How to source Touch Memory keys: a buyer’s checklist
What to verify before placing a volume order for iButton or TM keys — chip authenticity, read reliability, packaging, custom ROM ranges, MOQ, lead time and the questions worth asking any supplier.
-
Confirm what the chip actually is
Ask whether the quote is for an original manufacturer’s DS part or a TM alternative. Record the manufacturer, exact model, version and agreed specification on the proforma invoice. Do not infer interchangeability from the name: confirm the target device and firmware and approve a tested sample.
-
Test read reliability, not just first read
Agree the sample quantity and test plan with the supplier. Check repeated reading and registration on your actual devices and record their models and firmware. For RW1990, also check writing and rewriting with your own test ID. For TM1990A-F5 and RW1990 only: 10 free sample pieces, ready in 3 days; you pay sample shipping. 500 pieces are usually ready in 1 week. Transit time is additional.
-
Decide the ID range policy up front
For read-only keys, duplicate IDs across two batches will cause access conflicts on the same site. Ask the supplier how ranges are allocated and whether they can reserve a range for you. For large estates this is not a detail — it is the whole system.
-
Match packaging to how you sell
State the order quantity, whether you need bare buttons or assembled fobs, and the packaging format needed for installation, resale or retail. Confirm the available format, pieces per pack, marking and assembly or packing charges in writing. Compare the quoted options, including any repacking needed at destination.
-
Agree the QC standard before production
Agree written test methods, sampling and acceptance criteria for the supplied version, and request the recorded results. For fixed-ID keys, confirm ID format, reading and registration checks, and the required duplicate-ID controls within and across batches. For RW1990 blanks, agree the initial supplied state and separately test writing, rewriting, read-back and target-system acceptance. Define applicable housing, marking and packing checks as part of the same agreement.
-
Clarify shipping, duties and documentation
Compare the total cost to your destination, including goods, packing, freight and destination charges. Confirm shipping options, freight, responsibility for duties and taxes, and the documents available with the actual quotation. Check the required classification and documents with your destination customs broker; do not assume a particular shipping method is the lowest-cost option.
Planning a bulk purchase? Follow the checklist for your buying task: TM1990A-F5 for equipment projects · RW1990 wholesale supply
Record the sample version and the reader/controller model and firmware. Check the ROM format, family code and CRC against the quoted specification, then test reading and registration on the target system. For RW1990, use a writer that supports the supplied version to test writing and rewriting with your own test ID. Functional checks and laser markings alone do not establish manufacturer origin.
Dallas, Maxim and iButton are trademarks of their respective owners. Touch Memory China is not affiliated with these trademark owners.
