DS28EC20+T - 20Kb 1-Wire EEPROM, TO-92-3 | Analog Devices
MPN: DS28EC20+T ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $2.85 | $2.85 |
| 10 | $2.62 | $26.20 |
| 100 | $2.31 | $231.00 |
| 500 | $2.05 | $1,025.00 |
| 1,000 | $1.82 | $1,820.00 |
DS28EC20+T Overview
An EEPROM (Electrically Erasable Programmable Read-Only Memory) is a type of non-volatile memory that retains data when power is removed and supports byte-level or page-level electrical erase and rewrite cycles. The DS28EC20 belongs to the EEPROM > non-volatile memory > memory IC > integrated circuit taxonomy. Data is written to a 32-byte scratchpad, verified by reading it back, and then committed to the EEPROM array - this scratch-and-copy flow gives the DS28EC20 strong write-verify integrity even though it shares a single wire with power and data.
Key features of the DS28EC20+T include a 20Kb (2.5KB) user-accessible array with 256-bit page granularity for efficient block writes, parasite power operation (the device harvests operating power directly from the 1-Wire data line), an internal CRC16 generator on the 64-bit ROM and on scratchpad reads for robust error detection, and a unique per-device serial number that doubles as a node address on a multidrop bus. The 1-Wire interface requires only a single data line plus ground, simplifying cable runs for remote or sensor-mounted identification nodes.
Architecturally the DS28EC20 combines a CMOS EEPROM array with a 1-Wire front end and a hard-wired 64-bit serial number. The CMOS process yields low active and standby current budgets that match the modest energy available from the 1-Wire pull-up, while the dedicated scratchpad decouples host-side write latency from EEPROM programming time. The TO-92-3 package matches the legacy Dallas Semiconductor form factor, allowing direct mechanical and pin-compatibility upgrades of older 1-Wire EEPROM designs.
Typical applications include electronic accessory and consumable identification, board serialization and anti-counterfeiting, building automation node addressing, industrial sensor tagging, and any multidrop 1-Wire network where each node must carry its own unique identifier plus user-writable storage. Because the device powers itself from the data line, no local supply rail is required at the node.
When designing with the DS28EC20+T, observe strict 1-Wire timing: the host must provide a strong pull-up to 5V (or 3.3V in low-voltage mode), respect t_RSTL/t_RSTH/t_PDL/t_PDH reset and presence timing windows, and verify each scratchpad write with a CRC16 match before issuing the Copy & Lock command. Note that the internal ROM copy-lock mechanism is one-time per page, so plan page allocation before programming the lock state. The TO-92 leads should be clipped or potted when used in mechanically exposed installations.
This page synthesizes distributor pricing from DigiKey, Mouser and LCSC, pin-compatible 1-Wire EEPROM alternatives, and practical 1-Wire bus design notes not found in the bare manufacturer datasheet, providing an engineer-grade reference for sourcing and applying the DS28EC20+T.
Drop-in alternatives for DS28EC20+T — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with DS28EC20+T (same form factor and footprint) — differing in Interface, Memory Organization, Memory Type, Operating Temperature, Scratchpad Size.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
DS28EC20+
✅ Drop-In✓ In Stock
$2.05 / Unit
View Datasheet →DS28EC20P+T
✅ Drop-In📋 Reference alternative (not in catalog)
DS28EC20+T Maximum Ratings & Electrical Characteristics
| Memory Type | EEPROM (Non-Volatile) |
| Memory Size | 20 Kbit (20480 bit) |
| Memory Organization | 80 pages x 256 bits (plus 1 control page) |
| Scratchpad Size | 32 bytes (256 bits) |
| Interface | 1-Wire (single-conductor, parasite-power capable) |
| Bus Protocol | Standard Dallas 1-Wire |
| Unique ID | 64-bit factory-lasered ROM registration number |
| Error Detection | CRC16 on ROM and scratchpad reads |
| Write Granularity | 256-bit page |
| Package | TO-92-3 (through-hole) |
| Mounting Type | Through Hole |
| Operating Temperature | -40C to +85C |
| Supply Voltage | Parasite power from 1-Wire data line (2.8V-5.25V host pull-up) |
| RoHS Status | Compliant |
| Lead Finish | Matte Tin (Pb-free) |
DS28EC20+T Pin Configuration
| Pin 1 | GND — Ground reference for the 1-Wire bus |
| Pin 2 | DQ — 1-Wire data input/output (also parasite-power input via internal diode) |
| Pin 3 | NC — Not connected (per datasheet, lead present for mechanical stability) |
Typical Applications
DS28EC20+T is suitable for 6 applications: Electronic Accessory & Consumable Authentication, PCB Serialization & Anti-Counterfeit, Building Automation Node Addressing, Industrial Sensor Tagging, Medical Device Calibration Memory, Multidrop 1-Wire Network Backbone.
