Microchip Technology 93LC46/P

Overview

93LC46/P from Microchip Technology Inc. is a 1K-bit low-voltage serial EEPROM with Microwire-compatible 3-wire interface, configurable as 128 × 8 or 64 × 16 organization via ORG pin, rated for -40°C to +85°C operation in 8-pin PDIP package, and optimized for nonvolatile storage in embedded control and power management systems.

For engineers reviewing the 93LC46/P datasheet, 93LC46/P pinout, 93LC46/P application, or 93LC46/P equivalent, key selection criteria include its 2.5V–5.5V single-supply operation, 1,000,000 erase/write endurance, 200-year data retention, and self-timed erase/write cycles with device status signaling via DO pin.

Technical Context

The 93LC46/P implements a synchronous serial Microwire interface with CS, CLK, DI, and DO signals, where instruction execution begins on detection of a Start condition (CS high and DI high on first CLK rising edge). Memory organization is dynamically selected by ORG pin logic level - VCC enables x16 mode (64 words), VSS enables x8 mode (128 bytes).

Internal architecture includes an address decoder, data register, and memory array with automatic ERAL-before-WRAL sequencing, power-on/off data protection circuitry, and Ready/Busy status reporting via DO pin during erase/write operations. All programming requires prior EWEN command and is inhibited below 1.4V VCC.

Key Specifications

Pinout & Package

8-pin PDIP (300 mil) package per JEDEC MS-001 standard, with through-hole mounting and 2.54 mm pitch. Pin 1 marked by notch or dot; pin numbering follows standard DIP convention (counterclockwise from notch).

Key Features

Applications

Equivalent & Alternatives

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

Compared with 93LC46C/P and AT93C46-PU, the 93LC46/P offers identical core functionality but lacks the enhanced ESD robustness of the 'C' revision and has no second-source validation history - best suited for legacy maintenance rather than new development.

Availability

93LC46/P is available at Aetrix Electronics and suitable for industrial sensor calibration storage, consumer appliance configuration memory, and embedded power management unit applications requiring stable component supply across extended product lifecycles.

Supply support for 93LC46/P 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 memory solutions, headquartered in Chandler, Arizona, with global design, manufacturing, and sales operations.

The 93LC46/P belongs to Microchip's legacy 93LC serial EEPROM product line, designed specifically for cost-sensitive, low-power embedded systems requiring simple, reliable nonvolatile storage with minimal pin count and board space.

FAQ

What is the memory organization flexibility of the 93LC46/P?

The 93LC46/P supports dual memory configurations: 128 × 8-bit (x8) when ORG is tied to VSS, or 64 × 16-bit (x16) when ORG is tied to VCC. This allows system designers to match the device to their MCU's data bus width without changing firmware logic - the 93LC46/P automatically interprets address and data width based on ORG state, and both modes are fully supported across the full -40°C to +85°C temperature range.

How does the 93LC46/P handle power transitions to prevent data corruption?

The 93LC46/P incorporates hardware-level power-on/off data protection that inhibits all erase/write operations when VCC falls below or rises above 1.4V. This ensures that partial writes cannot occur during brown-out or startup sequences. Additionally, the device powers up in Erase/Write Disable (EWDS) mode, requiring an explicit EWEN command before any programming - this dual-layer protection makes the 93LC46/P highly resilient in unstable power environments.

Can the 93LC46/P be used with modern 3.3V microcontrollers without level shifters?

Yes, the 93LC46/P operates natively from 2.5V to 5.5V, with guaranteed logic thresholds (VIH ≥ 0.7×VCC, VIL ≤ 0.2×VCC) and output drive strength compliant at 3.3V. Its 100 µA typical active read current at 2.5V and 3 µA standby current make it ideal for direct interfacing with 3.3V MCUs - no level-shifting circuitry is needed, reducing BOM cost and PCB area while maintaining full timing compliance per DS21712C.

What is the role of the DO pin during programming operations?

During erase or write cycles, the DO pin serves as a Ready/Busy status indicator: logic low means the operation is still in progress, and logic high indicates completion. This allows firmware to poll the 93LC46/P without blocking CPU execution - after initiating a WRITE or ERASE command, the host MCU can repeatedly sample DO (with CS high and ≥250 ns CS low time observed) until it reads high, then proceed safely. The 93LC46/P guarantees TSV ≤ 500 ns for status validity.

Is the 93LC46/P suitable for new designs, or is it obsolete?

The 93LC46/P is marked "Not recommended for new designs" in Microchip's official documentation, with the 93LC46C/P designated as the preferred replacement. However, the 93LC46/P remains fully functional, in active distribution, and supported for legacy repair, continuity programs, and cost-sensitive applications where the enhanced ESD rating of the 'C' revision is not required - Aetrix Electronics maintains stable inventory and lifecycle coordination for ongoing 93LC46/P demand.