DS24B33+ - 4Kb 1-Wire EEPROM, TO-92 | Analog Devices
MPN: DS24B33+ ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $2.95 | $2.95 |
| 10 | $2.72 | $27.20 |
| 100 | $2.38 | $238.00 |
| 500 | $2.15 | $1,075.00 |
| 1,000 | $1.92 | $1,920.00 |
DS24B33+ Overview
A 1-Wire EEPROM is a non-volatile memory device that combines data storage with a one-wire serial communication interface pioneered by Dallas Semiconductor (now part of Analog Devices). Unlike I²C or SPI EEPROMs that require two or four signal lines, 1-Wire parts use only a single data line plus ground, allowing power and data to share the same conductor via parasitic power. Within the broader memory hierarchy, the DS24B33 sits in the EEPROM family (electrically erasable programmable read-only memory), which is a subset of non-volatile memory (NVM) and ultimately semiconductor memory ICs.
Key features include 200K write/erase cycle endurance per page, a 32-byte scratchpad for verified data transfer, sixteen 32-byte pages of EEPROM, an on-chip CRC-16 generator for data transfer validation, and an operating voltage range of 2.8V to 5.25V. Data writes are protected by a strict read/write protocol that verifies the scratchpad contents against the master before committing to EEPROM, eliminating partial-write corruption.
The DS24B33 is software- and pin-compatible with the legacy DS2433, providing a modern silicon replacement that uses newer semiconductor technology. The TO-92-3 package supports hand-up (uidance-style hand-solderable) installation in low-volume and field-deployed applications where surface-mount is impractical, such as outdoor sensor enclosures, automotive wiring harnesses, and access control tokens.
Typical applications include PCB identification and authentication, consumable authentication (ink cartridges, medical sensors), access control iRODs (ibutton ID rings), environmental sensor calibration storage, inventory tracking, and iButton (button-style ID) accessories. The unique 64-bit ROM registration number enables 1-Wire multidrop networks where many devices share a single bus.
A key design consideration is the requirement for a 4.7 kΩ pull-up resistor on the 1-Wire data line, plus proper ESD protection. For long cable runs, the strong pull-up during write/erase cycles and proper ground return are essential for reliable operation.
This page synthesizes synthesizer-equipped manufacturer datasheet data, distributor stock, includes, applies, applies, design considerations and practical design notes not found in the manufacturer datasheet alone.
Drop-in alternatives for DS24B33+ — 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 DS24B33+ (same form factor and footprint) — differing in Interface, Mounting Type, Memory Size, Memory Type, Operating Temperature.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
DS24B33+T&R
✅ Drop-In📋 Reference alternative (not in catalog)
DS2433+
✅ Drop-In✓ In Stock
$1.92 / Unit
View Datasheet →DS24B33+ Specifications
| Memory Type | EEPROM (Non-Volatile) |
| Memory Size | 4 Kbit (4096 bits) |
| Memory Organization | 16 pages x 256 bits (16 pages x 32 bytes) |
| Interface | 1-Wire (single-conductor serial) |
| Scratchpad Size | 32 bytes (256 bits) |
| Write/Erase Endurance | 200K cycles per page |
| Unique ROM Registration | 64-bit factory-programmed laser ROM |
| Operating Voltage | 2.8 V to 5.25 V |
| Write/Erase Time (typical) | 2 µs (page write cycle) |
| Operating Temperature | -40°C to +85°C |
| Package | TO-92-3 (through-hole) |
| Pin Count | 3 |
| Mounting Type | Through-Hole |
| RoHS Status | Compliant |
| On-Chip CRC | CRC-16 generator |
DS24B33+ Pin Configuration
| Pin 1 | GND — Ground reference; identified by the flat side of the TO-92 package |
| Pin 2 | DQ — 1-Wire data I/O line; open-drain, requires 4.7 kΩ pull-up to VDD |
| Pin 3 | VDD — Power supply input (2.8 V to 5.25 V); can be left floating for parasitic-power mode |
Typical Applications
DS24B33+ is suitable for 6 applications: PCB Identification and Authentication, Consumable Authentication (Ink Cartridges, Medical Sensors), Access Control iButton Tokens, Environmental Sensor Calibration Storage, Inventory Tracking and Asset Tags, iButton-Style Identification Accessories.
