JST Connector (2-pin) Symbol
Definition: The JST Connector (2-pin) symbol represents a 2-pole miniature wire-to-board or wire-to-wire connector from JST's PH, XH, or SH series in circuit diagrams, drawn as a labeled connector block with pins + (positive) and − (negative), used for low-voltage power connections including LiPo battery packs, per IEC 60617 general connector conventions and ANSI Y32.2 / IEEE 315.
Also known as: JST 2-pin, JST PH 2.0mm connector, LiPo battery connector, JST plug, JST battery lead, 2-pin JST socket.
What the JST Connector (2-pin) symbol means
The JST Connector (2-pin) symbol denotes a two-circuit miniature plastic housing connector manufactured to JST (Japan Solderless Terminal) dimensional standards. In schematic diagrams it marks a removable, polarised power connection point, most commonly used to connect lithium polymer (LiPo) battery packs to circuit boards in RC vehicles, drones, wearables, and portable electronics.
The two pins are designated + (positive supply) and − (negative/ground). The connector housing is keyed to prevent reverse insertion, and the small 1.25–2.54 mm pitch makes it ideal for compact PCB designs. In wiring diagrams the JST 2-pin symbol signals a safe, user-serviceable disconnect point in a low-voltage power circuit.
How to identify the JST Connector (2-pin) symbol
The JST Connector (2-pin) symbol is drawn as a small rectangular block labeled 'JST' or 'JST 2-pin' with two pins emerging from one edge: the + pin (positive) and the − pin (negative). Some schematic representations show the connector as two parallel vertical lines with connecting tabs, similar to a multi-pin header symbol. The small pitch dimension (1.25 mm, 2.0 mm, or 2.54 mm) is often annotated to distinguish between JST series.
Function in a circuit
The JST 2-pin connector provides a mechanically and electrically reliable removable connection between two conductors, typically carrying DC power from a battery or power supply to a load circuit. The polarised housing prevents reverse connection. Crimped contacts provide low resistance and vibration resistance superior to friction-fit connectors, making the JST 2-pin suitable for mobile and handheld applications where repeated connection and disconnection cycles are expected.
Standards: IEC vs ANSI
| IEC 60617 | IEC 60603 series governs miniature connectors in general; JST connectors additionally follow JST's own proprietary dimensional specifications. IEC 60617 general connector symbol conventions apply for schematic representation. |
|---|---|
| ANSI/IEEE 315 | ANSI Y32.2-1975 / IEEE 315-1975 use a labeled block or multi-pin symbol for connectors; JST physical dimensions follow JST's proprietary standards rather than a public ANSI document. |
| Key difference | IEC and ANSI schematics both represent the JST 2-pin connector as a labeled two-pin connector block. The physical connector is defined by JST's proprietary series specifications (PH = 2.0 mm pitch, XH = 2.5 mm pitch, SH = 1.0 mm pitch) rather than a published IEC or ANSI standard. |
Terminals / pins
| Pin | Name |
|---|---|
| p1 | + |
| p2 | - |
Typical values
Pitch: 1.0 mm (SH), 1.25 mm (GH/ZH), 2.0 mm (PH), 2.5 mm (XH), 2.54 mm (VH). Current rating: 1 A (SH/GH) to 3 A (VH) per contact. Voltage rating: 50–250 V AC/DC depending on series. Contact resistance: <20 mΩ. Insulation resistance: >100 MΩ. Operating temperature: −25 °C to +85 °C.
Where the JST Connector (2-pin) symbol is used
- LiPo battery pack connections in RC aircraft, drones, and FPV racers (JST PH 2.0 mm is near-universal for small LiPo cells)
- Wearable electronics and smartwatch battery connections (JST SH 1.0 mm)
- Arduino and microcontroller project power input and sensor connections
- Drone and robot internal wiring for motor controllers and peripherals
- Consumer electronics where a user-replaceable battery or modular accessory is needed
- LED strip lighting 12 V power feeds where plug-in serviceability is required
Example
In a drone flight-controller schematic, the JST Connector (2-pin) symbol shows the + pin connecting to the positive battery bus (3.7 V nominal for 1S LiPo) and the − pin connecting to the power ground plane. A reverse-polarity protection PMOS transistor immediately downstream of the connector protects the ESCs and flight controller from accidental battery reversal.