Electronic Accessory & Consumable Authentication
The DS28EC20+T fits accessory authentication because its 20Kb of user-writable EEPROM plus unique 64-bit ROM ID lets each cartridge, printer head, or medical consumable carry both a tamper-resistant identity and per-unit calibration / lifecycle counters. The 1-Wire single-wire interface means the host MCU needs only one GPIO plus ground to talk to the consumable, dramatically simplifying the cable harness and connector. With 256-bit page writes and CRC16 scratchpad verification, batch lot codes and expiry dates can be written at factory time without risk of bit-errors during field programming.
Recommended
PCB Serialization & Anti-Counterfeit
The DS28EC20+T fits PCB serialization because its factory-lasered 64-bit ROM ID provides a guaranteed-unique board identifier and its 20Kb of writable EEPROM can hold board-level test logs, firmware versions, and calibration constants. The TO-92-3 form factor can be socketed or hand-soldered on a test fixture pad, allowing it to be added late in the manufacturing flow without disturbing the main PCB layout. Each board's unique ID plus scratchpad-verified user data creates a complete anti-counterfeiting record accessible via any standard 1-Wire host driver on a single test pin.
Recommended
Building Automation Node Addressing
The DS28EC20+T suits building-automation node addressing because parasite power from the 1-Wire line eliminates the need for a local power supply at each sensor or actuator node, reducing wiring cost across a multidrop bus. The 80 pages of 256-bit storage allow per-node configuration (room number, zone ID, calibration offsets) to be written once at install and read back by a central HVAC or lighting controller. CRC16 scratchpad verification protects configuration writes from corruption on long cable runs, a frequent challenge in commercial-building wiring.
Recommended
Industrial Sensor Tagging
The DS28EC20+T works for industrial sensor tagging because the 1-Wire single-wire interface lets a single MCU GPIO poll dozens of sensors hung on a multidrop bus, while the per-device 64-bit ROM ID gives each tag a hard-unique address. With 20Kb of writable EEPROM, each sensor can carry last-calibration date, max recorded temperature, hours-of-operation counter, and an OEM signature field that survives in-field firmware updates. Parasite power means the tag can be retrofitted to legacy 4-20mA or RS-485 sensor housings with only a ground and data wire.
Recommended
Medical Device Calibration Memory
The DS28EC20+T is suitable for medical-device calibration memory because its 20Kb of write/erase-capable EEPROM holds calibration coefficients, service-log timestamps, and sterilization-cycle counters, all readable through a single 1-Wire probe during routine maintenance. The CRC16-verified scratchpad ensures that mis-calibration writes are caught before being committed to the array, a safety-critical property for devices subject to IEC 62304 documentation. The TO-92-3 package can be encapsulated inside the device housing for a non-replaceable, factory-sealed calibration token.
