Microchip Technology 93C56-I/SM

Overview

93C56-I/SM from Microchip Technology is a 2K-bit serial EEPROM organized as 128 x 16 or 256 x 8, featuring Microwire-compatible 3-wire serial interface, 5.5 V max operating voltage, and industrial temperature range (–40°C to +85°C). It serves as nonvolatile configuration memory in embedded controllers and power management circuits.

For engineers reviewing the 93C56-I/SM datasheet, 93C56-I/SM pinout, 93C56-I/SM application, or 93C56-I/SM equivalent, key selection criteria include write endurance (1M cycles), data retention (200 years), and compatibility with legacy Microwire-based host controllers in space-constrained industrial modules.

Technical Context

The 93C56-I/SM implements a synchronous serial interface with CS, SK, DI, and DO pins, supporting both 8-bit and 16-bit word organization selectable via ORG pin state. Internal address counter auto-increments during sequential reads, and write operations require explicit Write Enable (WEN) command followed by 10 ms typical erase/write cycle time.

It uses CMOS process technology with on-chip charge pump for internal high-voltage generation during write/erase, eliminating need for external V_PP. Data protection includes software write protection (via EWDS/EWEN commands) and hardware write protection (WP pin active-low).

Key Specifications

Pinout & Package

93C56-I/SM is housed in an 8-lead SOIC (Small Outline Integrated Circuit) package with 150 mil body width and standard gull-wing lead form.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 93C56-I/SM, the 93C56-E/MS offers smaller footprint at the cost of thermal performance, while AT93C56-10SU-2.7 provides identical functionality with relaxed voltage and temperature specs - enabling trade-offs between reliability, size, and cost.

Availability

93C56-I/SM is available at Aetrix Electronics and suitable for industrial sensor calibration, legacy MCU configuration storage, and power supply trim settings requiring stable component supply across long-lifecycle programs.

Supply support for 93C56-I/SM 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 is a U.S.-based semiconductor company specializing in microcontrollers, analog devices, and memory products for embedded control applications.

The 93Cxx family was designed specifically for reliable, low-pin-count serial configuration storage in resource-constrained microcontroller systems, emphasizing Microwire compatibility and industrial temperature resilience.

FAQ

What is the maximum clock frequency supported by the 93C56-I/SM?

The 93C56-I/SM supports a maximum serial clock (SK) frequency of 2 MHz at V_CC ≥ 4.5 V, and 1 MHz at V_CC = 2.5 V. This ensures reliable communication with legacy Microwire hosts while maintaining timing margins across voltage and temperature extremes. The 93C56-I/SM datasheet specifies setup/hold times referenced to SK edges, and these limits are validated per MCHPS04505-1.

Does the 93C56-I/SM require an external high-voltage supply for write operations?

No, the 93C56-I/SM integrates an on-chip charge pump that generates the necessary programming voltage internally. This eliminates the need for an external V_PP pin or high-voltage generator circuit. All write and erase functions operate from the standard V_CC supply (2.5–5.5 V), simplifying system design and reducing BOM count. The 93C56-I/SM achieves this using proprietary CMOS process enhancements documented in Microchip's MCHPS04505-1 specification.

How is memory organization selected on the 93C56-I/SM?

Memory organization (128 × 16 or 256 × 8) is determined by the logic level on the ORG pin at power-up: ORG = high selects 128 × 16 mode, ORG = low selects 256 × 8 mode. This configuration is latched internally and remains fixed until next power cycle. The 93C56-I/SM does not support dynamic reconfiguration - the setting must match host controller expectations before initialization.

Can the 93C56-I/SM be used as a direct replacement for the 93C46?

No, the 93C56-I/SM is not a direct replacement for the 93C46 due to differences in memory size (2 Kbit vs. 1 Kbit) and instruction set - the 93C56-I/SM requires extended address bits and supports additional commands like EWDS/EWEN. While pinout and interface are compatible, firmware must be updated to handle larger address space and enhanced protection features. The 93C56-I/SM is backward-compatible only with other 93C56 variants.

What write protection mechanisms does the 93C56-I/SM provide?

The 93C56-I/SM implements dual write protection: hardware-level via the WP pin (active-low, disables all writes when asserted), and software-level via EWDS (Erase/Write Disable Status) and EWEN (Erase/Write Enable) instructions. These allow selective locking of memory regions independent of WP state. Both mechanisms are fully documented in the 93C56-I/SM datasheet (MCHPS04505-1) and operate concurrently to prevent accidental or malicious overwrites.