Microchip Technology 93C86C-E/SN

Overview

The 93C86C-E/SN from Microchip Technology Inc. is a 16 Kbit Microwire-compatible serial EEPROM with configurable 8-/16-bit word organization, Program Enable (PE) write-protection, and industrial/automotive temperature support (–40°C to +125°C). It operates from 4.5V to 5.5V, delivers 1 million erase/write cycles, retains data >200 years, and integrates Ready/Busy status signaling via DO pin - used in automotive body control modules for calibration storage.

For engineers reviewing the 93C86C-E/SN datasheet, 93C86C-E/SN pinout, 93C86C-E/SN application, or 93C86C-E/SN equivalent, key selection considerations include ORG-pin-configurable memory width, PE-enabled hardware write lockout, VCC-dependent ERAL/WRAL timing (≥4.5V), self-timed erase/write (2 ms), and compatibility with legacy Microwire controllers in space-constrained automotive PCBs.

Technical Context

The 93C86C-E/SN implements a synchronous 3-wire Microwire interface (CS/CLK/DI/DO) with start-bit detection and opcode-driven command execution. Its dual-word-size capability is controlled solely by the ORG pin level (VCC = x16, VSS = x8), and all programming operations require prior EWEN activation followed by PE = high.

Internal auto-erase precedes every WRITE or WRAL operation, and ERAL/WRAL are fully self-timed (6 ms and 15 ms respectively at 4.5–5.5V). The DO pin serves dual function: serial data output during READ and active-low Ready/Busy status polling during erase/write cycles - eliminating need for external status registers.

Key Specifications

Pinout & Package

Package: 8-lead SOIC (SN), Pb-free Matte Tin finish, 150 mil width, JEDEC MS-012AC compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 93LC86C-E/SN and AT25128B-MAHL-T, the 93C86C-E/SN uniquely combines automotive-grade temperature support, hardware-programmable word width, and dedicated write-enable pin - making it optimal for safety-critical, voltage-stable 5V automotive subsystems requiring deterministic timing and robust data protection.

Availability

The 93C86C-E/SN is available at Aetrix Electronics and suitable for automotive body control units, industrial PLC configuration storage, and medical infusion pump calibration requiring stable component supply across extended temperature ranges and long product lifecycles.

Supply support for 93C86C-E/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 microcontroller, analog, and Flash-IP solutions, serving automotive, industrial, and consumer markets with high-reliability silicon and development tools.

The 93C86C-E/SN belongs to Microchip's legacy 93XX serial EEPROM family, designed specifically for cost-sensitive, space-constrained applications requiring proven Microwire compatibility, hardware-based data protection, and AEC-Q100-aligned automotive qualification.

FAQ

What is the minimum VCC required for reliable operation of the 93C86C-E/SN?

The 93C86C-E/SN has a power-on reset (POR) threshold of 3.8V. Operation below this voltage inhibits all functions including read, write, and status polling. Stable operation requires VCC ≥4.5V per datasheet specifications, and the device will not execute ERAL or WRAL unless VCC is maintained at ≥4.5V throughout the cycle. This ensures robust behavior in automotive battery-sensing applications where brown-out conditions must be strictly avoided.

How does the ORG pin affect memory addressing in the 93C86C-E/SN?

When ORG = VCC, the 93C86C-E/SN configures as 1024 × 16-bit (x16), requiring 10-bit addresses (A9–A0) and accepting 16-bit data words. When ORG = VSS, it configures as 2048 × 8-bit (x8), requiring 11-bit addresses (A10–A0) and 8-bit data. The instruction set and opcode decoding change accordingly - confirmed in Tables 1-3 and 1-4 of DS21797L. This is a hardware-level configuration; no software register controls it.

Is the 93C86C-E/SN pin-compatible with earlier 93C86A or 93C86B variants?

No - the 93C86C-E/SN includes dedicated ORG and PE pins (pins 6 and 7), whereas 93C86A/B omit these pins entirely and use fixed 8-bit or 16-bit organization. In SOIC-8 (SN) package, pin 6 and pin 7 are NC on 93C86A/B but functional on 93C86C-E/SN. PCB layout must allocate those pins; direct replacement would cause functional failure due to missing hardware write protection and unconfigured word size.

What happens if the PE pin is left floating on the 93C86C-E/SN?

The PE pin must never be left floating: Section 3.6 explicitly states it "cannot be floated, it must be tied to VCC or VSS." A floating PE creates undefined programming behavior - potentially allowing partial or corrupted writes during noise events. For fail-safe operation, tie PE to VSS (write-disabled default) and assert VCC only during intentional programming sequences, consistent with automotive ASIL-B design practices.

Does the 93C86C-E/SN support sequential read mode, and how is it enabled?

Yes - sequential read is supported and enabled automatically when CS remains high across consecutive READ instructions. After outputting the first addressed byte/word, the internal address counter increments, and subsequent clock edges shift out the next location's data without retransmitting address bits. This reduces bus overhead and is confirmed in Section 2.7 ("Read") and Figure 2-5. No command or setup is required beyond holding CS active.