Microchip Technology 25AA160/P

Overview

25AA160/P from Microchip Technology Inc. is a 16 Kbit (2048 × 8) SPI-compatible serial EEPROM with 1.8–5.5 V supply range, 1 MHz max clock frequency, and industrial temperature rating (−40°C to +85°C). It features 16-byte page write, hardware write protection via WP pin, and HOLD functionality for interrupt-safe bus suspension - deployed in embedded control systems requiring nonvolatile parameter storage.

For engineers reviewing the 25AA160/P datasheet, 25AA160/P pinout, 25AA160/P application, or 25AA160/P equivalent, key selection considerations include its 1.8 V minimum VCC operation, 5 ms max internal write cycle time, block-level write protection (0/¼/½/all array), and PDIP-8 package compatibility with legacy through-hole designs.

Technical Context

The 25AA160/P implements a standard SPI Mode 0,0 interface (CPOL=0, CPHA=0) with separate SI (data in, latched on SCK rising edge) and SO (data out, updated after SCK falling edge) lines. Chip Select (CS) enables device selection and initiates self-timed write cycles upon high transition after valid write sequence.

HOLD input suspends ongoing serial communication without resetting the internal address pointer or requiring retransmission; it requires assertion while SCK is low and resumes only when released during SCK low. Write enable latch (WEL) must be set via WREN instruction prior to any WRITE or WRSR command, and resets automatically after power-up, WRDI, or successful write completion.

Key Specifications

Pinout & Package

25AA160/P is supplied in an 8-pin Plastic Dual In-line Package (PDIP) with 300 mil body width, JEDEC MS-001 compliant footprint, and through-hole mounting. Lead finish is matte tin; RoHS-compliant per Microchip specification.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 25AA160T-I/P and 25LC160/P, the 25AA160/P uniquely supports 1.8 V operation while maintaining full PDIP-8 mechanical compatibility - making it the sole choice for legacy through-hole designs requiring lowest-voltage EEPROM interoperability.

Availability

25AA160/P is available at Aetrix Electronics and suitable for industrial sensor calibration storage, medical device configuration memory, and automotive body control module applications requiring stable component supply and long-term obsolescence management.

Supply support for 25AA160/P 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, manufacturing, and sales operations.

The 25AA160/P belongs to Microchip's legacy SPI Serial EEPROM product line, designed specifically for reliable, low-power nonvolatile data storage in industrial, automotive, and medical systems where pin compatibility and long-term data integrity are critical.

FAQ

What is the minimum supply voltage required for reliable operation of the 25AA160/P?

The 25AA160/P operates reliably down to 1.8 V, as specified in its DC characteristics table. At VCC = 1.8 V, the maximum clock frequency is reduced to 1 MHz, and input thresholds shift to VIH2 ≥ 0.7×VCC and VIL2 ≤ 0.3×VCC. This enables direct integration with 1.8 V microcontrollers without level translation, unlike higher-voltage variants such as the 25LC160/P.

How does the HOLD function behave during an active write cycle in the 25AA160/P?

The HOLD function cannot suspend an internal write cycle once initiated in the 25AA160/P. While HOLD pauses serial communication during read or instruction phases, it has no effect on ongoing self-timed erase/write operations. The device completes the write cycle regardless of HOLD state, and SO remains high-impedance until completion. This ensures data integrity but requires software to avoid asserting HOLD during WRITE sequences.

Can the 25AA160/P be used as a drop-in replacement for the 25C160/P in a 5 V system?

No - the 25AA160/P is not a drop-in replacement for the 25C160/P. Although both share the same PDIP-8 package and SPI interface, the 25C160/P is rated for 4.5–5.5 V operation and supports up to 3 MHz clocking, while the 25AA160/P is rated for 1.8–5.5 V but limited to 1 MHz at 5 V. Using 25AA160/P in place of 25C160/P may cause timing violations if the host SPI peripheral exceeds 1 MHz.

What happens to the write enable latch after issuing a WRITE instruction in the 25AA160/P?

After a successful WRITE instruction completes in the 25AA160/P, the write enable latch (WEL) is automatically reset to '0', disabling further writes until WREN is reissued. This occurs regardless of whether the write was to memory or the Status register, and applies even if CS remains low. The reset prevents accidental overwrites and enforces explicit re-enablement before subsequent writes - a key safety feature for robust firmware design.

Is the 25AA160/P still recommended for new designs according to Microchip documentation?

No - Microchip explicitly states "Not recommended for new designs" in the DS21231E datasheet for the 25AA160/P. The company recommends migrating to the enhanced 25AA160A/B or 25LC160A/B variants, which offer improved ESD performance, tighter AC timing, and extended qualification. However, the 25AA160/P remains fully supported for existing designs and legacy system maintenance.