Microchip Technology 25AA160B-I/SN

Overview

25AA160B-I/SN from Microchip Technology Inc. is a 16 Kbit (2048 × 8) SPI Serial EEPROM with 32-byte page size, 1.8–5.5 V supply range, and industrial temperature rating (–40°C to +85°C). It features hardware write protection via WP pin, HOLD functionality for interrupt-safe bus suspension, and self-timed 5 ms max write cycles. Used for nonvolatile parameter storage in microcontroller-based embedded systems requiring low-power, reliable data retention.

For engineers reviewing the 25AA160B-I/SN datasheet, 25AA160B-I/SN pinout, 25AA160B-I/SN application, or 25AA160B-I/SN equivalent, key selection criteria include SPI interface compatibility, 32-byte page write capability, 1.8 V minimum VCC support, industrial-temperature operation, and hardware write-protection configuration using WP and STATUS register bits BP0/BP1.

Technical Context

The 25AA160B-I/SN implements a standard SPI Mode 0,0/Motorola-compatible serial interface with separate SI (data in) and SO (data out) lines, CS-controlled device selection, and SCK-synchronized transfers. All instructions, addresses, and data are MSB-first, with read/write operations initiated only when CS is low and HOLD is high.

It integrates an 8-bit instruction register, internal address pointer that auto-increments during sequential reads, and a STATUS register with WIP (write-in-progress), WEL (write-enable latch), BP0/BP1 (block protection), and WPEN bits. Write enable must be explicitly set via WREN before any WRITE or WRSR command, and is automatically cleared after successful execution.

Key Specifications

Pinout & Package

25AA160B-I/SN is packaged in an 8-lead SOIC (Small Outline Integrated Circuit) with 150 mil body width, RoHS-compliant matte tin plating, and standard JEDEC MO-002AC footprint. Pin 1 is marked with a dot or notch; leads are gull-wing shaped with 1.27 mm pitch.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 25AA160A-I/SN and AT25160B-MAHL-T, the 25AA160B-I/SN uniquely combines 32-byte page writes, HOLD functionality, and consistent WPEN/BP bit behavior - making it optimal for interrupt-driven, high-reliability embedded systems where bus efficiency and deterministic suspend/resume are essential.

Availability

25AA160B-I/SN is available at Aetrix Electronics and suitable for industrial sensor calibration storage, medical device configuration memory, automotive body control module settings, smart energy meter firmware patch storage, and embedded system parameter retention requiring stable component supply across extended product lifecycles.

Supply support for 25AA160B-I/SN 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, FPGA, and memory solutions, headquartered in Chandler, Arizona, with global design, manufacturing, and sales operations.

The 25AA160B-I/SN belongs to Microchip's 25XX160 family of SPI Serial EEPROMs, designed specifically for robust, low-voltage, high-endurance nonvolatile data storage in space-constrained embedded systems requiring guaranteed 200-year data retention and 1 million write cycles.

FAQ

What is the maximum clock frequency supported by the 25AA160B-I/SN?

The 25AA160B-I/SN supports up to 10 MHz SPI clock frequency when VCC is 4.5 V to 5.5 V. At 2.5 V ≤ VCC < 4.5 V, maximum clock is 5 MHz; at 1.8 V ≤ VCC < 2.5 V, it is 3 MHz. These limits ensure reliable setup/hold timing across voltage and temperature ranges per DS21807D Table 1-2.

Does the 25AA160B-I/SN require external pull-up resistors on its SPI lines?

The 25AA160B-I/SN does not require external pull-ups on SI, SCK, or CS - these inputs have CMOS-compatible thresholds and function correctly with standard MCU GPIO outputs. However, SO and HOLD are open-drain-capable and may benefit from weak pull-ups (e.g., 10 kΩ) in noisy environments or multi-drop buses to ensure clean high-Z recovery.

How does the HOLD pin function during an active SPI transaction?

When HOLD is pulled low during an active SPI transaction (with CS low and SCK low), the 25AA160B-I/SN immediately suspends communication: SI, SO, and SCK enter high-impedance states, and the internal state machine pauses. Resuming requires bringing HOLD high while SCK remains low - then transmission continues from the exact bit position where it was interrupted.

Can the 25AA160B-I/SN be used with 3.3 V microcontrollers without level shifting?

Yes - the 25AA160B-I/SN operates natively from 1.8 V to 5.5 V and has VIH1 = 2.0 V (min) at VCC ≥ 2.7 V, ensuring reliable recognition of 3.3 V logic highs from standard 3.3 V MCUs. Its VOL = 0.4 V (max) at IOL = 2.1 mA also meets 3.3 V input low thresholds.

What happens to the write enable latch after a successful write operation on the 25AA160B-I/SN?

After a successful WRITE, WRSR, or WRDI instruction, the write enable latch (WEL bit in STATUS register) is automatically reset to '0'. This prevents unintended writes - each new write sequence must begin with an explicit WREN instruction followed by CS high-to-low transition to re-enable the latch.