Microchip Technology 25LC160AT-E/ST

Overview

25LC160AT-E/ST from Microchip Technology Inc. is a 16 Kbit (2048 × 8) SPI Serial EEPROM with 16-byte page size, 2.5–5.5 V supply range, and industrial/automotive temperature rating (–40°C to +125°C). It features hardware write protection via WP pin, HOLD functionality for bus arbitration, and self-timed 5 ms max write cycles. It serves as nonvolatile configuration storage in automotive body control modules requiring AEC-Q100-aligned reliability.

For engineers reviewing the 25LC160AT-E/ST datasheet, 25LC160AT-E/ST pinout, 25LC160AT-E/ST application, or 25LC160AT-E/ST equivalent, key selection criteria include its 16-byte page write limit, –40°C to +125°C operation, TSSOP-8 package compatibility, and SPI Mode 0,0/1,1 support with CS/SCK/SI/SO/HOLD/CS/WP/VSS/VCC interface.

Technical Context

The 25LC160AT-E/ST implements a standard SPI-compatible serial interface with separate SI (data-in) and SO (data-out) lines, supporting clock frequencies up to 10 MHz at 4.5–5.5 V. Its internal architecture includes an 8-bit instruction register, page latches, and HV generator for EEPROM programming.

It uses a two-stage write sequence: WREN instruction must be issued and latched before WRITE, and CS must go high after final data bit to trigger the internal 5 ms write cycle. Block protection is configurable via BP0/BP1 bits to protect 0%, 25%, 50%, or 100% of the 0000h–07FFh address space.

Key Specifications

Pinout & Package

25LC160AT-E/ST is packaged in an 8-lead TSSOP (Thin Shrink Small Outline Package) with 0.65 mm lead pitch, JEDEC MO-153 compliant, and Pb-free/RoHS-compliant marking.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 25LC160AT-E/ST, the 25LC160BT-E/ST offers double the page buffer but demands updated page-boundary handling in firmware, while AT25DF021-SSH-T trades configurability and robustness for density and speed - making 25LC160AT-E/ST optimal for safety-critical, low-density, interrupt-aware automotive storage.

Availability

25LC160AT-E/ST 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 25LC160AT-E/ST 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 microcontroller, analog, and Flash-IP solutions, headquartered in Chandler, Arizona, with global design and manufacturing operations.

The 25LC160A/B family was designed specifically for robust, low-power, SPI-based nonvolatile storage in automotive and industrial environments where data integrity, endurance, and extended temperature operation are critical.

FAQ

What is the page size of the 25LC160AT-E/ST and why does it matter for firmware design?

The 25LC160AT-E/ST has a fixed 16-byte page size. This means up to 16 consecutive bytes can be written in a single page-write command, but crossing a 16-byte boundary causes wraparound within the same page - overwriting earlier data. Firmware must align writes to 16-byte boundaries and check address offsets before initiating page writes to avoid corruption. This constraint directly impacts how configuration blocks or parameter sets are structured in memory.

Does the 25LC160AT-E/ST support both SPI Mode 0,0 and Mode 1,1, and how is mode selection handled?

Yes, the 25LC160AT-E/ST supports both SPI Mode 0,0 (CPOL = 0, CPHA = 0) and Mode 1,1 (CPOL = 1, CPHA = 1) as defined in the datasheet timing diagrams. Mode selection is determined solely by the host MCU's SPI peripheral configuration - no internal register setting or command is required. The device samples SI on the rising edge and drives SO after the falling edge in both modes, ensuring interoperability with diverse microcontrollers including PIC®, AVR, and ARM Cortex-M families.

How does hardware write protection work on the 25LC160AT-E/ST, and what happens when WP is pulled low?

Hardware write protection on the 25LC160AT-E/ST requires both the WP pin to be low AND the WPEN bit (bit 7 of STATUS register) to be set to 1. When both conditions are met, writes to the nonvolatile STATUS register bits (BP0, BP1, WPEN) are blocked - preventing accidental changes to protection settings. Memory array writes remain fully functional. If WPEN = 0, the WP pin is ignored entirely, allowing full STATUS register access even with WP grounded - a key design flexibility for field-programmable systems.

What is the purpose of the HOLD pin on the 25LC160AT-E/ST, and what timing constraints apply?

The HOLD pin on the 25LC160AT-E/ST pauses ongoing SPI communication without resetting the internal state - enabling the host MCU to service urgent interrupts and resume exactly where it left off. To activate HOLD, the pin must be driven low while SCK is low; asserting HOLD during SCK high delays activation until the next SCK falling edge. Resuming requires bringing HOLD high while SCK is low. During HOLD, SI, SO, and SCK enter high-impedance states, and SO is tri-stated.

Is the 25LC160AT-E/ST qualified for automotive applications, and what evidence supports this claim?

Yes, the 25LC160AT-E/ST is qualified for automotive use. Its "E" suffix denotes the Automotive temperature grade (–40°C to +125°C), and the "T-E/ST" package variant is explicitly listed in Microchip's DS21807D datasheet as rated for Automotive operation. The device meets AEC-Q100 stress testing requirements for temperature cycling, HTSL, and ESD (>4 kV HBM), and its 1M endurance and >200-year data retention are validated for automotive ECU lifetimes exceeding 15 years.