Microchip Technology 25AA160B-I/ST

Overview

25AA160B-I/ST from Microchip Technology Inc. is a 16 Kbit (2048 × 8) SPI Serial EEPROM with 32-byte page write capability, 1.8–5.5 V supply range, and industrial temperature rating (–40°C to +85°C). It features hardware write protection via WP pin and STATUS register, HOLD functionality for bus arbitration, and self-timed 5 ms max write cycles. Used in embedded systems for firmware storage, calibration data retention, and configuration parameter backup.

For engineers reviewing the 25AA160B-I/ST datasheet, 25AA160B-I/ST pinout, 25AA160B-I/ST application, or 25AA160B-I/ST equivalent, key selection criteria include page size (32 B), VCC min (1.8 V), endurance (1M cycles), data retention (>200 years), and TSSOP-8 package compatibility with space-constrained PCB layouts.

Technical Context

The 25AA160B-I/ST implements a standard SPI Mode 0,0/Master-Slave interface with separate SI (data in) and SO (data out) lines, requiring CS, SCK, and optional HOLD/WP control. Its internal architecture includes an 8-bit instruction register, page latches, and high-voltage generator for EEPROM programming.

Write operations require explicit WREN instruction followed by WRITE command and address; page writes are limited to 32 bytes within a single physical page boundary (0000h–001Fh, 0020h–003Fh, etc.). The STATUS register provides real-time WIP flag polling and configurable block protection (BP1/BP0) for 0%, 25%, 50%, or 100% array write-lock.

Key Specifications

Pinout & Package

25AA160B-I/ST is packaged in an 8-lead TSSOP (Thin Shrink Small Outline Package) with 0.65 mm lead pitch, optimized for automated assembly and compact board layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 25AA160B-I/ST, the 25LC160B-I/ST offers identical functionality at higher VCC minimum, while the AT25160B-SSHL-T sacrifices HOLD and STATUS register compatibility for Atmel-compatible firmware ecosystems - both require validation of voltage margin and interrupt handling impact.

Availability

25AA160B-I/ST is available at Aetrix Electronics and suitable for industrial automation, medical diagnostics, and automotive body electronics requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant packaging.

Supply support for 25AA160B-I/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 microcontrollers, analog devices, and memory solutions, headquartered in Chandler, Arizona, with global design and manufacturing operations.

The 25AA160B-I/ST belongs to Microchip's 25XX160 family of SPI EEPROMs, designed specifically for reliable, low-voltage, high-endurance nonvolatile storage in resource-constrained embedded systems.

FAQ

What is the minimum supply voltage required for reliable operation of the 25AA160B-I/ST?

The 25AA160B-I/ST operates reliably down to 1.8 V across its full industrial temperature range (–40°C to +85°C). Below this threshold, DC characteristics such as VIH/VIL and AC timing parameters (e.g., FCLK max = 3 MHz at 1.8 V) degrade, and write operations may fail. Always verify VCC stability under load using the 1 µF decoupling capacitor specified in the datasheet.

How does the HOLD pin function during an active SPI transaction on the 25AA160B-I/ST?

When the HOLD pin is pulled low while SCK is low, the 25AA160B-I/ST immediately suspends SPI communication, tri-states SO, and ignores further transitions on SI/SCK until HOLD returns high - also while SCK is low. This preserves the internal state (e.g., address pointer, instruction phase) so the host can service interrupts and resume exactly where it left off, without retransmitting commands or addresses.

Can the 25AA160B-I/ST be used for page writes that cross physical page boundaries?

No. Page writes on the 25AA160B-I/ST are strictly confined to a single 32-byte physical page (e.g., 0000h–001Fh). Attempting to write across a boundary causes data to wrap around to the start of the same page, overwriting previously loaded bytes. Application firmware must explicitly check address alignment and split writes at page boundaries - a requirement enforced by the device's internal page latch architecture.

What protection mechanisms prevent accidental writes to the 25AA160B-I/ST memory array?

The 25AA160B-I/ST employs three layered protections: (1) a volatile write-enable latch reset on power-up and after every successful write, (2) nonvolatile block protection bits (BP1/BP0) configurable via WRSR to lock 0–100% of memory, and (3) hardware write protection enabled only when both WP pin is low AND WPEN bit is set - all working independently to ensure robust data integrity.

Is the 25AA160B-I/ST compatible with standard SPI Mode 0,0 interfaces?

Yes. The 25AA160B-I/ST fully complies with SPI Mode 0,0 (CPOL = 0, CPHA = 0): data is sampled on the rising edge of SCK and shifted out on the falling edge. It supports standard SPI instruction set (READ, WRITE, WREN, RDSR, etc.) with MSB-first transmission, making it interoperable with PIC®, ARM Cortex-M, and other microcontrollers featuring native SPI peripherals.