PTS645SM43SMTR92

1. Overview

The C&K PTS645SM43SMTR92 LFS is a surface-mount (SMD) momentary tactile push-button switch from C&K's PTS645 series, which covers 6.0×6.0mm top-actuated TACT switches in a wide range of actuator heights and actuation forces. C&K (C&K Components / C&K Switches) was acquired by Littelfuse, so the part appears in catalogs under both the C&K and Littelfuse brand names with no change to specs. The PTS645 series is one of the most widely stocked and broadly supported 6mm TACT switch families in the industry, available from virtually every major authorized distributor globally.

Part number decode — PTS645SM43SMTR92:

• PTS645: 6.0×6.0mm tactile switch series
• SM: Surface Mount (SMD), gull-wing / J-bend terminals
• 43: Actuator height = 4.3mm above PCB
• SM: Round button actuator (second SM = shape/material code, PA66 nylon)
• TR: Tape & Reel packaging
• 92: Lead-free / RoHS-compliant process option (LFS suffix confirms this)

2. User Sentiment

No forum or community sentiment data was found specific to this part number. As a standard industrial 6×6mm SMD tactile switch, the PTS645 series is a commodity component widely used without generating substantial hobbyist discussion. The part is designed for high-volume automated PCB assembly (tape-and-reel), so its end-users are primarily electronics manufacturers rather than individual hobbyists. Its availability across 90,000+ units at DigiKey and global distribution through Mouser, Farnell, Arrow, Newark, TME, and LCSC (¥2.12 CNY) reflects consistent demand in industrial and consumer electronics design.

3. Real-World Applications

The PTS645SM43SMTR92 LFS targets consumer electronics, instrumentation, computer products, and industrial equipment — all confirmed in the C&K datasheet application list. The 4.3mm actuator height suits panel-mount or through-bezel assemblies where a modest protrusion is needed. With a 160gf (1.6N) actuation force, it provides moderate resistance suitable for control panels, test instruments, keyboards, and handheld devices. The SMD gull-wing form factor makes it compatible with standard reflow soldering in high-volume production.

4. Technical Specifications

• Type: Tactile Switch (TACT), momentary, SPST-NO (normally open)
• Body size: 6.0 × 6.0 mm
• Actuator height: 4.3mm above PCB
• Actuator shape: Round button, blue, PA66 nylon (polyamide)
• Mount type: Surface Mount (SMD), gull-wing / J-lead terminals
• Actuation force: 160gf / 1.57–1.6N
• Contact rating: 50mA @ 12VDC (0.05A / 12V)
• Mechanical life: 100,000 cycles
• Operating temperature: −20°C to +85°C (DigiKey/LCSC); TME states −20°C to +60°C
• Contact resistance: ≤100mΩ
• Insulation resistance: ≥100GΩ
• Contact plating: Silver
• Sealing: IP40
• Packaging: Tape & Reel (TR), 1,000 pcs/reel
• RoHS: Yes (LFS / suffix "92" = lead-free)
• Weight: 0.34g

5. Ordering & Compatibility

Available from DigiKey (stock 91,214+, $0.36/1 → $0.18/10k T&R), Mouser, Arrow, Farnell/element14, Newark, TME, Rutronik, LCSC (¥2.12), and Chip1Stop. The part is listed under both C&K (MFR) and Littelfuse (brand owner post-acquisition). Alternate PN formats: PTS645SM43SMTR 92 LFS, PTS645SM43SMTR92LFS, PTS645SM43SMTR92-LFS. The PTS645 series offers multiple actuator heights (e.g., SM23 = 2.3mm, SM30 = 3.0mm, SM43 = 4.3mm, SM50 = 5.0mm) and force options, so designers can substitute within the same footprint. CAD models (schematic symbol, PCB footprint, 3D model) are freely available from SnapMagic/SnapEDA and ComponentSearchEngine for Eagle, Altium, OrCad, KiCad.

6. Known Issues

No significant issues reported. The operating temperature upper limit has a minor discrepancy between sources: DigiKey and LCSC list +85°C while TME lists +60°C; the C&K datasheet value of +85°C is likely authoritative. The 160gf actuation force is confirmed across DigiKey, Farnell, Kynix, and the Rutronik listing; one source (Sensible Micro) quotes 1.57N (≈160gf), which is consistent. No counterfeit or quality alerts found; the part sources from multiple authorized distributors and shows a healthy inventory trend.