PCB Identification and Authentication
The DS24B33+ delivers unique 64-bit ROM IDs for PCB authentication, anti-counterfeiting, and board-revision tracking. The factory-programmed serial number, combined with the CRC-16 generator, enables cryptographic-style challenge sequences over the single-wire 1-Wire bus, allowing a host MCU to verify board authenticity at power-up. The 4 Kbit user memory (16 pages of 32 bytes) stores calibration constants, board revision codes, or cryptographic keys alongside the unique ID. With 200K write/erase endurance per page, the device supports field-updatable configuration without wear concerns. The TO-92-3 package hand-solders easily onto through-hole identification pads near board edges, where surface-mount identification EEPROMs cannot fit. Recommended companion parts include MAX31820 ambient temperature sensors and MAX31826 digital temperature sensors for combined identification-plus-sensing nodes.
Recommended
Consumable Authentication (Ink Cartridges, Medical Sensors)
The DS24B33+ provides secure authentication for consumables such as ink cartridges, medical sensors, and printer consumables. The unique 64-bit registration number combined with the 32-byte scratchpad and CRC-16 verification protocol prevents counterfeit consumables from being used with genuine host equipment. Writes to the 4 Kbit EEPROM are protected by a strict read/write protocol that verifies scratchpad contents against the host before committing to memory, eliminating partial-write corruption. With 200K write/erase cycles per page and 10-year retention, the device survives the full lifetime of most consumables. The TO-92-3 form factor fits inside cartridge housings where SMT is impractical. Recommended companion parts include MAX31855 thermocouple-to-digital converters and DS1803 digital potentiometers used in medical sensor signal conditioning paths.
Recommended
Access Control iButton Tokens
The DS24B33+ is used in access control iButton-style tokens, where the unique 64-bit registration number serves as a credential identifier. Each token carries its own unalterable factory-programmed ID, and the host system grants entry based on the registered ID list. The single-wire 1-Wire protocol means access control readers need only one data line plus ground, dramatically simplifying reader hardware compared to RFID or NFC alternatives that require antennas. The 4 Kbit user memory can hold access logs, employee data, or biometric templates. With 2.8 V to 5.25 V operation and -40°C to +85°C industrial temperature range, the device operates reliably in outdoor and industrial access control environments. The TO-92-3 form factor suits hand-held tokens. Recommended companion parts include DS1481 token ring network controllers and DS2409 1-Wire hubs for multidrop reader networks.
Recommended
Environmental Sensor Calibration Storage
The DS24B33+ stores factory calibration data for environmental sensors, eliminating per-sensor trim components in production cost because calibration data is digitally stored rather than trimpot-adjusted. Each sensor module receives a DS24B33+ programmed with calibration coefficients, linearization tables, and serial numbers during factory test. At runtime, the sensor host reads the calibration data via the 1-Wire protocol and uses it to correct raw sensor readings. The 200K write/erase endurance supports in-field recalibration cycles when sensors drift over time. The 4 Kbit memory (16 pages of 32 bytes) accommodates multiple calibration datasets, drift compensation tables, and installation metadata. With low power consumption suitable for battery-powered wireless sensor nodes, the device suits IoT environmental monitoring deployments. Recommended companion parts include MAX31760 precision fan speed controllers and DS600 analog temperature sensors for combined calibration-plus-monitoring systems.
Recommended
Inventory Tracking and Asset Tags
The DS24B33+ serves as a low-cost electronic asset tag for inventory tracking, where the unique 64-bit registration number provides unambiguous asset identification across supply chains. A handheld 1-Wire reader can poll hundreds of tagged assets in seconds over the multidrop 1-Wire protocol, dramatically reducing inventory audit time versus barcode scanning. The 4 Kbit user memory stores asset metadata such as purchase date, location, custodian, and maintenance history. With 200K write/erase endurance, the device handles decades of field updates. The TO-92-3 through-hole form factor allows direct mounting on metal brackets, equipment chassis, and wiring harnesses where surface-mount identification EEPROMs cannot survive mechanical handling. The 10-year data retention ensures long-term record integrity for compliance and audit trails. Recommended companion parts include MAX1472 UHF transmitters and DS2751 battery fuel gauges for wireless asset tracking nodes.
Recommended
iButton-Style Identification Accessories
The DS24B33+ enables iButton-style identification accessories (button-style ID rings worn by personnel, attached to equipment, or embedded in tokens). Each iButton carries a unique 64-bit registration number plus 4 Kbit of user memory for personalization, medical records, or access credentials. The single-wire 1-Wire protocol allows momentary-contact reading: the user touches the iButton to a reader probe, momentary contact transfers the ID, and the host verifies identity. The TO-22 low-profile TO-92-3 form factor suits wearable applications where surface-mount identification EEPROMs are too bulky. With 2.8 V to 5.25 V operation, the device works with both battery-powered portable readers and mains-powered access control readers. Recommended companion parts include DS1481 token ring network controllers and DS2480B 1-Wire-to-UART bridges for reader hardware interfaces.
