Microchip Technology 93LC46B/P

Overview

93LC46B/P from Microchip Technology Inc. is a 1Kbit (64 × 16-bit) low-voltage serial EEPROM with Microwire-compatible 3-wire interface, 2.5–5.5 V supply range, and industrial temperature support (–40°C to +85°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 for nonvolatile parameter storage in microcontroller-based embedded systems requiring reliable, low-power memory.

For engineers reviewing the 93LC46B/P datasheet, 93LC46B/P pinout, 93LC46B/P application, or 93LC46B/P equivalent, key selection considerations include its fixed 16-bit organization (no ORG pin), PDIP-8 package compatibility, 3 MHz max clock frequency at 4.5–5.5 V, 6 ms typical write cycle time, and RoHS-compliant matte tin finish.

Technical Context

The 93LC46B/P implements a synchronous serial Microwire protocol with CS, CLK, and DI/DO lines - no ORG pin required, as it is permanently configured for 16-bit word access. All instructions (READ, WRITE, ERASE, ERAL, WRAL, EWEN/EWDS) are initiated by a Start bit followed by opcode, address, and data bits clocked on CLK rising edges.

It uses CMOS EEPROM technology with auto-erase-before-write architecture, enabling single-cycle programming without external erase commands. The DO pin serves dual function: serial data output during READ and Ready/Busy status indicator during erase/write operations, with high-Z state when inactive or deselected.

Key Specifications

Pinout & Package

93LC46B/P is supplied in an 8-lead plastic dual in-line package (PDIP), with lead finish matte tin (Pb-free). Pin 1 is marked by laser dot or notch; pin 1 ID orientation follows JEDEC standard.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 93LC46B/SN, the 93LC46B/P offers identical functionality in through-hole form for prototyping and legacy board upgrades; versus AT25010B-PU, it retains Microwire compatibility and hardware-ready signaling but trades higher clock speed for simpler timing constraints.

Availability

93LC46B/P is available at Aetrix Electronics and suitable for smart meter calibration storage, industrial PLC configuration memory, and automotive body control module applications requiring stable component supply, long-lifecycle assurance, and RoHS-compliant through-hole packaging.

Supply support for 93LC46B/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 components, and memory solutions, headquartered in Chandler, Arizona, with global design and manufacturing operations.

The 93LC46B/P belongs to Microchip's legacy 93XX serial EEPROM product line, designed specifically for cost-sensitive, low-power embedded systems requiring simple, reliable nonvolatile storage with minimal pin count and firmware overhead.

FAQ

What is the memory organization of the 93LC46B/P?

The 93LC46B/P has a fixed 64-word × 16-bit (1 Kbit) organization. Unlike 'C' variants, it does not feature an ORG pin - the 16-bit word width is hardwired, eliminating external configuration logic and simplifying host interface design for systems requiring native 16-bit parameter storage.

Does the 93LC46B/P require an external pull-up resistor on the DO pin?

No - the 93LC46B/P drives DO actively during READ and Ready/Busy status reporting. However, a 10 kΩ pull-down on CS is recommended per Microchip's design guidance to prevent spurious start conditions during power-up or noise events, ensuring robust operation of the 93LC46B/P in electrically noisy environments.

What is the maximum clock frequency supported by the 93LC46B/P?

The 93LC46B/P supports up to 3 MHz clock frequency when VCC is 4.5 V to 5.5 V. At lower voltages (2.5–4.5 V), the maximum clock rate drops to 2 MHz. These limits are defined in Table 1-2 AC Characteristics and ensure reliable setup/hold timing for all instructions executed on the 93LC46B/P.

How does the 93LC46B/P handle power loss during a write operation?

The 93LC46B/P incorporates hardware-level power-loss protection: if VCC falls below ~1.5 V during erase/write, the internal circuitry halts the cycle and preserves existing data. No partial writes occur. This behavior is intrinsic to the 93LC46B/P's design and requires no external capacitors or firmware intervention.

Is the 93LC46B/P pin-compatible with other 93XX46 devices in PDIP-8 package?

Yes - the 93LC46B/P shares identical PDIP-8 pinout and signal definitions with all 93XX46A/B/C variants in the P package, including 93AA46B/P and 93C46B/P. However, voltage ranges and temperature grades differ: 93LC46B/P operates from 2.5–5.5 V and supports Industrial temp, while 93C46B/P requires 4.5–5.5 V.