Key facts
- The JST Connector (2-pin) symbol represents a 2-pole miniature polarised connector with pins designated + (positive) and − (negative), standardised dimensionally by JST Co. Ltd. in series such as PH (2.0 mm pitch) and SH (1.0 mm pitch).
- JST connectors are polarised by an asymmetric housing key that physically prevents reverse insertion, protecting circuits from reversed polarity.
- Current ratings range from 1 A per contact (SH series, 1.0 mm pitch) to 3 A per contact (VH series, 3.96 mm pitch); the 2-pin JST PH at 2.0 mm pitch is rated 2 A.
- The JST PH 2.0 mm 2-pin connector is the de facto standard battery connector for small LiPo cells used in RC aircraft, drones, and portable electronics worldwide.
- Contact crimping provides lower and more consistent contact resistance than insulation-displacement or friction-fit connections, with contact resistance typically under 20 mΩ.
- IEC 60617 and ANSI Y32.2 / IEEE 315 represent the JST 2-pin connector as a general labeled multi-pin connector block; no dedicated JST glyph is defined in either standard.
- The mating plug and socket pair share the same series name and pitch; plugging a JST PH plug into an XH socket is physically prevented by the different pitch and housing dimensions.
Frequently asked questions
What does the JST Connector (2-pin) symbol mean in a circuit diagram?
The JST Connector (2-pin) symbol represents a two-circuit miniature polarised connector used for removable power connections, most commonly for LiPo battery packs. The + pin carries positive supply voltage and the − pin carries ground, with the keyed housing preventing reverse insertion.
What does the JST 2-pin symbol look like on a schematic?
The JST 2-pin symbol appears as a small labeled rectangular block with two pins: + (positive) on one position and − (negative) on the other. It is drawn similarly to a 2-pin header symbol, typically annotated with 'JST' and the series pitch (e.g., '2.0 mm PH') to distinguish it from other connector types.
What is the most common JST 2-pin connector series?
The JST PH series at 2.0 mm pitch is the most widely used 2-pin JST connector for LiPo battery packs in RC aircraft, drones, and small electronics. The JST SH series at 1.0 mm pitch is standard for wearable and compact devices, and the JST XH series at 2.5 mm pitch is common in larger 3S and 4S drone batteries.
Are JST connectors polarised?
Yes. JST connectors are mechanically polarised by an asymmetric housing with a tab or key on one side that only allows insertion in the correct orientation. This prevents reverse-polarity connection that could damage circuits or cause LiPo batteries to discharge dangerously. The + and − pin assignment is fixed by the housing orientation.
What standard defines JST connectors?
JST connectors are specified by JST Co. Ltd.'s own proprietary dimensional standards for each series (PH, XH, SH, GH, etc.). IEC 60603 series covers miniature connectors in general principle, and IEC 60617 / ANSI Y32.2 govern schematic symbol conventions, but the specific JST series dimensions are defined by JST's manufacturer datasheets.
What current can a JST 2-pin connector carry?
Current capacity depends on the JST series: JST SH (1.0 mm pitch) is rated 1 A per contact; JST PH (2.0 mm pitch) is rated 2 A per contact; JST XH (2.5 mm pitch) is rated 3 A per contact. For a 2-pin connector carrying single-circuit power, the current limit equals the single-contact rating of that series.
What is the designator for a JST connector in a schematic?
The reference designator for a connector, including a JST 2-pin connector, is J (jack/socket) or P (plug) per IEC 60617 and ANSI Y32.2 / IEEE 315, e.g., J1 for the board-mounted socket and P1 for the mating cable plug. Connectors are numbered sequentially in the schematic.
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