DS2401 Silicon Serial Number Benefits and Features Pin Configurations Guaranteed Unique 64-Bit ROM ID Chip for TO-92 Absolute Traceability TSOC o Unique, 64-Bit Registration Number (8-Bit DS2401 Family Code + 48-Bit Serial Number + 8-Bit CRC Tester) o 8-Bit Family Code Specifies DS2401 Communications Requirements to Reader TOP VIEW Minimalist 1-Wire Interface Lowers Cost and Interface Complexity o Multiple DS2401 Devices Can Reside on a Common 1-Wire Net o Built-In Multidrop Controller Ensures Compatibility with Other 1-Wire Net Products 1 2 3 o Reduces Control, Address, Data, and Power to a Single Pin and Communicates at Up to 16.3kbps o Presence Pulse Acknowledges When the Reader First Applies Voltage 1 2 3 o Low-Cost TO-92, SOT-223, and TSOC TOP VIEW Surface-Mount Packages BOTTOM VIEW o TO-92 Tape-and-Reel Version with Leads Flip Chip, Top View Bent to 100-mil Spacing (Default) or with with Laser Mark, 01rrd Straight Leads (DS2401-SL) Contacts Not Visible. rrd = Revision/Date Wide Voltage and Temperature Operating 1 2 Ranges Enables Robust System Performance o Extended 2.8V to 6.0V Range (DS2401) TOP VIEW DS2401 o Zero Standby Power Required + o -40C to +85C Industrial Temperature A Range 1 2 1 2 B Applications PCB Identification Network Node ID WLP Equipment Registration Pin Descriptions PIN NAME SOT- FLIP TO-92 TSOC WLP 223 CHIP DATA (DQ) 2 2 2 1 A1, B1 GROUND 1 1, 4 1 2 A2, B2 N.C. (No 3 3 36 Connect) 1-Wire is a registered trademark of Maxim Integrated Products, Inc. 19-5860 Rev 11/23/21 1 Analog Devices Ordering Information PART TEMP RANGE PIN-PACKAGE DS2401+ -40C to +85C 3 TO-92 DS2401A+ -40C to +85C 3 TO-92 DS2401+T&R -40C to +85C 3 TO-92 (formed leads) DS2401A+T&R -40C to +85C 3 TO-92 (formed leads) DS2401-SL+T&R -40C to +85C 3 TO-92 (straight leads) DS2401P+ -40C to +85C 6 TSOC DS2401AP+ -40C to +85C 6 TSOC DS2401P+T&R -40C to +85C 6 TSOC DS2401AP+T&R -40C to +85C 6 TSOC DS2401Z+ -40C to +85C 4 SOT-223 DS2401Z+T&R -40C to +85C 4 SOT-223 DS2401X1-S T -40C to +85C 2 Flip Chip (2.5k pieces) DS2401X-S+T -40C to +85C 4 WLP +Denotes a lead(Pb)-free/RoHS-compliant package. T&R/T = Tape and reel. SL = Straight leads. Denotes a RoHS-compliant device that may include lead that is exempt under the RoHS requirements. Description The DS2401 enhanced silicon serial number is a low-cost, electronic registration number that provides an absolutely unique identity which can be determined with a minimal electronic interface (typically, a single port pin of a microcontroller). The DS2401 consists of a 64-bit ROM that includes a unique 48-bit serial number, an 8-bit CRC, and an 8-bit Family Code (01h). Data is transferred serially via the 1-Wire protocol that requires only a single data lead and a ground return. Power for reading and writing the device is derived from the data line itself with no need for an external power source. The DS2401 is an upgrade to the DS2400. The DS2401 is fully reverse-compatible with the DS2400 but provides the additional multi-drop capability that enables many devices to reside on a single data line. The familiar TO-92, SOT-223 or TSOC package provides a compact enclosure that allows standard assembly equipment to handle the device easily. Operation The DS2401s internal ROM is accessed via a single data line. The 48-bit serial number, 8-bit family code and 8-bit CRC are retrieved using the Maxim 1-Wire protocol. This protocol defines bus transactions in terms of the bus state during specified time slots that are initiated on the falling edge of sync pulses from the bus master. All data is read and written least significant bit first. 1-Wire Bus System The 1-Wire bus is a system which has a single bus master system and one or more slaves. In all instances, the DS2401 is a slave device. The bus master is typically a microcontroller. The discussion of this bus system is broken down into three topics: hardware configuration, transaction sequence, and 1- Wire signaling (signal type and timing). Hardware Configuration The 1-Wire bus has only a single line by definition it is important that each device on the bus be able to drive it at the appropriate time. To facilitate this, each device attached to the 1-Wire bus must have an open-drain connection or 3-state outputs. The DS2401 is an open-drain part with an internal circuit equivalent to that shown in Figure 2. The bus master can be the same equivalent circuit. If a bidirectional pin is not available, separate output and input pins can be tied together. The bus master requires a pullup 2 Analog Devices