Microchip Technology 25LC128T-E/ST16KVAO

Overview

25LC128T-E/ST16KVAO from Microchip Technology Inc. is a 128 Kbit SPI Serial EEPROM with 16,384 × 8-bit organization, 64-byte page size, and AEC-Q100 qualified extended temperature operation (–40°C to +125°C). It supports up to 10 MHz clock 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 years data retention - used in automotive body control modules for storing calibration and configuration data.

For engineers reviewing the 25LC128T-E/ST16KVAO datasheet, 25LC128T-E/ST16KVAO pinout, 25LC128T-E/ST16KVAO application, or 25LC128T-E/ST16KVAO equivalent, this page provides verified electrical specs, SPI timing constraints, HOLD/CS/WP functional behavior, package-specific pin mapping for TSSOP-8, and real-world design implications of block protection and page-write boundary handling.

Technical Context

The 25LC128T-E/ST16KVAO implements a standard SPI Mode 0,0 (CPOL=0, CPHA=0) interface with separate SI/SO lines and active-low CS. It uses an internal high-voltage generator for EEPROM programming and includes a dedicated HOLD input to suspend ongoing transfers without resetting the sequence.

Its STATUS register contains WIP (Write-In-Process), WEL (Write Enable Latch), BP0/BP1 (block protection bits), and WPEN (Write-Protect Enable), enabling flexible, nonvolatile memory protection schemes. Write operations require explicit WREN instruction and CS rising-edge initiation, with self-timed internal write cycles completing in ≤5 ms.

Key Specifications

Pinout & Package

25LC128T-E/ST16KVAO is packaged in an 8-lead TSSOP (Thin Shrink Small Outline Package) with 0.65 mm pitch, JEDEC MO-153 compliant, and marked "25LC128I" on top (I = Industrial temp code per marking convention; full part number encoded in reel label per DS20001831F-page 14).

Key Features

Applications

Equivalent & Alternatives

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

Compared with 25AA128T-I/ST and AT25DF041A-SSH-T, the 25LC128T-E/ST16KVAO uniquely combines AEC-Q100 qualification, 2.5–5.5 V operation, HOLD functionality, and pin-compatible TSSOP-8 packaging - making it the only option among the three suitable for extended-temperature automotive EEPROM tasks without layout or firmware changes.

Availability

25LC128T-E/ST16KVAO is available at Aetrix Electronics and suitable for automotive body control units, industrial PLCs, medical infusion pumps, and smart energy meters requiring stable component supply across extended temperature ranges and long product lifecycles.

Supply support for 25LC128T-E/ST16KVAO 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 design, manufacturing, and sales operations.

The 25LC128T-E/ST16KVAO belongs to Microchip's 25XX128 family of SPI Serial EEPROMs, designed specifically for automotive and industrial applications demanding high reliability, extended temperature operation, and robust data integrity under electrical stress.

FAQ

What is the maximum clock frequency supported by the 25LC128T-E/ST16KVAO, and how does voltage affect it?

The 25LC128T-E/ST16KVAO supports up to 10 MHz at VCC ≥ 4.5 V, 5 MHz at 2.5 V ≤ VCC < 4.5 V, and is not rated for operation below 2.5 V. These limits are defined in Table 1-2 AC Characteristics and reflect guaranteed timing margins - exceeding them risks setup/hold violations and data corruption. The 25LC128T-E/ST16KVAO must never be operated above 10 MHz, even at 5.5 V.

Does the 25LC128T-E/ST16KVAO support page writes, and what happens if a write crosses a page boundary?

Yes, the 25LC128T-E/ST16KVAO supports page writes of up to 64 bytes, but only within a single physical page (addresses 0000h–003Fh, 0040h–007Fh, etc.). If a page write command attempts to cross a boundary - e.g., writing 64 bytes starting at address 003Ch - the excess bytes wrap to the start of the same page (0000h), overwriting prior data. This behavior is explicitly documented in DS20001831F-page 7 and applies to all 25LC128T-E/ST16KVAO units.

How does the HOLD pin function on the 25LC128T-E/ST16KVAO, and what are its timing requirements?

The HOLD pin on the 25LC128T-E/ST16KVAO pauses ongoing SPI communication without resetting the sequence. To invoke HOLD, the pin must be pulled low while SCK is low; to resume, it must be raised high while SCK remains low. During HOLD, SO/SI/SCK enter high-Z state and ignore transitions. Minimum HOLD setup/hold times are 20 ns (VCC ≥ 4.5 V), per Table 1-2 param #16–17 - violating these invalidates the hold action.

Is the 25LC128T-E/ST16KVAO AEC-Q100 qualified, and which stress test grades does it meet?

Yes, the 25LC128T-E/ST16KVAO is AEC-Q100 qualified for Extended temperature grade (–40°C to +125°C), as confirmed in the Device Selection Table on DS20001831F-page 1. It meets stress test requirements for accelerated environmental stress, including temperature cycling, humidity bias, and ESD (≥4 kV HBM), per AEC-Q100 Rev G. This qualification is specific to the 25LC128T-E/ST16KVAO variant and not inherited from other 25XX128 family members.

What is the purpose of the WPEN bit in the STATUS register of the 25LC128T-E/ST16KVAO?

The WPEN (Write-Protect Enable) bit (SR bit 7) controls whether the WP pin actively blocks STATUS register writes. When WPEN = 1 and WP = low, writes to nonvolatile STATUS bits (BP0/BP1/WPEN) are disabled - protecting critical protection settings. When WPEN = 0, the WP pin has no effect, allowing full STATUS register access regardless of WP state. This dual-layer control is essential for field-upgrade safety in the 25LC128T-E/ST16KVAO.