DS1990R-F5

DS1990R-F5 iButton (guaranteed presence pulse)

R-variant that guarantees a presence pulse the instant the key touches a live bus.

Electrically identical to the DS1990A — same 64-bit read-only ROM, same family code 01h. The documented difference is behavioural: the DS1990R guarantees a presence pulse on contact (after power-on reset) when the button touches an already-powered 1-Wire bus, so the reader detects the key reliably the moment it lands. Preferred where presence-on-contact detection has to be certain on every touch.

Key features

• Guarantees a presence pulse on contact (after power-on reset) with a live 1-Wire bus — reliable detection the instant the key lands.
• Electrically identical to DS1990A: same read-only 64-bit ROM, same family code 01h.
• Preferred where presence-on-contact detection must be certain on every single touch.
• Same F5 MicroCan, same 1-Wire interface and reader compatibility as the standard key.

Specifications

Chip / compatibility	DS1990R compatible · family code 01h
Memory	64-bit ROM, read-only (8-bit family + 48-bit serial + 8-bit CRC)
Package	F5 can
Protocol	1-Wire, 16.3 kbit/s
Operating temperature	−40 °C … +85 °C

Inside the stainless can

A 0.25 mm solid stainless shell, a UV-stable polypropylene grommet isolating lid from base, and the die bonded inside. Lid = data contact, base = ground return.

Ordering information

MOQ	100 pcs
Lead time	3–7 days for stock items, 10–15 days for OEM
Packing	Bulk ESD bags (100–200 pcs/bag, 2 bags/carton); blister or header cards for retail on request
Samples	Free samples for volume buyers — courier at cost
Payment	T/T bank transfer; other terms negotiable for repeat orders
Shipping	DHL / FedEx / UPS air express; sea or rail freight for pallet volumes
Customization	ROM ranges · housing colours · laser logo · private label

Typical applications