Microchip Technology 93LC46A-E/P

Overview

93LC46A-E/P from Microchip Technology Inc. is a 1Kbit (128 × 8-bit) low-voltage serial EEPROM with Microwire-compatible 3-wire interface, 2.5–5.5V supply range, and industrial/automotive temperature support (−40°C to +125°C). It features self-timed erase/write cycles, automatic ERAL before WRAL, power-on/off data protection, and Ready/Busy status signaling via DO pin - used in embedded system configuration storage and calibration data retention.

For engineers reviewing the 93LC46A-E/P datasheet, 93LC46A-E/P pinout, 93LC46A-E/P application, or 93LC46A-E/P equivalent, key selection criteria include VCC operating range (2.5–5.5V), 8-bit fixed organization (no ORG pin), automotive-grade temperature rating, and PDIP-8 package compatibility with legacy through-hole designs.

Technical Context

The 93LC46A-E/P implements a synchronous serial Microwire interface with CS, CLK, and DI/DO pins - no ORG pin present, enforcing fixed 128 × 8-bit memory mapping. Communication uses start-bit detection followed by opcode, address, and data clocked on CLK rising edges.

It supports five core instructions: READ (18 clocks), WRITE (18 clocks), ERASE (10 clocks), ERAL (10 clocks), and WRAL (18 clocks), all with self-timed internal programming cycles (TWC = 6 ms for erase/write, TEC = 6 ms for ERAL, TWL = 15 ms for WRAL at VCC ≥ 4.5V). Power-on reset logic disables writes until explicit EWEN command is issued.

Key Specifications

Pinout & Package

93LC46A-E/P is supplied in an 8-lead PDIP (Plastic Dual In-line Package) with 0.3-inch body width and standard through-hole mounting. Pin 1 is marked by laser dot or notch; package meets RoHS and Pb-free (Matte Tin) requirements.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 93LC46B-E/P, the 93LC46A-E/P provides simpler 8-bit byte-aligned access and eliminates ORG pin management; versus AT25010B-MAHL-T, it offers automotive temperature rating and hardware-accelerated array-wide operations critical for robust ECU firmware updates.

Availability

93LC46A-E/P is available at Aetrix Electronics and suitable for industrial sensor calibration, automotive ECU configuration, and medical device settings requiring stable component supply across extended product lifecycles.

Supply support for 93LC46A-E/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 microcontrollers, analog devices, and memory solutions, headquartered in Chandler, Arizona.

The 93LC46A-E/P belongs to Microchip's legacy 93XX serial EEPROM product line, designed specifically for cost-sensitive, low-power, nonvolatile data storage in space-constrained embedded systems with strict automotive and industrial reliability requirements.

FAQ

What is the memory organization of the 93LC46A-E/P?

The 93LC46A-E/P has a fixed 128 × 8-bit organization (1 Kbit total), with no ORG pin - unlike 'C' variants, it does not support configurable word size. This simplifies PCB layout and firmware development by eliminating external logic for ORG pin control. All address and data transfers operate in strict 8-bit mode, matching legacy 93C46A designs while adding wider VCC and automotive temperature support.

Does the 93LC46A-E/P require an external pull-up resistor on the DO pin?

No, the 93LC46A-E/P does not require an external pull-up on DO. The DO pin actively drives high/low during READ and Ready/Busy status reporting, and enters High-Z state when deselected or between operations. However, if DI and DO are wire-OR'd (shared bus), a current-limiting resistor is recommended to prevent bus conflict during the dummy zero preceding READ - per Microchip DS20001749K Section 2.2.

What is the minimum VCC required for reliable operation of the 93LC46A-E/P?

The 93LC46A-E/P requires VCC ≥ 2.5 V for guaranteed operation across its full temperature range (−40°C to +125°C). Its internal voltage detect circuit (VPOR) holds the device in write-inhibit state below ~1.5 V, preventing corruption during power ramp-up or brown-out. Operation below 2.5 V is not characterized and may result in undefined behavior or failed writes.

Can the 93LC46A-E/P be used as a drop-in replacement for the 93C46A-P?

The 93LC46A-E/P shares identical PDIP-8 pinout and 8-bit organization with the 93C46A-P, but differs in VCC range (2.5–5.5 V vs. 4.5–5.5 V) and temperature grade (−40°C to +125°C vs. −40°C to +85°C). It is not a direct drop-in replacement in 4.5 V-only systems due to lower VCC min, but is fully compatible in 5 V designs with extended thermal requirements - verify power supply stability and timing margins per DS20001749K AC characteristics.

How does the ERAL command function in the 93LC46A-E/P?

The ERAL (Erase All) command in the 93LC46A-E/P erases the entire 128-byte memory array to logical '1' in a single self-timed cycle (TEC = 6 ms at VCC ≥ 4.5 V). It executes only when the device is in EWEN (Erase/Write Enable) state and requires VCC ≥ 4.5 V for proper operation. Unlike discrete erase commands, ERAL guarantees full-array readiness before WRAL execution - critical for safe firmware update rollback mechanisms.