DS1990A vs TM1990A vs RW1990: what is the difference?
Compare read-only DS1990A and TM1990A with rewritable RW1990: ID type, writer support, sample checks and ordering terms for TM1990A-F5 and RW1990.
| Type | Rewritable | Protocol | Typical use | Notes |
|---|---|---|---|---|
DS1990A / DS1990R | No — factory-programmed, read-only | 1-Wire, 64-bit ROM | The original credential issued by system owners | The factory-set ID is read-only. Read-only describes whether that key can be rewritten; it does not by itself prevent another device from presenting the same ID. |
TM1990A | No — read-only | 1-Wire, 64-bit ROM | Fixed, read-only IDs for volume issuance | Uses the 1-Wire ROM interface. Confirm the reader/controller model and firmware, then test ID reading and registration on your actual system before a bulk order. |
RW1990 / RW1990.2 | Yes — with a writer supporting the specific blank version | 1-Wire emulation | Blank for key-cutting shops and duplicating services | A programmable ID blank intended for Dallas/1-Wire applications. Similar RW1990 version names do not establish the same write routine. Confirm the supplied version, writer and target system firmware, then test writing, rewriting and reading with your own test ID. |
TM08v2 | Yes — multi-format | 1-Wire + Cyfral + Metakom | Multi-format blank for mixed intercom systems | Supports multiple format families, but acceptance depends on the specific blank version, writer, panel and firmware. Confirm the required format and test samples on each target system. |
TM-01A / RW2000 (OTP) | Once — programs a single time, then locks | TM-01A: 1-Wire · RW2000: Cyfral / Metakom | One-time-programmable credentials where supported | OTP prevents rewriting the programmed blank; it does not by itself prevent its readable ID from being copied to another device. Confirm the exact version, write-lock behaviour and acceptance by the target panel before purchase. |
Cyfral / Metakom | Format, not a part number | Proprietary, not 1-Wire | Legacy CIS intercom systems | A similar contact shape does not establish the same format. Check the actual panel and credential documentation; the Cyfral or Metakom brand alone does not identify every supported format. |
Original DS1990A documentation (Analog Devices). These specifications describe the original part. Validate TM1990A and RW1990 samples with your actual equipment.
Planning a bulk purchase? Follow the checklist for your buying task: TM1990A-F5 for equipment projects · RW1990 wholesale supply
Ask the supplier to identify the manufacturer, exact part number and version in the quote. A compatible alternative is not the original manufacturer’s part. Check current documentation and sourcing evidence when your project requires a specific original component.
RW1990 is a Dallas/1-Wire blank. Do not select it from the intercom brand or key shape alone: confirm the panel model, firmware and credential format. Cyfral, Metakom and contactless RFID formats need a matching solution, and acceptance should be checked on the actual system.
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