Microchip Technology 93LC56C-I/SN

Overview

93LC56C-I/SN from Microchip Technology 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 - used for parameter storage in embedded microcontroller systems.

For engineers reviewing the 93LC56C-I/SN datasheet, 93LC56C-I/SN pinout, 93LC56C-I/SN application, or 93LC56C-I/SN 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 SOIC-8 packaging.

Technical Context

The 93LC56C-I/SN implements a synchronous Microwire-compatible serial protocol with start-bit detection, opcode-driven instruction set (READ, WRITE, ERASE, ERAL, WRAL, EWEN/EWDS), and dual-organization memory array selectable by external logic level on ORG. Its internal state machine manages auto-erase-before-write and full-array operations without host timing intervention.

Power-on data protection is enforced by VCC voltage detect (1.5 V threshold), and programming is disabled by default (EWDS mode) until explicitly enabled via EWEN. The DO pin serves dual function: serial data output during READ and active-low Ready/Busy indicator during erase/write - requiring CS high ≥250 ns after TCSL to sample status.

Key Specifications

Pinout & Package

Package: 8-lead SOIC (SN), Pb-free Matte Tin finish, body dimensions 3.9 mm × 4.9 mm × 1.75 mm.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 93LC56B-I/SN and AT25020B-MAHL-T, the 93LC56C-I/SN uniquely balances hardware configurability (via ORG) with Microwire simplicity and industrial-grade reliability - making it optimal for cost-sensitive, mixed-bus embedded designs where pin count and protocol compatibility are constrained.

Availability

93LC56C-I/SN is available at Aetrix Electronics and suitable for industrial automation, automotive subsystems, and medical device manufacturing requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant packaging.

Supply support for 93LC56C-I/SN 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.

The 93LC56C belongs to Microchip's legacy 93XX serial EEPROM family, designed specifically for low-power, pin-efficient nonvolatile storage in resource-constrained embedded systems where Microwire compatibility and robust data integrity are essential.

FAQ

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

The ORG pin on the 93LC56C-I/SN selects memory organization: logic high (VCC) configures 128 × 16-bit mode, logic low (VSS) configures 256 × 8-bit mode. Unlike A/B variants, the 93LC56C-I/SN requires this pin to be externally biased - it is not NC. This enables one PCB design to support both 8-bit and 16-bit MCU interfaces without changing the 93LC56C-I/SN footprint or firmware logic.

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

The 93LC56C-I/SN uses the DO pin for Ready/Busy status: DO outputs low during erase/write cycles and goes high when complete. To poll status, CS must be brought high for ≥250 ns after TCSL (minimum CS low time); DO then reflects device state. After completion, issuing a Start bit followed by CS low clears the status flag. This mechanism is integral to the 93LC56C-I/SN's self-timed operation.

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

At VCC = 3.3 V (within 2.5–5.5 V range), the 93LC56C-I/SN supports up to 2 MHz clock frequency, as specified in Table 1-2 (A1, FCLK). This is lower than its 3 MHz maximum at 4.5–5.5 V but sufficient for most parameter storage tasks in 3.3 V MCU systems. Timing margins remain compliant down to 1.8 V for compatible variants, but the 93LC56C-I/SN's minimum VCC is 2.5 V.

Does the 93LC56C-I/SN require an external pull-up resistor on the DO line?

No, the 93LC56C-I/SN does not require an external pull-up on DO. Its output buffer actively drives high/low during READ and Ready/Busy states, and enters High-Z when inactive. However, if DI and DO are shorted (common-bus configuration), a series resistor (e.g., 10 kΩ) is recommended to prevent bus conflict when A0 is high during the dummy zero phase of READ - a design consideration specific to the 93LC56C-I/SN's protocol behavior.

What packaging and marking identify the 93LC56C-I/SN variant?

The 93LC56C-I/SN uses an 8-lead SOIC package (SN suffix), industrial temperature grade (I), and is marked "L56C" in first-line marking per DS21794G-page 14. The "SN" in the part number explicitly denotes SOIC packaging; "I" confirms –40°C to +85°C operation; and the "C" suffix identifies the ORG-pin-configurable version - distinguishing it from fixed-organization 93LC56A-I/SN (8-bit only) and 93LC56B-I/SN (16-bit only).