Microchip Technology 25AA160B-I/MS

Overview

25AA160B-I/MS 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), housed in an 8-lead MSOP package. It features hardware write protection via WP pin, HOLD functionality for interrupt-safe bus suspension, and self-timed 5 ms max write cycles - deployed in embedded systems for configuration storage, calibration data retention, and firmware parameter backup.

For engineers reviewing the 25AA160B-I/MS datasheet, 25AA160B-I/MS pinout, 25AA160B-I/MS application, or 25AA160B-I/MS equivalent, key selection criteria include SPI clock compatibility up to 10 MHz at 1.8 V, page-size-aware firmware handling (32-byte boundary), VCC-dependent timing margins, and hardware/software write-protection interaction (WPEN bit + WP pin).

Technical Context

The 25AA160B-I/MS implements a standard SPI Mode 0,0/Master-Slave interface with separate SI (data-in) and SO (data-out) lines, requiring CS assertion, SCK synchronization, and optional HOLD/HP for transaction pausing. Its internal architecture includes a status register with WIP, WEL, BP0/BP1, and WPEN bits, enabling nonvolatile block protection (none/1/4/1/2/all array) and hardware write-lock control.

Write operations require explicit WREN instruction before WRITE, followed by CS high to trigger internal 5 ms erase/write cycle; reads support sequential addressing with automatic address rollover at 07FFh. The device resets to standby mode on power-up with WEL cleared, SO in high-Z, and no active writes pending.

Key Specifications

Pinout & Package

8-lead MSOP (150 mil) package with exposed pad option not specified; footprint compatible with JEDEC MO-187AA, 3.0 mm × 4.9 mm body, 0.65 mm lead pitch.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 25AA160B-I/MS, the 25AA160A-I/MS reduces page granularity (impacting firmware efficiency), while the AT25160B-MAHL-T sacrifices 1.8 V operation and HOLD support - making 25AA160B-I/MS the optimal choice for flexible, low-voltage, interrupt-resilient embedded storage.

Availability

25AA160B-I/MS is available at Aetrix Electronics and suitable for industrial sensor nodes, medical device calibration storage, automotive body control modules, smart energy meters, and IoT endpoint configuration management requiring stable component supply across extended product lifecycles.

Supply support for 25AA160B-I/MS 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 U.S.-based semiconductor manufacturer specializing in microcontrollers, analog devices, and memory solutions, with a focus on embedded control and connectivity.

The 25AA160B-I/MS belongs to Microchip's 25XX160 family of SPI EEPROMs, designed specifically for reliable, low-power, nonvolatile data storage in space-constrained industrial, medical, and automotive applications where write endurance and voltage flexibility are critical.

FAQ

What is the maximum SPI clock frequency supported by the 25AA160B-I/MS at 1.8 V?

The 25AA160B-I/MS supports up to 3 MHz SPI clock frequency when VCC is between 1.8 V and 2.5 V, as specified in Table 1-2 AC Characteristics. This limit ensures reliable setup/hold timing (Tsu = 30 ns, THD = 50 ns) and prevents metastability in the internal shift register. Operating above this frequency risks read/write corruption and is not guaranteed by Microchip's characterization.

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

When the HOLD pin is pulled low during an active SPI transaction on the 25AA160B-I/MS, the device immediately suspends communication: SI, SO, and SCK inputs are ignored (except CS), SO enters high-impedance, and the internal address pointer and instruction state are preserved. Resuming requires bringing HOLD high while SCK is low - then transmission continues from the exact bit position where it paused, with no reinitialization needed.

Can the 25AA160B-I/MS be used with a 5 V microcontroller without level shifting?

Yes, the 25AA160B-I/MS supports VCC from 1.8 V to 5.5 V and has CMOS-compatible inputs (VIH1 = 2.0 V min at VCC ≥ 2.7 V; VIH2 = 0.7×VCC min at VCC < 2.7 V). When powered at 5 V, its SI pin accepts 3.5 V–5.5 V as valid high - fully compatible with 5 V MCU outputs. No level shifter is required if both VCC and MCU I/O share the same 5 V rail.

What happens if a page write crosses a 32-byte boundary on the 25AA160B-I/MS?

If a page write command on the 25AA160B-I/MS attempts to cross a 32-byte boundary (e.g., writing 32 bytes starting at address 001Fh), the data wraps around to the start of the same page (0000h) instead of advancing to the next page. This overwrites previously written bytes in that page. Firmware must validate address alignment and split writes across boundaries - the device provides no error detection or auto-correction for this condition.

Is the 25AA160B-I/MS RoHS compliant and Pb-free?

Yes, the 25AA160B-I/MS is Pb-free and RoHS compliant, as explicitly stated in the "Features" section of DS21807D and confirmed in the Packaging Information (Section 4.1). The MSOP package carries the JEDEC Pb-free designator (3e), and all marking codes (e.g., "5AAB") correspond to RoHS-compliant variants per Microchip's documentation.