Microchip Technology 93LC56-I/P

Overview

93LC56-I/P from Microchip Technology Inc. is a 2 Kbit serial EEPROM with Microwire-compatible 3-wire interface, configurable as 256 × 8 or 128 × 16 organization via ORG pin, rated for industrial temperature (−40°C to +85°C), and packaged in 8-pin PDIP. It supports single-supply operation down to 2.5 V and delivers 1,000,000 erase/write cycles with >200-year data retention - used for nonvolatile parameter storage in embedded control systems.

For engineers reviewing the 93LC56-I/P datasheet, 93LC56-I/P pinout, 93LC56-I/P application, or 93LC56-I/P equivalent, this page provides verified functional identity, validated pin-level timing behavior, confirmed memory organization flexibility, and real-world design constraints including ORG pin voltage dependency, CS/CLK setup/hold requirements, and self-timed write cycle duration.

Technical Context

The 93LC56-I/P implements a synchronous serial Microwire interface with start-bit detection, opcode-driven command set (READ, WRITE, ERASE, EWEN/EWDS, ERAL/WRAL), and status polling via DO pin during programming. Memory access is controlled by CS activation, CLK-synchronized bit shifting on DI, and output toggling on DO aligned to CLK rising edge.

Its dual-organization architecture relies on static ORG pin logic level (VCC = x16, VSS = x8) to define address width and data bus size; floating ORG is only permitted ≤1 MHz in x16 mode. Power-on protection inhibits programming until VCC ≥1.4 V, and EWEN must precede all erase/write operations.

Key Specifications

Pinout & Package

8-pin Plastic Dual In-line Package (PDIP), 300 mil body width, JEDEC MS-001 compliant. Pin 1 is CS; pin 8 is VCC; pin 5 is VSS; pin 6 is ORG; pins 7 and 1–4 follow standard Microwire pinout.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 93LC56-I/P, the 93LC56-I/SN offers identical functionality in a surface-mount package ideal for volume manufacturing, while the 93LC56C-I/P provides higher reliability and updated qualification - making it the recommended upgrade path for new designs where long-term supply continuity and enhanced robustness are critical.

Availability

93LC56-I/P is available at Aetrix Electronics and suitable for industrial sensor calibration storage, consumer appliance configuration, and automotive body control module applications requiring stable component supply and long-term obsolescence management.

Supply support for 93LC56-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 microcontroller, analog, and memory solutions, headquartered in Chandler, Arizona, with global design, manufacturing, and sales operations.

The 93LC56-I/P belongs to Microchip's legacy Microwire EEPROM product line, designed specifically for cost-sensitive, low-pin-count embedded systems requiring simple, robust nonvolatile storage without complex protocol stacks.

FAQ

What memory organization options does the 93LC56-I/P support?

93LC56-I/P supports two memory organizations selected by the ORG pin: 256 × 8 bits (ORG = VSS) or 128 × 16 bits (ORG = VCC). The device uses different address widths (8-bit vs. 9-bit) and data widths accordingly. Floating ORG is permitted only at clock frequencies ≤1 MHz in x16 mode. This flexibility allows one 93LC56-I/P design to serve both 8-bit and 16-bit host systems without changing firmware or layout.

How does the 93LC56-I/P indicate readiness after an erase or write operation?

The 93LC56-I/P signals readiness via the DO pin: logical low indicates ongoing erase/write, and logical high confirms completion. To poll status, CS must be brought high for ≥250 ns after the initial falling edge that started the cycle. A pull-up resistor on DO is required to reliably read the high state. This mechanism eliminates the need for fixed software delays and adapts to process/voltage/temperature variations affecting actual cycle time.

What is the minimum supply voltage required for reliable operation of the 93LC56-I/P?

The 93LC56-I/P operates reliably from 2.5 V to 5.5 V. At 2.5 V, typical active read current is 100 µA and standby current is 3 µA. Programming functions (erase/write) are fully specified down to 2.5 V, though write cycle time increases slightly versus 5 V operation. Below 2.5 V, the internal voltage monitor disables all programming modes to prevent data corruption - a hardware safeguard independent of software control.

Is the 93LC56-I/P pin-compatible with other devices in the 93LCxx family?

Yes - the 93LC56-I/P shares identical pinout, interface timing, and instruction set with 93LC46-I/P and 93LC66-I/P in PDIP packages. All three use the same 8-pin layout (CS, CLK, DI, DO, VSS, ORG, NU, VCC) and support ORG-selectable x8/x16 organization. However, memory depth differs: 1K (93LC46), 2K (93LC56), and 4K (93LC66). Firmware must validate address range to avoid wraparound errors when substituting.

What protection mechanisms prevent accidental writes to the 93LC56-I/P?

The 93LC56-I/P employs three hardware-based protections: (1) Power-on/off voltage monitoring that disables programming below 1.4 V; (2) Erase/Write Enable (EWEN) command required before any erase/write - device powers up in EWDS (disabled) state; (3) No-write condition if CS remains high beyond TCSL without valid start-bit detection. These features eliminate need for external write-protect pins or software locks in most implementations.