Microchip Technology AT25040A-10TI-2.7

Overview

AT25040A-10TI-2.7 from Atmel (now Microchip) is a 4-kbit SPI serial EEPROM organized as 512 words × 8 bits, operating from 2.7V to 5.5V with 20 MHz max clock rate at 5V, 8-byte page write capability, and hardware/software write protection. It serves as nonvolatile configuration storage in microcontroller-based industrial control modules requiring reliable low-voltage data retention.

For engineers reviewing the AT25040A-10TI-2.7 datasheet, AT25040A-10TI-2.7 pinout, AT25040A-10TI-2.7 application, or AT25040A-10TI-2.7 equivalent, key selection criteria include VCC range compatibility (2.7–5.5V), TSSOP-8 package footprint, 1M write endurance, 100-year data retention, and SPI Mode 0/3 interface timing compliance.

Technical Context

The AT25040A-10TI-2.7 implements a synchronous SPI slave interface with dedicated SI/SO pins, CS-controlled selection, and HOLD/ WP pins for communication suspension and hardware write inhibition. Its internal architecture includes an 8-bit instruction register, status register with BP1/BP0 block protection bits, and automatic address increment during sequential reads.

It supports four block write protection levels (none, 1/4, 1/2, or full array) via nonvolatile status register bits, self-timed 5 ms max write cycles without erase pre-conditioning, and operates across −40°C to +85°C industrial temperature range in lead-free TSSOP-8 packaging.

Key Specifications

Pinout & Package

AT25040A-10TI-2.7 is supplied in an 8-lead Thin Shrink Small Outline Package (TSSOP), 0.170" wide, with 0.65 mm pitch, JEDEC MO-153 compliant, footprint compatible with SOIC-8 but with reduced height and smaller body (3.00 mm × 4.40 mm).

Key Features

Applications

Equivalent & Alternatives

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

Compared with M95040-DRMN3TP/K and BR24G04FJ-WE2, the AT25040A-10TI-2.7 uniquely combines SPI Mode 0/3 support, HOLD pin for interrupt-safe transfers, and dual hardware/software write protection - making it optimal for real-time embedded systems where bus arbitration and data integrity are critical.

Availability

AT25040A-10TI-2.7 is available at Aetrix Electronics and suitable for industrial control systems, automotive body electronics, medical diagnostics equipment, and smart metering applications requiring stable component supply and long-term lifecycle support.

Supply support for AT25040A-10TI-2.7 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 (formerly Atmel) is a global semiconductor company specializing in microcontrollers, analog devices, and nonvolatile memory solutions for industrial, automotive, and consumer markets.

The AT25040A-10TI-2.7 belongs to Microchip's legacy AT25 SPI EEPROM product line, designed specifically for space-constrained, low-power embedded systems needing robust, pin-efficient serial configuration storage.

FAQ

What is the maximum clock frequency supported by AT25040A-10TI-2.7?

The AT25040A-10TI-2.7 supports up to 20 MHz SCK frequency at VCC = 5.0V, 10 MHz at 2.7V, and 5 MHz at 1.8V. These values are specified in Table 4 of the datasheet and reflect guaranteed AC timing performance across voltage ranges. Operation above these frequencies may result in unreliable communication or data corruption. The AT25040A-10TI-2.7 does not include internal clock multiplication or PLL circuitry - all timing is strictly synchronous to the externally applied SCK signal.

Does AT25040A-10TI-2.7 require an external pull-up resistor on the SO pin?

No, the AT25040A-10TI-2.7 features an actively driven SO output that transitions between defined VOH/VOL levels and enters high-impedance state when CS is high or HOLD is asserted. External pull-ups are unnecessary and may cause contention or increased power consumption. The AT25040A-10TI-2.7 datasheet specifies SO drive strength (IOH = −1.6 mA at 5V) and explicitly defines high-Z behavior - confirming no external termination is required for proper SPI bus operation.

How does the HOLD function behave during an active write cycle in AT25040A-10TI-2.7?

The HOLD pin has no effect during an internal write cycle (tWC); once initiated, the AT25040A-10TI-2.7 ignores HOLD assertions until the write completes. During active write, only RDSR is accepted to monitor RDY status. HOLD is functional only during read, write setup, or status register access phases - allowing safe suspension before write initiation or after completion. This behavior ensures data integrity: the AT25040A-10TI-2.7 will never abort or corrupt an in-progress write due to HOLD activation.

Can AT25040A-10TI-2.7 be used with 1.8V microcontrollers?

No - the AT25040A-10TI-2.7 is a 2.7V variant (suffix -2.7), rated for 2.7V to 5.5V operation only. For 1.8V systems, the correct part is AT25040A-10TI-1.8, which guarantees functionality down to 1.8V and uses different DC/AC characterization. Using AT25040A-10TI-2.7 below 2.7V risks undervoltage lockout, incorrect status register reads, or failed write cycles. Always match the suffix (-2.7 or -1.8) to the host system's VCC rail.

What happens if the WP pin is pulled low during a write command sequence to AT25040A-10TI-2.7?

If WP is pulled low after CS goes low but before the internal write cycle begins, the AT25040A-10TI-2.7 aborts the write operation and returns to standby - no data is written and the status register remains unchanged. If WP is pulled low after the internal write has started (i.e., after CS rising edge), the AT25040A-10TI-2.7 ignores the WP transition and completes the write normally. This behavior is documented in the "WRITE PROTECT" section and ensures predictable failure modes: AT25040A-10TI-2.7 either blocks writes entirely or executes them fully, with no partial or corrupted writes.