Microchip Technology 93LC56C-I/P

Overview

93LC56C-I/P from Microchip Technology Inc. is a 2 Kbit low-voltage serial EEPROM with configurable 8-/16-bit word organization via the ORG pin, 2.5–5.5 V supply range, and industrial temperature rating (–40°C to +85°C). It features Microwire-compatible 3-wire serial interface, self-timed erase/write cycles, automatic ERAL before WRAL, and 1,000,000 endurance cycles - deployed in embedded microcontroller systems for parameter storage and calibration data retention.

For engineers reviewing the 93LC56C-I/P datasheet, 93LC56C-I/P pinout, 93LC56C-I/P application, or 93LC56C-I/P equivalent, key selection criteria include ORG-pin-configurable memory width, VCC-dependent clock frequency (up to 3 MHz at 4.5–5.5 V), Ready/Busy status polling via DO, write cycle time (6 ms), and Pb-free PDIP package compatibility with legacy through-hole designs.

Technical Context

The 93LC56C-I/P implements a synchronous Microwire-compatible serial interface with CS, CLK, DI, and DO signals plus dedicated ORG pin for runtime memory width selection (x8 when ORG = VSS, x16 when ORG = VCC). Its internal logic supports instruction decoding for READ, WRITE, ERASE, ERAL, WRAL, EWEN, and EWDS - all initiated by rising-edge clocked bit streams starting with a Start condition (CS high & DI high).

Power-on data protection is enforced by voltage-detect circuitry (VPOR = 1.5 V typical), and programming operations require explicit EWEN command prior to any erase/write. The device enters Standby mode when CS is low, drawing only 1 µA (I-temp), and asserts Ready/Busy status on DO during active programming - enabling non-blocking host control without fixed delay timing.

Key Specifications

Pinout & Package

93LC56C-I/P is supplied in an 8-lead plastic dual in-line package (PDIP), with lead finish Matte Tin (Pb-free, RoHS compliant). Pin 1 is marked by laser dot; pin 1 ID orientation follows standard DIP convention (notch-left, pin 1 top-left).

Key Features

Applications

Equivalent & Alternatives

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

Compared with 93LC56B-I/P, the 93LC56C-I/P offers runtime word-width reconfiguration; compared with AT25020B-MAHL-T, it provides lower pin count and hardware-ready/busy signaling at the cost of slower maximum clock rate and Microwire-only compatibility.

Availability

93LC56C-I/P is available at Aetrix Electronics and suitable for industrial sensor calibration, consumer appliance configuration, and automotive body control modules requiring stable component supply across extended production lifecycles.

Supply support for 93LC56C-I/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, FPGA, and memory solutions, headquartered in Chandler, Arizona.

The 93LC56C-I/P belongs to Microchip's legacy 93XX serial EEPROM family, designed specifically for cost-sensitive, low-power embedded systems requiring simple, robust nonvolatile storage with minimal MCU resource usage.

FAQ

What is the function of the ORG pin on the 93LC56C-I/P?

The ORG pin on the 93LC56C-I/P selects memory organization: logic high (VCC) configures 128 × 16-bit mode, logic low (VSS) configures 256 × 8-bit mode. This pin must be externally biased - floating is not permitted. Unlike 93LC56A/B variants, the 93LC56C-I/P requires this pin to be connected to define word width at power-up, enabling one hardware design to serve multiple MCU data bus widths without redesign.

Does the 93LC56C-I/P support SPI communication?

No, the 93LC56C-I/P does not support SPI. It implements a Microwire-compatible 3-wire serial interface (CS, CLK, DI/DO) with specific instruction opcodes and timing - distinct from SPI's 4-wire protocol (CS, SCK, MOSI, MISO) and frame structure. While both are synchronous serial, firmware drivers for SPI cannot be reused; dedicated Microwire bit-banging or peripheral support is required for the 93LC56C-I/P.

What is the maximum clock frequency supported by the 93LC56C-I/P at 3.3 V?

At VCC = 3.3 V (within 2.5–5.5 V range), the 93LC56C-I/P supports a maximum clock frequency of 2 MHz, as specified in Table 1-2 (A1: FCLK). This limit applies across industrial temperature range (–40°C to +85°C). Exceeding 2 MHz at 3.3 V risks setup/hold violations and unreliable instruction execution - verified by AC characterization, not extrapolated from higher-voltage specs.

How does the 93LC56C-I/P indicate readiness after a write operation?

The 93LC56C-I/P indicates readiness after a write operation by driving the DO pin high when polled. After initiating WRITE or WRAL, the host must wait ≥250 ns with CS low (TCSL), then bring CS high and monitor DO: low = busy, high = ready. This Ready/Busy status is valid only when CS is high and replaces fixed-delay waits - a key feature distinguishing the 93LC56C-I/P from simpler EEPROMs lacking status feedback.

Is the 93LC56C-I/P pin-compatible with the 93LC56A-I/P?

No, the 93LC56C-I/P is not pin-compatible with the 93LC56A-I/P. Although both use the same 8-lead PDIP package and share CS, CLK, DI, DO, VSS, VCC, and NC pin assignments, the 93LC56C-I/P uses pin 6 for ORG (active function), whereas the 93LC56A-I/P has NC (no internal connection) at pin 6. Direct substitution would leave ORG unconnected on the 'C' variant, causing undefined memory organization - requiring PCB layout change or external biasing modification.