Microchip Technology 25LC128-E/SN16KVAO

Overview

25LC128-E/SN16KVAO from Microchip Technology Inc. is a 128 Kbit SPI Serial EEPROM with 16,384 × 8-bit organization, 64-byte page size, and extended temperature operation from –40°C to +125°C. It supports up to 10 MHz clock frequency at 4.5–5.5 V, features hardware write protection via WP pin and STATUS register, and delivers 1,000,000 erase/write cycles with >200-year data retention - used in automotive engine control units for calibration storage.

For engineers reviewing the 25LC128-E/SN16KVAO datasheet, 25LC128-E/SN16KVAO pinout, 25LC128-E/SN16KVAO application, or 25LC128-E/SN16KVAO equivalent, key selection considerations include its extended-temp SOIC-8 (SN) package, 2.5–5.5 V supply range, block-level write protection (BP0/BP1), HOLD functionality for interrupt-safe SPI pauses, and AEC-Q100 qualification for automotive use.

Technical Context

The 25LC128-E/SN16KVAO implements a standard SPI Mode 0,0 interface with separate SI (data-in) and SO (data-out) lines, requiring CS, SCK, and optional HOLD/WP control. Its internal architecture includes a 64-byte page latch, HV generator for EEPROM programming, and status register with WIP, WEL, BP0/BP1, and WPEN bits.

Write operations require explicit WREN instruction before WRITE or WRSR; CS high after final data bit initiates self-timed internal write cycle (≤5 ms). HOLD suspends ongoing transfers without resetting state, and WP pin enables hardware-based protection when WPEN=1 - both critical for deterministic behavior in safety-critical automotive firmware updates.

Key Specifications

Pinout & Package

25LC128-E/SN16KVAO uses an 8-lead narrow SOIC package (SN), 3.90 mm body width, with standard JEDEC MS-012AC footprint. Pin 1 is marked by beveled corner or notch; exposed pad is absent (unlike DFN variants).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar serial EEPROM applications.

Compared with 25LC128-E/SN16KVAO, the 25AA128-I/SN offers broader voltage flexibility but lacks extended-temp validation, while the AT25DF041A-SHN-T provides greater capacity and speed at the cost of compatibility, protection features, and automotive compliance - making 25LC128-E/SN16KVAO optimal for safety-critical, thermally demanding, and protection-sensitive deployments.

Availability

25LC128-E/SN16KVAO is available at Aetrix Electronics and suitable for automotive ECU development, industrial PLC configuration, medical infusion pump calibration, and smart energy meter firmware patching requiring stable component supply across extended temperature ranges and long product lifecycles.

Supply support for 25LC128-E/SN16KVAO includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Microchip Technology Inc. is a leading provider of microcontrollers, analog devices, and memory solutions, headquartered in Chandler, Arizona, with global manufacturing and support infrastructure.

The 25LC128-E/SN16KVAO belongs to Microchip's 25XX128 family of SPI EEPROMs, designed specifically for reliable, low-power, and AEC-Q100-compliant nonvolatile storage in automotive, industrial, and medical systems requiring deterministic write behavior and long-term data integrity.

FAQ

What is the maximum clock frequency supported by the 25LC128-E/SN16KVAO?

The 25LC128-E/SN16KVAO supports up to 10 MHz clock frequency when VCC is between 4.5 V and 5.5 V. At lower voltages (2.5–4.4 V), the maximum clock drops to 5 MHz, and at 1.8–2.4 V it would be 3 MHz - though 25LC128-E/SN16KVAO's minimum VCC is 2.5 V, so 5 MHz is its guaranteed lower bound. This ensures timing compliance across its specified operating range without external clock dividers.

Does the 25LC128-E/SN16KVAO require external pull-up resistors on its SPI lines?

No, the 25LC128-E/SN16KVAO does not require external pull-ups on SI, SO, or SCK - these pins are CMOS-compatible with internal weak pull-downs on inputs (CS, WP, HOLD) and actively driven outputs (SO). However, CS should be pulled high via a 10 kΩ resistor in systems with shared SPI buses to prevent unintended selection during reset, and WP may be pulled low externally to enforce hardware protection.

How does the HOLD function operate in the 25LC128-E/SN16KVAO during an ongoing read sequence?

When HOLD is asserted low during an active read sequence, the 25LC128-E/SN16KVAO immediately places SO in high-impedance state and ignores further SCK transitions, preserving the internal address pointer and shift register state. Communication resumes from the exact byte position once HOLD returns high while SCK is low - enabling the host MCU to service time-critical interrupts without retransmitting the entire command/address sequence.

Can the 25LC128-E/SN16KVAO be used as a direct replacement for the 25AA128-I/SN in an existing design?

The 25LC128-E/SN16KVAO is pin-compatible and functionally identical to the 25AA128-I/SN in instruction set, timing, and pinout, but differs in supply voltage (2.5–5.5 V vs. 1.8–5.5 V) and temperature grade (–40°C to +125°C vs. –40°C to +85°C). It can replace 25AA128-I/SN only if the system operates ≥2.5 V and requires extended temperature capability - verify WPEN default state and update qualification documentation accordingly.

What happens to the write enable latch after a successful write operation completes on the 25LC128-E/SN16KVAO?

After a successful WRITE, WRSR, or WRDI instruction completes, the write enable latch (WEL bit) in the 25LC128-E/SN16KVAO is automatically reset to '0'. This means the device reverts to write-disabled state, requiring an explicit WREN instruction before any subsequent write - a safety feature preventing accidental overwrites due to noise or software errors. Power-up also resets WEL, ensuring known initial state.