COSINE Tier-1 distributor Jarwey｜COS3157 stops at 5.5 V; same SOT-23-6 SPDT COS4561 starts at 3 V
Jarwey is a COSINE Tier-1 distributor and can line up the datasheet, samples, and a build schedule. A 12 V industrial sense rail and a 1.8 V codec rail are often both drawn as “one SPDT, SOT-23-6.” The 2025 COSINE catalog does not treat those rails as one row.
This note answers only the supply split. COS3157ST follows the COS3157 row: one SPDT, 1.65 V to 5.5 V, 4.5 Ω, 300 MHz at −3 dB. COS4561TR follows the COS4561 row: one SPDT, 3 V to 16 V, 3.6 Ω, 90 MHz at −3 dB. Both catalog rows list quiescent current under 1 µA. A rail above 5.5 V never lands on COS3157. A rail below 3 V never lands on COS4561. Matching the package name is not a swap.
Neither product page hosts a PDF. Ask Jarwey for the datasheet and check the catalog numbers against that document’s test conditions before the BOM is frozen. Alternate part numbers on the pages are evaluation candidates, not an unverified drop-in. Path assignment, the COS4514TR / COS4515TR logic pair, and the two USB MSOP-10 devices already have their own notes: signal-path split, SPST complement, USB MSOP-10 pair. The family index stays at the analog-switch table.
Three catalog rows that decide the rail
| Catalog row / page | Channel | VCC | ICC | RON | −3 dB bandwidth | Package as printed |
|---|---|---|---|---|---|---|
| COS3157 stocked COS3157ST | 1 × SPDT | 1.65–5.5 V | <1 µA | 4.5 Ω | 300 MHz | Catalog cell stacks SOT-23-6 and SC70-6. The live page marks SOT-23-6 only |
| COS4561 stocked COS4561TR | 1 × SPDT | 3–16 V | <1 µA | 3.6 Ω | 90 MHz | Catalog and the live page both say SOT-23-6 |
| COS12A12511 page 992 | 1 × SPDT | 3–16 V | <1 µA | 3.6 Ω | 100 MHz | Catalog cell stacks SOP-8 and MSOP-8. The live page says MSOP-8. Not a SOT-23-6 footprint |
The header on that catalog sheet is channel, type, VCC, ICC, RON, bandwidth at −3 dB, and package. It does not label RON as typical or maximum, so the figures stay as printed until the datasheet defines the condition. The COS4561TR page title reads “analog switch / multiplexer” and its function line does not say SPDT. The SPDT mark is the catalog type column. Pin names are not in the catalog; do not invent a pin map from the shared SOT-23-6 outline.
Page alternates, each one still to be verified: COS3157ST lists TS5A3157 / SN74LVC1G3157 / FSA3157; COS4561TR lists MAX4561; COS12A12511 lists TS12A12511 / DG469. Those three lists are not aliases of one device.
Rail checklist (7 items)
- Write the rail before the package. 1.65 V to 5.5 V is the COS3157 window. 3 V to 16 V is the COS4561 window. A rail outside both windows selects neither row.
- 5.5 V is the top of the COS3157 row. A 12 V sense rail does not move onto COS3157ST because the outline is SOT-23-6.
- 3 V is the bottom of the COS4561 row. A 1.8 V or 2.5 V switch domain does not move onto COS4561TR.
- Do not trade bandwidth for the lower ohm reading. Catalog bandwidth is 300 MHz on COS3157 and 90 MHz on COS4561. 4.5 Ω versus 3.6 Ω is not a swap argument by itself.
- Confirm the suffix before the land pattern. The COS3157 cell also stacks SC70-6. COS3157ST on the site is marked SOT-23-6. An SC70-6 footprint does not fit that ST page.
- The other wide-rail SPDT is COS12A12511. Same 3 V to 16 V window, catalog bandwidth 100 MHz, live package MSOP-8. It answers a footprint question. It does not turn COS4561TR into a 6-pin part.
- Datasheet, samples, and the build date travel together. Ask Jarwey for the datasheet that matches the catalog row, plus samples and a small-lot date. Freeze the BOM after the bench has seen supply, bandwidth, and the package suffix.
Pages and a quote
- COS3157ST · COS4561TR · COS12A12511
- Catalog application line: automotive and industrial control.
Send the analog rail, the signal bandwidth, and whether the footprint is SOT-23-6 or MSOP-8: kerry.w@jarwey.cn · Contact.
Jarwey · COSINE Tier-1 distributor · analog-switch selection and lead time · kerry.w@jarwey.cn · Contact.
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