Microchip Technology 25AA160D-I/ST

Overview

25AA160D-I/ST from Microchip Technology 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 grade (−40°C to +85°C). It features hardware write protection via WP pin, HOLD functionality for interrupt-safe bus suspension, and supports up to 10 MHz clock at 4.5–5.5 V. It is used in embedded systems for storing configuration data, calibration parameters, and firmware boot flags.

For engineers reviewing the 25AA160D-I/ST datasheet, 25AA160D-I/ST pinout, 25AA160D-I/ST application, or 25AA160D-I/ST equivalent, key selection criteria include page size (32 bytes), voltage compatibility (1.8 V min), HOLD/CS timing margins, and block protection granularity (1/4, 1/2, or full array).

Technical Context

The 25AA160D-I/ST implements a standard SPI Mode 0,0 interface (CPOL = 0, CPHA = 0) with separate SI and SO lines, requiring CS assertion before any instruction. Its internal architecture includes an 8-bit instruction register, page latches, and HV generator for EEPROM programming - all managed by on-chip control logic without external components.

Write operations require explicit WREN instruction followed by WRITE command and address; the device automatically increments the internal address pointer during sequential reads. Block protection is controlled nonvolatively via BP0/BP1 bits in the STATUS register, enabling selective locking of upper 1/4 (0600h–07FFh), upper 1/2 (0400h–07FFh), or entire memory array (0000h–07FFh).

Key Specifications

Pinout & Package

25AA160D-I/ST is packaged in an 8-lead TSSOP (ST) with 3.0 mm × 4.4 mm body, 0.65 mm lead pitch, and Pb-free/RoHS-compliant finish. Pin 1 is CS (Chip Select), pin 2 is SO (Serial Output), pin 3 is WP (Write-Protect), pin 4 is VSS (Ground), pin 5 is SI (Serial Input), pin 6 is SCK (Serial Clock), pin 7 is HOLD (Hold Input), and pin 8 is VCC (Supply Voltage).

Key Features

Applications

Equivalent & Alternatives

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

Compared with 25LC160D-I/ST, the 25AA160D-I/ST adds 1.8 V support and identical pinout - making it drop-in for low-voltage upgrades. Versus AT25DF021-SSH-T, it offers true byte-write capability, integrated HOLD/WP, and simpler driver implementation for small-parameter storage.

Availability

25AA160D-I/ST is available at Aetrix Electronics and suitable for industrial control configuration storage, medical device calibration data retention, and automotive body control module settings requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for 25AA160D-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, serving industrial, automotive, and consumer markets with high-reliability silicon and development tools.

The 25AA160D-I/ST belongs to Microchip's 25XX160 family of SPI Serial EEPROMs, designed specifically for robust, low-power, and pin-compatible nonvolatile storage in resource-constrained embedded systems.

FAQ

What is the maximum clock frequency supported by the 25AA160D-I/ST, and how does it vary with supply voltage?

The 25AA160D-I/ST supports up to 10 MHz clock frequency when VCC 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 of the DS22150B datasheet and reflect guaranteed AC timing margins across the full industrial temperature range. The 25AA160D-I/ST must operate within these bounds to ensure reliable instruction decoding and data transfer integrity.

Does the 25AA160D-I/ST support page write operations, and what is the page size?

Yes, the 25AA160D-I/ST supports page write operations with a fixed 32-byte page size, as confirmed in the Device Selection Table and Section 2.3 of the datasheet. Page writes allow up to 32 consecutive bytes to be loaded before triggering the internal 5 ms write cycle - provided all addresses reside within the same physical page boundary (e.g., 0000h–001Fh, 0020h–003Fh, etc.). Attempting to cross a page boundary causes wraparound within the current page.

How does the HOLD pin function on the 25AA160D-I/ST, and what are the timing requirements?

The HOLD pin on the 25AA160D-I/ST suspends ongoing SPI communication without resetting the internal state. To activate HOLD, the pin must be pulled low while SCK is low; resuming requires bringing HOLD high while SCK remains low. Timing parameters THS (HOLD setup) and THH (HOLD hold) are specified in Table 1-2 and depend on VCC - e.g., THS = 20 ns minimum at 4.5–5.5 V. The 25AA160D-I/ST maintains its position in the instruction/address/data sequence and resumes precisely where paused.

What write protection mechanisms are implemented in the 25AA160D-I/ST?

The 25AA160D-I/ST implements three layered write protections: (1) a volatile write enable latch (WEL bit) set via WREN instruction, (2) nonvolatile block protection (BP0/BP1 bits) controlling 1/4, 1/2, or full array lock, and (3) hardware write protection using the WP pin in conjunction with the WPEN bit in the STATUS register. All mechanisms are documented in Sections 2.4–2.6 and Table 2-4 of the DS22150B datasheet. The 25AA160D-I/ST requires explicit WREN before any write, even when block protection is disabled.

Is the 25AA160D-I/ST pin-compatible with other members of the 25XX160 family, such as the 25LC160D-I/ST?

Yes, the 25AA160D-I/ST is pin-compatible and functionally identical to the 25LC160D-I/ST in the same package (e.g., TSSOP-8), sharing identical pinout, instruction set, timing, and protection features. The only functional difference is the supply voltage range: 25AA160D-I/ST operates from 1.8 V to 5.5 V, whereas 25LC160D-I/ST requires minimum 2.5 V. This makes the 25AA160D-I/ST a direct upgrade for 1.8 V systems without PCB changes.