housing

7.5 Housing with Loose Crimp Terminals

7.6 PCB Header

Replace “7”, “7P”, or “0700” with the required circuit count and matching reference number.

8. Direct Search Terms for 4P–12P

The following terms can be copied directly when searching for single-ended pigtail cables:

For empty housings, replace pigtail cable with:

For housings supplied with loose terminals, replace it with:

9. Search Terms to Avoid

Products described only as GH1.25 or JST GH 1.25 mm should not be assumed to fit. JST GH uses a different locking and housing geometry and is generally not interchangeable with the PicoBlade-compatible interface.

The preferred search pattern for all products is:

Example for an 11-circuit single-ended cable:

10. Customer-Facing Purchase Instruction

11. Purchasing and Incoming Inspection Checklist

• Confirm the circuit count: 4P through 12P housings are not interchangeable.
• Confirm the pitch: The nominal pitch is 1.25 mm, but pitch alone does not establish compatibility.
• Check the locking geometry: The guide rails, friction lock, and insertion depth must match the PCB header.
• Confirm orientation: Identify Pin 1 using the PCB marking or product wiring diagram.
• Use matched components: Prefer housings, terminals, and crimp specifications from the same supplier.
• Test samples first: Verify mating, retention, continuity, polarity, and contact stability before mass production.
• Inspect the crimp: Both conductor and insulation crimps must be complete and properly formed.
• Do not force insertion: Excessive mating force indicates a possible series, orientation, or terminal-position mismatch.

12. Similar Connector Families That Are Not Interchangeable

Many miniature connector families use nominal pitches between approximately 1.0 mm and 1.5 mm. Even when the pitch and circuit count appear identical, the housing dimensions, latch geometry, terminal position, and mating depth may be different.

13. Recommended Selection Procedure

1. Check the product specification, PCB marking, or wiring diagram to identify the required circuit count.
2. Select a 1.25 mm PicoBlade-compatible receptacle housing with the same circuit count.
3. Select matching female crimp terminals suitable for the intended wire size.
4. Confirm wire colors, cable length, Pin 1 orientation, and the complete pin assignment.
5. Purchase a small sample quantity and complete mating and electrical tests before mass production.

14. Reference Resources