S2B-PH-K-S PCB Design Guide: Footprint, Pinout, and Alternatives
Two-pin, side-entry JST PH wire-to-board header on a 2.0 mm pitch
S2B-PH-K-S is JST's two-circuit, side-entry, through-hole header for the PH wire-to-board connector family. It mates with the PHR-2 cable housing, uses a 2.0 mm pin pitch, and puts the cable parallel to the PCB. The shroud and friction lock make it a better cable connector than a bare pin header when board space is tight.
The exact model code matters. S identifies side entry, 2 identifies two circuits, and K identifies clinched through-hole posts. The catalog rates the PH family at 2 A with AWG #24 wire and 100 V AC/DC, but the header, housing, and crimp contacts are ordered separately. Most board failures come from choosing a 2.54 mm footprint, mirroring JST's mounting-surface drawing, or assuming the 2 A family rating applies to every allowed wire gauge.
What breaks boards
The mating housing and contacts are separate parts
S2B-PH-K-S is only the PCB header. A two-position cable assembly also needs a PHR-2 housing and PH crimp contacts selected for the wire size. The catalog splits AWG #32 to #28 and AWG #30 to #24 across different standard contacts.
Use the side-entry footprint, viewed from the mounting surface
The S prefix identifies side entry. JST states that its PCB layout is viewed from the connector mounting surface. Mirroring that view or using the top-entry B2B footprint can reverse the finished cable orientation.
Two amps depends on AWG #24 and thermal conditions
The 2 A rating is stated for AWG #24 and includes connector temperature rise in the -40°C to +105°C range. Do not transfer 2 A blindly to AWG #28 or #32 wiring or to a hot enclosure.
The drill recommendation is not universal
JST calls its hole dimensions reference values and says the required hole can change with PCB material and drilling method. Confirm finished-hole size and plating with the board fabricator, especially on fiberglass-cloth laminate.
PH is 2.0 mm pitch, not the common 2.54 mm header grid
The pin pitch is 2.0 mm. A 0.1-inch library footprint will not fit, even though a two-pin rendering can look close on screen. Check the A = 2.0 mm and B = 5.9 mm dimensions against the footprint before ordering boards.
Key specifications
| Parameter | Value | Source |
|---|---|---|
| Connector identity | S2B-PH-K-S; 2-circuit side-entry through-hole PH header | JST PH catalog, Header (Through-hole type) table and model number allocation |
| Pitch | 2.0 mm | JST PH product profile, Specification; PH catalog title |
| Current rating | 2 A AC/DC (AWG #24) | JST PH catalog, Specifications |
| Voltage rating | 100 V AC/DC | JST PH catalog, Specifications |
| Temperature range | -40°C to +105°C, including temperature rise from applied current | JST PH catalog, Specifications |
| Insulation resistance | 1,000 MΩ min. | JST PH catalog, Specifications |
| Withstanding voltage | 800 VAC for one minute with no breakdown or flashover | JST PH catalog, Specifications |
| Applicable wire | AWG #32 to AWG #24; conductor area 0.032 mm² to 0.22 mm²; insulation O.D. 0.5 mm to 1.5 mm | JST PH catalog, Specifications and Contact table |
| PCB thickness | 0.8 mm to 1.6 mm | JST PH catalog, Specifications |
| Header dimensions | A = 2.0 mm; B = 5.9 mm | JST PH catalog, Header (Through-hole type) table, 2-circuit row |
| Header materials | Copper-alloy tin-plated posts; natural-white PA base housing | JST PH catalog, Header (Through-hole type), Material and Surface finish |
Verified against the manufacturer datasheet on 2026-07-10. Confirm the current revision before production use.
Alternatives
- B2B-PH-K-S: Two-circuit top-entry through-hole header in the same PH family. It changes mating direction, so it is not a placement-neutral substitute.
- S2B-PH-SM4-TB: Two-circuit side-entry SMT header in the same PH family. It needs the SMT land pattern and reinforcement pads rather than S2B-PH-K-S through holes.
- S3B-PH-K-S: Three-circuit side-entry through-hole PH header. It shares the 2.0 mm pitch and construction but adds one circuit and has a 7.9 mm catalog B dimension.
Common questions
- What mates with S2B-PH-K-S?
- Use the PHR-2 two-position housing with PH crimp contacts matched to the cable gauge. JST lists SPH-004T-P0.5S for AWG #32 to #28 and SPH-002T-P0.5S for AWG #30 to #24.
- Is S2B-PH-K-S the same as a 2.54 mm two-pin header?
- No. JST PH uses a 2.0 mm pitch and a keyed shroud. A 2.54 mm footprint will not fit and a generic 0.1-inch cable housing will not mate.
- Can S2B-PH-K-S carry 2 A?
- JST rates the PH family at 2 A AC/DC with AWG #24 wire. Smaller wire, contact resistance, ambient temperature, enclosure temperature, and PCB copper can lower the practical current limit.
- What is the difference between S2B-PH-K-S and B2B-PH-K-S?
- S2B-PH-K-S is side entry, so the cable exits parallel to the PCB. B2B-PH-K-S is top entry, so the cable approaches perpendicular to the PCB. Both are two-circuit through-hole PH headers.
- Does the S2B-PH-K-S footprint orientation follow the top view?
- No. JST notes that its PCB layout is viewed from the connector mounting surface. Compare the mechanical drawing, pin numbering, and cable polarity before releasing the board.
Sources
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