Atmel Integrated Circuit Ic Serial Eeprom AT25010AN-10SU-2.7 SOP8 AT25010AN10SU2.7 AT25O1OAN-1OSU-2.7 SOP-8

AT25010AN-10SU-2.7 | SPI Serial EEPROM 1Kbit — 128×8, SOIC-8, 2.7–5.5V, Industrial Temperature

Part Number: AT25010AN-10SU-2.7

Manufacturer: Atmel Corporation (now Microchip Technology)

Product Type: SPI Serial EEPROM

Capacity: 1Kbit (128 × 8 organisation)

Interface: 3-Wire SPI (Modes 0 and 3 compatible)

Package: SOIC-8 (8-pin Small Outline IC)

Mounting: SMD/SMT

Supply Voltage: 2.7V – 5.5V

Max Clock Frequency: 10 MHz

Access Time: 40 ns

Temperature Range: −40°C to +85°C (Industrial)

Compliance: RoHS / Green (halogen-free)

Overview

The AT25010AN-10SU-2.7 is a 1Kbit SPI serial EEPROM from Atmel's AT25 series — one of the most widely used serial EEPROM families in embedded systems design. It organises 1024 bits as 128 bytes, each byte individually addressable over the SPI bus.

The 2.7V minimum supply specification makes it compatible with both 3.3V and 5V power domains without level shifting, which is the practical advantage this specific variant offers in mixed-voltage board designs.

EEPROM (Electrically Erasable Programmable Read-Only Memory) is the right choice wherever a design needs to store small amounts of data that must survive power cycling but requires occasional updates over the product's life.

Configuration parameters, calibration values, product serial numbers, usage counters, and feature unlock flags are all typical EEPROM applications.

The AT25010AN-10SU-2.7 provides 128 bytes of this persistent writable storage in the compact SOIC-8 footprint that fits easily on boards from the smallest sensor modules to larger industrial controllers.

The part's industrial temperature rating — operation from −40°C to +85°C — reflects Atmel's design intent for this variant.

Consumer electronics EEPROM variants typically cover only 0°C to +70°C.

The N grade in this part number specifically denotes the industrial temperature range, making it appropriate for applications exposed to temperature extremes in outdoor installations, machine tool cabinets, and automotive-adjacent environments.

Key Specifications

SPI Interface — Simple, Fast, Widely Supported

The AT25010AN-10SU-2.7 uses the SPI (Serial Peripheral Interface) bus. SPI is a four-wire synchronous serial interface — Clock (SCK), Master Out Slave In (MOSI), Master In Slave Out (MISO), and Chip Select (CS).

The EEPROM is a passive device on this bus; the host microcontroller drives the clock and initiates all transactions.

The AT25010AN supports both SPI Mode 0 (CPOL=0, CPHA=0) and Mode 3 (CPOL=1, CPHA=1).

These two modes differ in clock polarity and phase. Most microcontroller SPI peripherals support both modes, so the AT25010AN is compatible with virtually any MCU with an SPI peripheral, regardless of how that peripheral's default mode is configured.

At 10 MHz, a full byte read takes less than 1 microsecond.

A complete read of all 128 bytes takes around 120 microseconds — fast enough for applications that read configuration data at startup without adding perceptible delay to system boot time.

Write Operations — Page Mode and Self-Timed Cycle

Write operations to EEPROM require an internal programming cycle where the charge on the floating-gate transistors is adjusted to represent the new data. The AT25010AN uses an 8-byte page structure.

Within a single write command, up to 8 bytes within the same page can be written simultaneously, and the internal programming cycle handles all of them together.

Writing data that spans multiple pages requires separate write commands with the TWC (Write Cycle Time) interval between them.

The write cycle is self-timed — the device manages its own internal programming without requiring the host to supply a clock during the cycle.

The host can poll the device's Ready/Busy status to determine when the cycle is complete before issuing the next write.

The maximum TWC time is 10ms. For applications that write rarely, this latency is inconsequential.

For applications that write frequently, careful management of write timing and page boundaries optimises throughput.

SOIC-8 Package and Assembly Considerations

The SOIC-8 (Small Outline Integrated Circuit, 8 pins) is a well-established SMD package with 1.27mm pin pitch — wider than TSSOP and other fine-pitch alternatives.

The AT25010AN-10SU-2.7's SOIC-8 package can be assembled by standard pick-and-place equipment and soldered by reflow, wave, or hand-iron depending on the manufacturing process. 

The wider pitch also makes it accessible for rework and repair on assembled boards.

The "SU" suffix in the part number confirms the green (RoHS and halogen-free) SOIC-8 package.

This suffix also indicates the lead-free finish, making the part compatible with lead-free solder processes that are now standard in most electronics manufacturing.

FAQ

Q1: The AT25010AN-10SU-2.7 is specified for 2.7V to 5.5V. Can it be used on a 3.3V system without any voltage level conversion?

Yes. The 2.7V to 5.5V supply range makes the AT25010AN-10SU-2.7 directly compatible with both 3.3V and 5V systems.

The SPI bus signals — SCK, MOSI, MISO, CS — can operate at 3.3V levels with no level conversion required when the VCC is 3.3V. 

For a 5V VCC with a 3.3V host MCU, check whether the MCU's SPI input pins are 5V-tolerant before connecting directly, as the EEPROM's output high level will be close to 5V.

Q2: The system reads back incorrect data from the EEPROM after a write operation. The write appeared to complete successfully. What could be wrong?

The most common cause is insufficient delay between completing the write command and issuing the read. The EEPROM requires the full internal write cycle to complete before the new data is accessible.

If the host issues a read too soon after a write, it may receive the old data. Implement a status register poll (checking the Write In Progress bit) or add a fixed delay of at least 10ms after each write before reading back to verify data integrity.

Q3: The EEPROM occasionally reads back corrupted data after the system has been in use for several months. What should be investigated?

Intermittent readback corruption points to write cycle management issues or power supply instability during writes.

If a write cycle is interrupted by a power interruption, the affected page may be partially written, leaving data in an unpredictable state. 

Implement Write Enable and Write Protect management carefully in firmware.

Also check the power supply for glitches — decoupling the EEPROM's VCC pin with a 100nF ceramic capacitor placed as close as possible to the VCC pin reduces power supply noise sensitivity.

Q4: This is a 1Kbit EEPROM. The design requires 256 bytes. Is there a pin-compatible Atmel equivalent with more capacity?

Yes. Atmel's AT25020A (2Kbit / 256×8) and AT25040A (4Kbit / 512×8) are pin-compatible with the AT25010AN in the same SOIC-8 package, using the same SPI interface and command structure.

The firmware addressing must account for the different memory organisation. 

The 2Kbit and 4Kbit variants have the same overall form factor and voltage range, so the PCB footprint does not need to change.

Q5: The part is now supplied by Microchip. Is the Microchip version identical to the original Atmel version?

Microchip acquired Atmel in 2016 and continued the AT25 EEPROM product family.

The AT25010AN-10SU-2.7 supplied by Microchip maintains the same electrical specifications, pinout, and SPI protocol as the original Atmel version. 

Datasheets are available from Microchip's website. 

For critical applications, verify the specific revision of the datasheet against the requirements to confirm no application-relevant specification changes were introduced.