24LC01B-I/SN Selection Guide: How to Choose the Right Microchip I2C EEPROM Variant
Compare 24LC01B-I/SN, MSOP-8, SOT-23-5, and other Microchip 1 Kbit I2C EEPROM variants. Pick the right package, temp grade, and stocking option for your design.
Last updated: May 2026
Bottom Line: When choosing a Microchip 24LC01B-series I2C EEPROM, the three most important considerations are package format (SOIC-8, MSOP-8, SOT-23-5, or PDIP-8), operating voltage range (2.5 V–5.5 V for standard variants), and write-endurance rating (1,000,000 cycles minimum for most applications). The 24LC01B-I/SN in an SOIC-8 package is the most widely stocked variant and is the safest default for new designs targeting 3.3 V or 5 V systems.
Overview: The 24LC01B Family
The Microchip 24LC01B is a 1 Kbit (128 × 8 bytes) I2C serial EEPROM designed for low-power, cost-sensitive embedded applications. It communicates over a two-wire I2C bus at up to 400 kHz (Fast Mode), making it compatible with virtually every modern microcontroller. The family shares the same register map and electrical interface across all package variants, so engineers can swap footprints without firmware changes.
All 24LC01B variants offer a voltage range of 2.5 V to 5.5 V, a write cycle time of 5 ms maximum, and a data retention specification of 200 years at 25 °C. These characteristics make the part suitable for storing calibration constants, configuration parameters, and serial number data in consumer electronics, industrial sensors, and IoT edge nodes.
The family members covered in this guide are:
- 24LC01B-I/SN — SOIC-8 (standard production workhorse)
- 24LC01B-I/MS — MSOP-8 (smaller footprint)
- 24LC01BT-I/OT — SOT-23-5 (ultra-compact)
- 24LC01B/SN — SOIC-8 (industrial temp alternative)
Selection Parameter 1: Package Type
Package selection is often the first hard constraint in a new design, driven by PCB area budget and pick-and-place capability. The 24LC01B family ships in four standard packages:
| Package | Footprint Area | Pitch | Typical Use Case |
|---|---|---|---|
| SOIC-8 (SN suffix) | 5.0 × 4.0 mm | 1.27 mm | General SMT production |
| MSOP-8 (MS suffix) | 3.0 × 3.0 mm | 0.65 mm | Space-constrained SMT |
| SOT-23-5 (OT suffix) | 2.9 × 1.6 mm | 0.95 mm | Ultra-compact wearables |
| PDIP-8 (P suffix) | Through-hole | 2.54 mm | Prototyping, hobby |
For high-volume automated assembly, the SOIC-8 (24LC01B-I/SN) offers the best combination of hand-rework accessibility and tape-and-reel availability. The MSOP-8 (24LC01B-I/MS) saves roughly 56% board area and is preferred for wearables or dense IoT modules. The SOT-23-5 (24LC01BT-I/OT) is only 5-pin: A0, SDA, SCL, GND, VCC — it sacrifices the WP (write-protect) pin present on 8-pin packages, which is acceptable when hardware write-protection is not needed.
Selection Parameter 2: Operating Voltage and I/O Logic Levels
All 24LC01B variants support VCC from 2.5 V to 5.5 V, making them inherently compatible with both 3.3 V and 5 V systems without level-shifting hardware. The I2C SDA and SCL pins are open-drain, so the pull-up voltage determines the logic high level independently of VCC. A typical design uses 4.7 kΩ pull-ups to VCC for 100 kHz operation, or 2.2 kΩ for 400 kHz Fast Mode.
For ultra-low-voltage applications (e.g., a CR2032-powered sensor node), note that at VCC = 2.5 V the maximum bus speed drops to 400 kHz and the write cycle time remains 5 ms. There is no sub-2.5 V variant in the 24LC01B family; for 1.8 V systems, consider the Microchip 24AA01 (not covered here). At 5 V, the standby current is typically 1 µA maximum — negligible for always-on designs.
Selection Parameter 3: Write Endurance and Data Retention
Endurance is the dominant reliability factor for EEPROM in applications with frequent writes. The 24LC01B is rated at 1,000,000 erase/write cycles per byte, compliant with JEDEC standard JESD47. Data retention is 200 years at 25 °C, dropping to approximately 50 years at 55 °C — both well above the 10-year product lifetime common in industrial equipment.
For applications with update rates above ~30 writes per day across 10 years (roughly 110,000 cycles), the 1M cycle endurance provides a comfortable 9× margin. If your application writes a timestamp every second (86,400 cycles/day), the 24LC01B's 1 Kbit capacity is likely too small anyway, and a larger EEPROM or FRAM should be evaluated.
Selection Parameter 4: Temperature Grade
The suffix letter immediately after the package code denotes the temperature grade. -I indicates Industrial grade: –40 °C to +85 °C. Variants without a grade suffix (e.g., 24LC01B/SN) cover the commercial range of 0 °C to +70 °C.
For automotive or harsh industrial environments requiring AEC-Q100 qualification, the 24LC01B is not the appropriate choice — consult Microchip's automotive EEPROM portfolio (24AA/24LC AEC-Q100 variants). For all standard industrial IoT and consumer designs, the -I grade variants cover the required range with margin.