Recommended
Multidrop 1-Wire Network Backbone
The DS28EC20+T is well suited as a backbone element in multidrop 1-Wire networks because every device on the segment carries its own 64-bit ROM registration number, and the host can Search ROM to discover and address each node individually even when many are physically paralleled on the same wire. The 80 user pages mean a single DS28EC20 can hold node-level configuration, telemetry history, or per-device cryptographic material without needing an external EEPROM. Parasite power keeps the bus topology simple (one wire + ground), which is the main reason 1-Wire remains popular for cable-plant diagnostics and remote sensor arrays.
Recommended
Recommended Products Summary
Engineering reference data for DS28EC20+T — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | DS28EC20+ | DS28EC20P+T | DS2431+ |
|---|---|---|---|---|
| Package | TO-92-3 (through-hole) | TO-92-3 (through-hole) - same | TSOC-6 (SMD) - different mechanical | TO-92-3 or TSOC - same option |
| Brand | Analog Devices (Maxim Integrated) | Analog Devices | Analog Devices | Analog Devices |
| Memory Size | 20 Kbit (80 x 256-bit pages) | 20 Kbit - identical | 20 Kbit - identical | 1 Kbit (4 x 256-bit pages) - 20x smaller |
| Interface | 1-Wire (parasite-power capable) | 1-Wire - identical | 1-Wire - identical | 1-Wire - identical |
| Unique ROM ID | 64-bit factory-lasered | 64-bit - identical | 64-bit - identical | 64-bit - identical |
| Page Write Granularity | 256 bits per page | 256 bits - identical | 256 bits - identical | 256 bits - identical |
| Error Detection | CRC16 on scratchpad | CRC16 - identical | CRC16 - identical | CRC16 - identical |
| Operating Temperature | -40C to +85C | -40C to +85C - identical | -40C to +85C - identical | -40C to +85C - identical |
Key Differentiators
- 20x larger memory than the family-standard DS2431 (vs DS2431+)
- TO-92-3 through-hole package for legacy or socketed installations (vs DS28EC20P+T (TSOC-6))
- Tape-and-reel packaging for automated through-hole insertion (vs DS28EC20+ (bulk))
Design Notes
Estimated: The DS28EC20+T draws its operating current from the 1-Wire DQ pin during the host's strong pull-up window, so the host must provide a 4.7kOhm pull-up to a 2.8V-5.25V rail. During Copy & Lock (EEPROM programming) the device asserts a stronger continuous pull-up requirement for up to 10 ms; verify the host driver maintains the strong pull-up throughout this window or the write will silently abort without CRC verification.
On a multidrop 1-Wire segment, keep cable capacitance under approximately 5 nF total by limiting stub length and avoiding star topologies. Place the DS28EC20+T TO-92 leads close to the cable entry point to minimize stub capacitance; if a long cable run is unavoidable, add a 1kOhm series resistor at the host to damp reflections. Use a shielded cable for industrial runs and ground the shield at one end only.
Critical: The Copy & Lock command is one-time per page - once a page is locked it can never be written again on that individual DS28EC20. Plan page allocation (life counters vs static configuration vs read-only logs) before issuing any Copy & Lock command, or you will permanently waste user EEPROM. Also, do not assume the DS28EC20+T powers up in a known data state - the host must always issue a Read Scratchpad or Read Memory command to refresh its cache after bus reset.
The 1-Wire reset pulse must be at least 480 us low followed by 480 us high before the DS28EC20+T drives a 60-240 us presence pulse. Source: Analog Devices 1-Wire protocol documentation. Any host driver that does not respect t_RSTL >= 480 us will fail to enumerate the device; on slow MCUs, use a hardware timer rather than software delay loops to guarantee timing across temperature and voltage.
Compliance Information
RoHS and REACH compliant per DigiKey product listing. Not AEC-Q100 qualified - this is a general-purpose commercial memory IC. Lead-free matte-tin finish. Halogen-free status not stated by the manufacturer in the provided data; consult the Analog Devices environmental compliance page for confirmation.
