Microchip Technology AT25640B-SSPDGV-T

Overview

AT25640B-SSPDGV-T from Microchip Technology is a 64 Kbit (8,192 × 8) SPI serial EEPROM optimized for automotive applications, supporting AEC-Q100 Grade 1 (−40°C to +125°C), 1.7V–5.5V operation, 5 MHz clock rate at 5V, and 32-byte page write mode. It integrates hardware/software write protection via WP pin and STATUS register, and features 1,000,000 write cycles with 100-year data retention.

For engineers reviewing the AT25640B-SSPDGV-T datasheet, AT25640B-SSPDGV-T pinout, AT25640B-SSPDGV-T application, or AT25640B-SSPDGV-T equivalent, this page delivers verified electrical specs, SPI interface timing constraints, automotive-grade reliability metrics, and validated alternative parts for functional substitution in engine control units, ADAS modules, and body electronics designs.

Technical Context

The AT25640B-SSPDGV-T implements a synchronous SPI slave interface compliant with Modes 0 and 3, latching input on SCK rising edge and outputting on falling edge. Its internal architecture includes a high-voltage generation circuit for EEPROM programming, a STATUS register with nonvolatile BP1/BP0 block protection bits, and a power-on reset (POR) circuit ensuring stable initialization at ≥100 µs after VCC stabilization.

It supports dual-voltage operation: Grade 1 (2.5V–5.5V, −40°C to +125°C) and Grade 3 (1.7V–5.5V, −40°C to +85°C). The HOLD pin enables pause/resume of ongoing SPI transfers without resetting the sequence, while the WP pin-when enabled via WPEN bit-blocks STATUS register writes when pulled low.

Key Specifications

Pinout & Package

AT25640B-SSPDGV-T uses an 8-lead SOIC package with standard pinout and 1.27 mm pitch. All pins are electrically validated per DS20006310A, with no variant-specific deviations.

Key Features

Applications

Equivalent & Alternatives

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

Compared with M95640-DRMN6TP/K and BR24G64FJ-3GE2, the AT25640B-SSPDGV-T uniquely combines SPI Mode 0/3 flexibility, HOLD pin support, and full AEC-Q100 Grade 1 qualification-making it the only option among the three qualified for engine bay deployment with deterministic interrupt handling.

Availability

AT25640B-SSPDGV-T is available at Aetrix Electronics and suitable for automotive engine control units, ADAS sensor modules, and body electronics requiring stable component supply across extended temperature and voltage ranges.

Supply support for AT25640B-SSPDGV-T 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 is a global semiconductor company specializing in microcontrollers, analog devices, and memory solutions, with deep expertise in automotive-grade IC design and qualification.

The AT25640B-SSPDGV-T belongs to Microchip's AT25xxxB automotive EEPROM family, engineered specifically for AEC-Q100-compliant data storage in harsh-temperature environments where reliability, low-voltage operation, and SPI interoperability are essential.

FAQ

What is the maximum clock frequency supported by the AT25640B-SSPDGV-T?

The AT25640B-SSPDGV-T supports a maximum SCK clock frequency of 5 MHz when operated at VCC = 5.0V. At lower supply voltages (e.g., 1.7V–2.5V), the maximum rated frequency remains 5 MHz per DS20006310A AC characteristics table, though system-level timing margins may require derating in marginal layouts. This rating applies across the full −40°C to +125°C Grade 1 temperature range.

Does the AT25640B-SSPDGV-T support both SPI Mode 0 and Mode 3?

Yes, the AT25640B-SSPDGV-T explicitly supports SPI Modes 0 (CPOL = 0, CPHA = 0) and 3 (CPOL = 1, CPHA = 1), as confirmed in the Features section of DS20006310A. Data is always latched on the rising edge of SCK and output on the falling edge; the only difference is SCK idle polarity. Mode selection is determined by the host controller-no device configuration is required.

How does the HOLD pin function during an active write cycle in the AT25640B-SSPDGV-T?

The HOLD pin has no effect on an ongoing internal write cycle in the AT25640B-SSPDGV-T. As stated in Section 5.3, "the Hold mode does not have an effect on the internal write cycle." While HOLD can pause SPI command reception and data transfer, the self-timed 5 ms write operation continues uninterrupted once initiated. This ensures data integrity during system interrupts without compromising write completion guarantees.

What is the factory default state of the STATUS register in the AT25640B-SSPDGV-T?

Per Section 4.6.6 of DS20006310A, the AT25640B-SSPDGV-T ships with the STATUS register configured as follows: WPEN = 0 (write protection disabled), BP1 = 0 and BP0 = 0 (no block protection), WEL = 0 (write latch reset), and RDY/BSY = 0 (ready state). The EEPROM array itself is pre-programmed to 0xFFh (all bits logic '1'), enabling immediate use without initialization overhead.

Is the AT25640B-SSPDGV-T pin-compatible with other members of the AT25xxxB family?

Yes, the AT25640B-SSPDGV-T shares identical pinout, package dimensions, and electrical interface behavior with AT25080B, AT25160B, and AT25320B in the same SOIC package variant (e.g., AT25080B-SSHD-T). Memory size differences do not affect pin assignment, timing, or command set-enabling drop-in replacement in designs where capacity scaling is acceptable and firmware handles address space boundaries.