Microchip Technology 25AA160A-I/ST

Overview

25AA160A-I/ST from Microchip Technology Inc. is a 16 Kbit (2048 × 8) SPI Serial EEPROM with 1.8–5.5 V supply range, 16-byte page write capability, and industrial temperature rating (–40°C to +85°C). It features hardware write protection via WP pin and STATUS register, HOLD functionality for interrupt-safe bus suspension, and self-timed 5 ms max write cycles. Used in embedded systems for parameter storage, calibration data retention, and firmware configuration in microcontroller-based designs.

For engineers reviewing the 25AA160A-I/ST datasheet, 25AA160A-I/ST pinout, 25AA160A-I/ST application, or 25AA160A-I/ST equivalent, key selection criteria include V_CC compatibility down to 1.8 V, 16-byte page boundary constraints, WPEN-controlled hardware write protection, and TSSOP-8 package footprint suitability for space-constrained PCB layouts.

Technical Context

The 25AA160A-I/ST implements a standard SPI Mode 0,0/Multi-Master interface with separate SI and SO lines, requiring CS low, SCK edge-synchronized data transfer, and explicit WREN instruction before writes. Its internal architecture includes a status register with WIP, WEL, BP0/BP1, and WPEN bits controlling block protection and hardware lockout.

Write operations are page-limited (16 bytes), with automatic address rollover during sequential reads and high-impedance SO tri-state during HOLD assertion. Power-on defaults disable writes (WEL=0), enforce standby mode (CS=high), and initialize SO to high-Z - ensuring robust default safety against spurious writes.

Key Specifications

Pinout & Package

25AA160A-I/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 certified. The package measures 4.4 mm × 3.0 mm × 1.2 mm (max height), optimized for automated SMT assembly and thermal performance in compact enclosures.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 25AA160A-I/ST, the 25LC160A-I/ST offers identical functionality at higher V_CC minimum, while AT25160B-MAU-1.8 provides 1.8 V support but removes HOLD and alters protection semantics - making 25AA160A-I/ST the optimal choice for mixed-voltage systems requiring deterministic bus suspension and Microchip-ecosystem compatibility.

Availability

25AA160A-I/ST is available at Aetrix Electronics and suitable for industrial sensor calibration, medical device configuration, automotive body control modules, and smart energy meter firmware requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for 25AA160A-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 microcontroller, analog, and Flash-IP solutions, headquartered in Chandler, Arizona, with global design and manufacturing operations.

The 25AA160A-I/ST belongs to Microchip's 25XX160A/B family of SPI Serial EEPROMs, designed specifically for reliable, low-power, pin-efficient nonvolatile storage in resource-constrained embedded systems requiring industrial-grade reliability and flexible voltage operation.

FAQ

What is the maximum SPI clock frequency supported by the 25AA160A-I/ST?

The 25AA160A-I/ST supports up to 10 MHz SPI clock frequency when V_CC is 4.5–5.5 V, 5 MHz at 2.5–4.5 V, and 3 MHz at 1.8–2.5 V. These limits are defined in Table 1-2 AC Characteristics and ensure reliable setup/hold timing across voltage and temperature ranges. The 25AA160A-I/ST does not require external clock dividers or protocol adapters to operate at these rates.

How does the 25AA160A-I/ST handle page write boundaries during multi-byte programming?

The 25AA160A-I/ST restricts page writes to 16-byte boundaries (0x000–0x00F, 0x010–0x01F, etc.). If a page write command crosses a boundary, data wraps to the start of the current page instead of advancing to the next. This behavior is documented in Section 2.3 and requires firmware to split writes at page edges - a constraint inherent to the 25AA160A-I/ST's internal page latch architecture.

Can the 25AA160A-I/ST be used without connecting the HOLD pin?

Yes - the HOLD pin on the 25AA160A-I/ST is optional and may be left unconnected or tied high (V_CC) if bus suspension is not required. When unused, it must be held high to prevent unintended pausing; floating is not recommended. All other 25AA160A-I/ST functions operate normally with HOLD inactive.

What protection mechanisms prevent accidental writes to the 25AA160A-I/ST memory array?

The 25AA160A-I/ST employs four layered protections: (1) power-on reset clears the Write Enable Latch (WEL=0), (2) explicit WREN instruction required before any write, (3) hardware WP pin + WPEN bit combination locks STATUS register writes, and (4) CS must rise after final data bit to trigger internal write - all enforced in silicon per DS21807D Sections 2.4–2.7.

Is the 25AA160A-I/ST RoHS compliant and Pb-free?

Yes, the 25AA160A-I/ST is Pb-free and RoHS compliant per Microchip's DS21807D documentation (Section "Features" and Package Marking Information). The TSSOP-8 package carries the JEDEC Pb-free designation, and full compliance documentation is available in Microchip's official part declaration files.