Microchip Technology AT93C46C-10PI-2.7

Overview

AT93C46C-10PI-2.7 from Atmel (now Microchip) is a 1K-bit, 64-word × 16-bit serial EEPROM with 3-wire interface, low-voltage operation (2.7V–5.5V), Schmitt-trigger inputs, and 2 MHz clock rate at 5V. It delivers high reliability with 1 million write cycles and 100-year data retention, housed in an 8-lead PDIP package for industrial temperature range (−40°C to +85°C).

For engineers reviewing the AT93C46C-10PI-2.7 datasheet, AT93C46C-10PI-2.7 pinout, AT93C46C-10PI-2.7 application, or AT93C46C-10PI-2.7 equivalent, key selection considerations include its 3-wire serial protocol compatibility, VCC=2.7V minimum supply, self-timed 10 ms write cycle, READY/BUSY status reporting via DO, and dual-package availability (PDIP/SOIC) with industrial-grade qualification.

Technical Context

The AT93C46C-10PI-2.7 implements a synchronous 3-wire serial interface (CS, SK, DI/DO) with instruction-based memory access including READ, WRITE, ERASE, EWEN, EWDS, ERAL, and WRAL. Its logic-level input thresholds are VIL ≤ 0.3×VCC and VIH ≥ 0.7×VCC across 2.7V–5.5V operation, and it supports status polling via DO during write/erase cycles when CS is asserted after tCS ≥ 250 ns.

It features Schmitt-triggered, noise-filtered inputs, 5 pF max input/output capacitance, and operates with standby current as low as 14 µA at 2.7V. The device enters Erase/Write Disable (EWDS) state on power-up and requires explicit EWEN before programming - ensuring data integrity without external write-protection circuitry.

Key Specifications

Pinout & Package

AT93C46C-10PI-2.7 is supplied in an 8-lead PDIP (package code 8P3), 0.300" wide body, with standard through-hole mounting and JEDEC-compliant pin spacing.

Key Features

Applications

Equivalent & Alternatives

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

Compared with M95128-WMN6TP and 25AA010A-I/P, the AT93C46C-10PI-2.7 uniquely balances 16-bit word organization, true 2.7V operation, hardware READY/BUSY signaling, and industrial temperature rating - making it optimal for resource-constrained, safety-critical embedded systems requiring deterministic write timing and long-term data integrity.

Availability

AT93C46C-10PI-2.7 is available at Aetrix Electronics and suitable for industrial motor control, sensor calibration, smart metering, and automotive body electronics requiring stable component supply across extended temperature and long product lifecycles.

Supply support for AT93C46C-10PI-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

Atmel Corporation, now part of Microchip Technology, is a semiconductor company specializing in microcontrollers, nonvolatile memory, and secure authentication ICs for industrial, automotive, and IoT applications.

The AT93Cxx series was designed specifically for space-constrained, low-power embedded systems requiring robust serial EEPROM with deterministic timing, hardware write protection, and extended temperature operation - targeting programmable logic controllers, instrumentation, and automotive subsystems.

FAQ

What is the minimum supply voltage required for reliable operation of the AT93C46C-10PI-2.7?

The AT93C46C-10PI-2.7 is rated for guaranteed operation down to 2.7V across its full industrial temperature range (−40°C to +85°C). Below 2.7V, read functionality may degrade and write cycles are not characterized. This 2.7V minimum enables direct integration with 3.3V systems and brown-out tolerant designs without external regulators. Always maintain VCC ≥ 2.7V during active communication or write sequences to ensure AT93C46C-10PI-2.7 compliance with AC/DC specifications.

Does the AT93C46C-10PI-2.7 support hardware write protection independent of software commands?

No, the AT93C46C-10PI-2.7 does not include dedicated hardware write-protect pins (e.g., WP or ORG). Write protection is implemented exclusively through the Erase/Write Disable (EWDS) instruction, which must be issued after programming to lock the memory array. The device powers up in EWDS state, so AT93C46C-10PI-2.7 remains write-protected until explicitly enabled via EWEN - providing software-controlled, instruction-level security without external components.

Can the AT93C46C-10PI-2.7 be used with a 3.3V microcontroller without level shifters?

Yes, the AT93C46C-10PI-2.7 supports 3.3V operation with VCC = 3.3V, and its input thresholds (VIL ≤ 0.3×VCC ≈ 0.99V, VIH ≥ 0.7×VCC ≈ 2.31V) are fully compatible with standard 3.3V CMOS logic levels. Its 5 pF input capacitance and Schmitt-trigger inputs further ensure noise-immune interfacing. As long as the host MCU drives CS, SK, and DI within these voltage ranges, AT93C46C-10PI-2.7 operates reliably without level-shifting circuitry.

What is the purpose of the NC and DC pins on the AT93C46C-10PI-2.7 PDIP package?

The NC (No Connect) and DC (Don't Connect) pins on the AT93C46C-10PI-2.7 are internally unconnected and must remain floating - neither tied to VCC, GND, nor pulled. NC is a standard designation for unused bond pads; DC indicates a reserved pin with no internal connection. Leaving them unconnected ensures correct electrical behavior and avoids unintended leakage paths. This requirement applies strictly to AT93C46C-10PI-2.7 and is documented in the official Atmel datasheet Rev. 1122D.

How does the AT93C46C-10PI-2.7 indicate completion of a write cycle?

The AT93C46C-10PI-2.7 uses its DO pin to report READY/BUSY status: after initiating a WRITE or ERASE command, if CS is brought low again for ≥250 ns (tCS) and then raised while SK remains idle, DO outputs '0' (BUSY) during programming or '1' (READY) upon completion. This hardware status signal eliminates fixed timeouts and enables precise synchronization - a core feature distinguishing AT93C46C-10PI-2.7 from simpler EEPROMs lacking real-time feedback.