COSINE Tier-1 distributor Jarwey｜DAQ switch: COS3157 analog path vs USB mux vs RF
Jarwey is a COSINE Tier-1 distributor—selection support, datasheets, samples and small lots, and lead-time coordination.
A DAQ or radio module often has three blocks that all get called a “switch”: a sensor or audio baseband path, a USB D+/D− pair, and a Sub-1G or 2.4G air interface. One general-purpose analog switch does not cover all three. Baseband cares about on-resistance and charge injection. USB needs a mux built for a differential pair. The air interface needs a transceiver, not an analog switch tied to an antenna.
This note only splits those three paths. The full SPST polarity and channel table already exists and is not reprinted here: analog switch family. Datasheets: contact Jarwey. A cross-reference is an evaluation path, not an unverified swap.
Three paths, three parts
| Path | Signal | Evaluate first | Do not | Product |
|---|---|---|---|---|
| Baseband | Sensor or audio, DC through audio bandwidth | One-of-two: COS3157ST SPDT, SOT-23-6. Left/right or two sensors that must move together: COS5A23159 dual, MSOP-10 | Treat a USB mux bandwidth number as on-resistance or charge injection | 988 / 993 |
| USB port select | D+/D− pair | COSTS3USB30E (TS3USB30E / FSUSB30 class) or COSUSB42MUX (FSUSB42 class), both MSOP-10 | Switch a high-speed pair with a general SPDT such as COS3157 | 994 / 995 |
| Air interface | Sub-1G or 2.4G | Sub-1G: COS8820. 2.4G: COS8830 | Use an analog switch or USB mux as an antenna switch or a radio | 1005 / 1006 |
COS3157ST can be evaluated against the TS5A3157 / FSA3157 class. COS5A23159 can be evaluated against the TS5A23159 class. When two channels must change on the same control edge, use the dual switch. Two independent SPDTs with separate GPIO timing are a different circuit. On-resistance, charge injection, and whether the signal sits inside the supply rails come from the datasheet.
Both USB muxes are MSOP-10. The split is the reference class plus bandwidth and logic levels in the datasheet, not the package outline. Eye diagram, insertion loss, and intra-pair skew are board measurements. An audio-switch on-resistance does not describe a USB edge.
The radio is neither row above. Catalog figures, confirm on the datasheet: COS8820 is Sub-1GHz, average TX about −20 to 10 dBm, cascaded RX noise figure about 5 dB. COS8830 is 2.4GHz, average TX about −20 to 7 dBm, noise figure about 5 dB. Protocol, channel, and conducted power are not settled by those ranges. Family page: Sub-1G/2.4G transceivers.
Seven checks before layout
- Domain first: DC/audio, a USB pair, or Sub-1G/2.4G.
- Baseband swing: keep the signal inside the switch rails; put on-resistance and charge injection in the error budget.
- Two channels together: stereo or dual sensors use COS5A23159, not two SPDTs with separate timing.
- USB stays paired: D+/D− go through a USB mux. A general SPDT is not the high-speed path.
- Which USB mux: compare COSTS3USB30E and COSUSB42MUX on bandwidth and logic from the datasheet.
- Radio: Sub-1G starts at COS8820, 2.4G at COS8830. Do not land the antenna on an analog switch.
- Samples: datasheet and small lots from Jarwey; qualify on the board before volume.
Datasheets and inquiry
- COS3157ST analog switch
- COS5A23159 dual analog switch
- COSTS3USB30E USB switch
- COSUSB42MUX USB switch
- COS8820 Sub-1G transceiver
- COS8830 2.4G transceiver
Jarwey · COSINE Tier-1 distributor · kerry.w@jarwey.cn · Contact.
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