Selection Parameter 5: Bus Speed
All 24LC01B package variants support 100 kHz Standard Mode and 400 kHz Fast Mode I2C. There is no I2C High-Speed (3.4 MHz) or SMBus variant in this family. For applications requiring faster access (e.g., live audio parameter updates), the 400 kHz limit means a full 128-byte sequential read completes in approximately 2.5 ms — sufficient for most embedded configuration storage tasks.
Write operations are limited by the internal programming cycle: 5 ms maximum per write, regardless of bus speed. Page write mode allows up to 8 bytes per cycle, reducing total write time for bulk updates by up to 8×. Ensure your firmware uses sequential page writes, not byte-by-byte writes, to stay within timing budgets.
Selection Parameter 6: Supply Chain and Stocking Depth
Stocking depth across global distributors is a practical selection criterion that engineers often overlook at the design phase. SOIC-8 variants (24LC01B-I/SN) consistently show the deepest distributor coverage, with authorized stocking at Microchip Direct, DigiKey, Mouser, and dozens of regional distributors in Asia and Europe. MSOP-8 and SOT-23-5 variants carry narrower stocking but are still catalogued parts with lead times under 12 weeks from Microchip.
For BOM risk management, consider qualifying the SOIC-8 as primary and MSOP-8 as alternate — both are footprint-incompatible on the PCB but pin-compatible in firmware. Cross-quote both variants together on FindMyChip's /quote page to lock in competitive pricing from 200+ verified distributors. You can also search for all 24LC01B variants to compare live pricing and availability.
Recommended Products Comparison Table
| Product | Package | Temp Grade | Bus Speed | WP Pin | Best For |
|---|---|---|---|---|---|
| 24LC01B-I/SN | SOIC-8 | –40 to +85 °C | 400 kHz | Yes | General SMT production, easiest rework |
| 24LC01B-I/MS | MSOP-8 | –40 to +85 °C | 400 kHz | Yes | Space-constrained industrial designs |
| 24LC01BT-I/OT | SOT-23-5 | –40 to +85 °C | 400 kHz | No | Ultra-compact wearables and IoT nodes |
| 24LC01B/SN | SOIC-8 | 0 to +70 °C | 400 kHz | Yes | Commercial temp, lower unit cost |
Price range: typically $0.15–$0.45 USD per unit at quantities of 100–10,000 pcs, depending on package and distributor.
Selection Decision Flowchart
Use this decision tree to narrow the right variant for your application:
- Do you need through-hole for prototyping? → Yes: use 24LC01B/P (PDIP-8). No: proceed.
- Is board area severely constrained (< 5 × 4 mm available)? → Yes: proceed to step 3. No: choose 24LC01B-I/SN (SOIC-8, –40 to +85 °C) or 24LC01B/SN (commercial temp).
- Do you need hardware write-protection (WP pin)? → Yes: choose 24LC01B-I/MS (MSOP-8). No: choose 24LC01BT-I/OT (SOT-23-5).
- Is operating temperature below –20 °C or above +60 °C? → If yes, confirm your variant has the
–Iindustrial grade suffix.
FAQ
Q: What is the difference between 24LC01B-I/SN and 24LC01B/SN?
The -I suffix denotes the industrial temperature grade (–40 °C to +85 °C), while the plain 24LC01B/SN covers commercial temperature (0 °C to +70 °C). Both are SOIC-8 packages with identical electrical specs. The industrial variant typically costs $0.02–$0.05 more per unit at moderate quantities. Choose the -I variant for any design expected to operate in uncontrolled outdoor or vehicle environments.
Q: Can I use the 24LC01B at 1.8 V? No. The 24LC01B minimum VCC is 2.5 V. For 1.8 V systems, Microchip offers the 24AA01 series (1.7 V minimum). Verify your MCU's I2C IO voltage compatibility before substituting — the 24LC01B SDA and SCL pins must not exceed VCC + 0.5 V.
Q: How many bytes can I write per I2C transaction? The 24LC01B supports a page size of 8 bytes. A single write transaction can include up to 8 data bytes after the device address and memory address bytes. Attempting to write more than 8 bytes in one transaction causes the internal address counter to wrap within the 8-byte page boundary, overwriting earlier bytes.
Q: Is the 24LC01B compatible with SMBus? Yes, for read operations. The 24LC01B's I2C interface is electrically compatible with SMBus 2.0 for most practical purposes, but the write cycle time (5 ms) exceeds the SMBus timeout specification (25 ms for some operations). Consult your host controller's SMBus timeout settings when using the device on an SMBus.
Q: What is the 24LC01B's address range on the I2C bus? The 24LC01B uses a 7-bit I2C address with the upper nibble fixed at 1010 (0xA). The lower three bits (A2, A1, A0) are hardware-configurable, but with only 128 bytes of address space, only A0 is internally meaningful. The device effectively supports up to 2 devices on a single I2C bus using A0 to differentiate them.
Conclusion
The 24LC01B-I/SN is the recommended default for most new designs: it offers industrial temperature coverage, the most widely supported SOIC-8 footprint, and the deepest global stocking. For space-constrained boards, move to the 24LC01B-I/MS (MSOP-8) or 24LC01BT-I/OT (SOT-23-5) while retaining identical firmware. Commercial-temperature designs can reduce BOM cost slightly with the 24LC01B/SN.
To compare live pricing and availability across 200+ verified distributors, search for 24LC01B variants on FindMyChip or submit a quote request for volume pricing with 24-hour response.