Recommended
Recommended Products Summary
Engineering reference data for DS24B33+ — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | DS24B33S+ | DS24B33+T&R | DS2433+ | DS1972 |
|---|---|---|---|---|---|
| Package | TO-92-3 (through-hole) | 8-SOIC (5.30 mm) - different footprint | TO-92-3 (through-hole, T&R) - same footprint | TO-92-3 (through-hole) - same footprint | iButton F5 microcan - different form factor |
| Brand | Analog Devices (formerly Maxim Integrated) | Analog Devices | Analog Devices | Analog Devices | Analog Devices |
| Memory Size | 4 Kbit (4096 bits) | 4 Kbit - same | 4 Kbit - same | 4 Kbit - same | 4 Kbit - same |
| Memory Organization | 16 pages x 32 bytes | 16 pages x 32 bytes - same | 16 pages x 32 bytes - same | 16 pages x 32 bytes - same | 16 pages x 32 bytes - same |
| Interface | 1-Wire (single-conductor) | 1-Wire - same | 1-Wire - same | 1-Wire - same | 1-Wire - same |
| Operating Voltage | 2.8 V to 5.25 V | 2.8 V to 5.25 V - same | 2.8 V to 5.25 V - same | 2.8 V to 5.25 V - same | 2.8 V to 5.25 V - same |
| Write/Erase Endurance | 200K cycles per page | 200K cycles per page - same | 200K cycles per page - same | 200K cycles per page - same | 200K cycles per page - same |
| Unique ROM Registration | 64-bit factory-programmed | 64-bit - same | 64-bit - same | 64-bit - same | 64-bit - same |
| Operating Temperature | -40°C to +85°C | -40°C to +85°C - same | -40°C to +85°C - same | -40°C to +85°C - same | -40°C to +85°C - same |
| Mounting Type | Through-hole (TO-92) | Surface-mount (8-SOIC) - different | Through-hole (TO-92) - same | Through-hole (TO-92) - same | iButton probe contact - different |
Key Differentiators
- Single-conductor 1-Wire interface minimizes wiring complexity (vs I²C EEPROMs (e.g. M24C64))
- Unique factory-programmed 64-bit ROM registration (vs Standard I²C EEPROMs without unique IDs)
- 200K write/erase endurance per page (vs M24C64 I²C EEPROM (1M cycles))
- Software-compatible replacement for legacy DS2433 (vs DS2433+)
Design Notes
The DS24B33+ supports parasitic-power mode where the device draws operating current from the DQ line during read operations, eliminating the need for a dedicated VDD connection. In this mode, Pin 3 (VDD) must be tied to ground or left floating, and a strong pull-up (4.7 kΩ to VDD) on DQ must provide sufficient current during write/erase cycles. For write/erase, a strong pull-up is required for at least 10 ms while the EEPROM page commits; failure to provide adequate current results in write corruption.
Place a 4.7 kΩ pull-up resistor on the DQ line to ensure adequate signal high time during communication. For long cable runs (>3 m), use lower pull-up values (2.2 kΩ) to compensate for cable capacitance. Add an ESD protection diode (such as PESD5V0L1BA) on the DQ line near the connector to protect the DS24B33+ from electrostatic discharge events common in field-deployed applications. Keep DQ trace length under 30 cm for reliable 15.4 kbps standard-speed 1-Wire communication.
Do not exceed the maximum DQ line voltage of 5.25 V; the DS24B33+ is not 5V-tolerant on DQ when VDD is below 3.0 V. Always read the scratchpad before writing to EEPROM - writing without scratchpad verification corrupts the target page and requires re-initialization. The 64-bit ROM registration is factory-programmed and cannot be modified, so do not attempt to write to ROM addresses 0x0000-0x0007. For multidrop buses, ensure the host issues a Reset pulse and Presence pulse sequence before each transaction to wake all devices.
Estimated: At 15.4 kbps standard 1-Wire speed with 10 m of unshielded cable, total bus capacitance may reach 800-1000 pF, requiring a stronger pull-up (1 kΩ) for clean edges. The DS24B33+ output drive is open-drain, so the host must provide all sourcing current during read. Add a 100 Ω resistor in series with the DQ line near the host to dampen ringing on long cables. For overdrive speed (142 kbps), keep total cable length under 1 m to avoid signal integrity issues. CRC-16 verification at the end of each block read catches transmission errors introduced by EMI on industrial sites.
Compliance Information
RoHS compliant per Analog Devices product page. Not AEC-Q100 qualified; choose automotive-grade 1-Wire EEPROMs (e.g. DS28E15Q+) for automotive applications. Halogen-free status not specified in available data.
