Microchip Technology AT45DB161B-TC

Overview

AT45DB161B-TC from Microchip Technology (formerly Atmel) is a 16-Mbit serial DataFlash memory IC with SPI interface, organized as 4096 pages × 528 bytes, featuring dual 528-byte SRAM buffers and hardware write protection. It operates from a single 2.5V–3.6V or 2.7V–3.6V supply, supports up to 20 MHz clock frequency, and delivers 4 mA typical active read current - ideal for embedded code shadowing and firmware storage in space-constrained industrial controllers.

For engineers reviewing the AT45DB161B-TC datasheet, AT45DB161B-TC pinout, AT45DB161B-TC application, or AT45DB161B-TC equivalent, this page provides verified pin functions, real-world timing behavior (e.g., tEP ≤ 20 ms page program with built-in erase), buffer co-processing capability, continuous array read wraparound behavior, and validated alternatives for legacy migration or supply continuity.

Technical Context

The AT45DB161B-TC implements a three-tier memory architecture (pages, blocks, sectors) with dedicated SRAM buffers enabling simultaneous data reception and nonvolatile reprogramming. Its SPI interface supports Mode 0 and Mode 3, with all commands initiated via CS low followed by 8-bit opcodes and address sequences aligned to PA11–PA0 (page) and BA9–BA0 (byte) addressing.

Internally self-timed operations include page/block erase, buffer-to-main-memory programming (with or without built-in erase), and main memory page-to-buffer transfer. The RDY/BUSY pin reflects Flash array activity only; buffer reads/writes remain accessible during array busy states, enabling pipelined data streaming.

Key Specifications

Pinout & Package

AT45DB161B-TC is supplied in a 28-pin TSOP-I (Thin Small Outline Package) with 0.55 mm pitch, compliant with JEDEC MO-153. Pin numbering follows standard TSOP top-view orientation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AT45DB161D-TC, the AT45DB161B-TC offers lower cost and proven field reliability but lacks extended temperature support and faster program timing; versus W25Q16JVSSIQ, it provides deterministic buffer pipelining and simpler SPI driver implementation at the expense of peak bandwidth.

Availability

AT45DB161B-TC is available at Aetrix Electronics and suitable for industrial control panels, medical diagnostic equipment, and smart metering systems requiring stable component supply, long-term obsolescence management, and guaranteed traceable sourcing.

Supply support for AT45DB161B-TC 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 acquired Atmel in 2016 and maintains full product support, documentation, and manufacturing continuity for the DataFlash family.

The AT45DB161B-TC belongs to Microchip's legacy DataFlash series, designed specifically for embedded systems requiring SPI-based nonvolatile storage with integrated buffering and hardware write protection - prioritizing ease of integration over raw speed.

FAQ

What is the maximum clock frequency supported by the AT45DB161B-TC?

The AT45DB161B-TC supports a maximum serial clock (SCK) frequency of 20 MHz across all operating voltages and temperatures. This timing is validated for both read and write operations including Continuous Array Read, Main Memory Page Read, and Buffer Write commands. Exceeding 20 MHz may result in command rejection or data corruption, as confirmed by the AC characteristics table in the official Microchip datasheet (Rev. 2224G).

Does the AT45DB161B-TC require a high-voltage programming signal?

No, the AT45DB161B-TC does not require high-voltage programming signals. All program and erase operations execute from the same 2.5V–3.6V or 2.7V–3.6V supply used for read operations. The device uses internally generated high-voltage charge pumps, eliminating external VPP pins or voltage translators - a key design advantage confirmed in the "To allow for simple in-system reprogrammability" section of the datasheet.

How does the RDY/BUSY pin behave during buffer-only operations?

The RDY/BUSY pin remains high during Buffer Read, Buffer Write, and Status Register Read operations because these commands do not access the Flash memory array. It only goes low during Group A operations involving the array (e.g., Page Erase, Buffer-to-Main-Memory Program). This behavior enables concurrent buffer access while Flash is busy - a feature explicitly documented in the "Operation Mode Summary" section of the AT45DB161B-TC datasheet.

Can the AT45DB161B-TC be used for EEPROM emulation?

Yes, the AT45DB161B-TC supports EEPROM emulation via a self-contained three-step Read-Modify-Write operation using its dual buffers. The process involves transferring a page to a buffer, modifying bytes in the buffer, then programming the updated data back to Flash - all without external address latches or complex timing. This capability is explicitly stated in the device description and validated by the Auto Page Rewrite (0x58/0x59) command functionality.

What is the purpose of the 5.0V-tolerant inputs on the AT45DB161B-TC?

The SI, SCK, CS, RESET, and WP pins on the AT45DB161B-TC are 5.0V-tolerant to simplify interface design with legacy 5V microcontrollers, FPGAs, or level-shifting circuits. This tolerance allows direct connection without external voltage translators, reducing BOM count and layout complexity - a feature explicitly called out in the "Features" list and verified in the Absolute Maximum Ratings table of the datasheet.