Microchip Technology 93LC86C-I/P

Overview

93LC86C-I/P from Microchip Technology is a 16 Kbit Microwire-compatible serial EEPROM with user-selectable 8-bit or 16-bit word organization via the ORG pin, program enable (PE) write protection, and industrial temperature range (–40°C to +85°C). It operates from 2.5V to 5.5V, supports 1 million erase/write cycles, and retains data for >200 years - used in embedded system configuration storage, sensor calibration memory, and power-management parameter retention.

For engineers reviewing the 93LC86C-I/P datasheet, 93LC86C-I/P pinout, 93LC86C-I/P application, or 93LC86C-I/P equivalent, key selection considerations include VCC voltage compatibility (2.5–5.5 V), ORG/PE pin control logic, Ready/Busy status polling via DO, and self-timed ERAL/WRAL operations requiring ≥4.5 V for full functionality.

Technical Context

The 93LC86C-I/P implements a synchronous 3-wire Microwire interface (CS, CLK, DI/DO) with dual-mode memory organization: ORG = VSS selects 2048 × 8-bit (x8), ORG = VCC selects 1024 × 16-bit (x16). It uses internal auto-erase before write and supports sequential read, ERAL (Erase All), and WRAL (Write All) commands.

Write protection is enforced by the PE pin: only when PE = VCC can EWEN be issued to enable programming; PE = VSS permanently inhibits all erase/write functions. The DO pin serves dual roles - data output during READ and Ready/Busy status indicator (low = busy) during erase/write cycles - requiring CS reassertion after TCSL ≥250 ns to sample status.

Key Specifications

Pinout & Package

Package: 8-lead PDIP (Plastic Dual In-line Package), Pb-free Matte Tin finish, through-hole mounting.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 93LC86C-I/P, the I/SN variant offers identical functionality in SOIC-8 for SMT use, while AT25160B-SSHL-T provides higher speed and SPI compatibility but removes ORG/PE-based hardware configurability and protection - trade-offs center on interface standardization versus pin-level control.

Availability

93LC86C-I/P is available at Aetrix Electronics and suitable for industrial automation, automotive subsystems, and medical device manufacturing requiring stable component supply, long-lifecycle assurance, and RoHS-compliant through-hole EEPROMs.

Supply support for 93LC86C-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 devices, and memory solutions, headquartered in Chandler, Arizona, with global design and manufacturing operations.

The 93LCxx family was designed specifically for cost-sensitive, low-power embedded systems needing reliable serial EEPROM with flexible organization and robust hardware write protection - targeting industrial controls, automotive modules, and consumer electronics.

FAQ

What is the function of the ORG pin on the 93LC86C-I/P?

The ORG pin on the 93LC86C-I/P selects memory organization: tied to VSS it configures the device as 2048 × 8-bit (x8), and tied to VCC it configures as 1024 × 16-bit (x16). This pin is absent on A/B variants and is essential for matching the host processor's data bus width. The 93LC86C-I/P requires a stable logic level on ORG before any instruction execution - floating is not permitted.

How does the PE pin protect memory on the 93LC86C-I/P?

The PE (Program Enable) pin on the 93LC86C-I/P acts as a hardware write gate: only when PE = VCC can the EWEN command be accepted to enable erase/write operations. If PE = VSS, all programming functions (EWEN, ERASE, WRITE, WRAL) are permanently disabled - even if valid opcodes are sent. This provides fail-safe protection against firmware errors or voltage transients. The 93LC86C-I/P datasheet mandates PE be hardwired, not driven dynamically.

What voltage is required for ERAL and WRAL commands on the 93LC86C-I/P?

Both ERAL (Erase All) and WRAL (Write All) commands on the 93LC86C-I/P require VCC ≥ 4.5 V for guaranteed operation, as specified in DS21797L-page 7 and page 10. At lower voltages (2.5–4.4 V), these commands may fail or produce undefined behavior. The 93LC86C-I/P's internal voltage detector does not block ERAL/WRAL below 4.5 V - compliance is the designer's responsibility. Other commands (READ, WRITE, EWEN) operate across the full 2.5–5.5 V range.

Can the 93LC86C-I/P be used with a shared DI/DO bus line?

Yes, the 93LC86C-I/P supports a single-wire bidirectional bus (DI/DO tied together), but requires a series resistor (typically 10 kΩ) to prevent bus conflict during the dummy zero bit of READ operations when A0 = high. Without the resistor, undefined voltage levels may occur at DO due to impedance mismatch. The 93LC86C-I/P's DO pin enters High-Z when CS is low or during non-read states, enabling safe bus sharing - however, timing margins tighten and noise immunity decreases versus separate lines.

What is the minimum CS low time between instructions for the 93LC86C-I/P?

The minimum Chip Select low time (TCSL) between consecutive instructions for the 93LC86C-I/P is 250 ns, as defined in Table 1-2 (A6) of DS21797L. This interval resets the internal state machine and ensures proper command isolation. Violating TCSL may cause instruction corruption or unintended multi-command execution. The 93LC86C-I/P does not require CS to go fully inactive between READ cycles during sequential read mode - CS may remain high while CLK continues.