Microchip Technology 93C56B-I/P

Overview

93C56B-I/P from Microchip Technology Inc. is a 2 Kbit (128 × 16-bit) low-voltage serial EEPROM with Microwire-compatible 3-wire interface, 4.5–5.5 V supply range, and industrial temperature rating (–40°C to +85°C). It features self-timed erase/write cycles, automatic ERAL before WRAL, and Ready/Busy status via DO pin. Used in microcontroller-based systems for parameter storage, calibration data retention, and configuration memory.

For engineers reviewing the 93C56B-I/P datasheet, 93C56B-I/P pinout, 93C56B-I/P application, or 93C56B-I/P equivalent, key selection criteria include its fixed 16-bit organization (no ORG pin), 2 ms write cycle time, 1 million endurance cycles, 200-year data retention, and compatibility with legacy Microwire controllers in space-constrained industrial designs.

Technical Context

The 93C56B-I/P implements a synchronous serial interface with CS, CLK, and DI/DO pins - no ORG pin present, confirming fixed x16 organization. Its command set includes READ (20 CLK cycles), WRITE (20 CLK cycles), ERASE (12 CLK cycles), ERAL (12 CLK cycles), and WRAL (20 CLK cycles), all initiated by rising-edge clocking of opcodes and addresses.

Write operations are self-timed and triggered by the rising edge of CLK on the final data bit (93C-series behavior), not CS falling edge. Power-on protection activates below 3.8 V, and EWEN/EWDS commands enforce explicit write-enable control - the device powers up in EWDS mode, requiring EWEN before any programming.

Key Specifications

Pinout & Package

8-lead PDIP package (P suffix), body width 0.300", lead pitch 0.100". Pin 1 marked by notch or dot; pin 1 ID confirmed per DS21794G-page 17.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 93LC56B-I/P, the 93C56B-I/P offers tighter V_CC tolerance and simpler power design but excludes extended temperature capability; versus AT25020B-MAHL-T, it provides deterministic status feedback and Microwire legacy compatibility at the cost of interface flexibility.

Availability

93C56B-I/P is available at Aetrix Electronics and suitable for industrial sensor calibration, legacy MCU configuration storage, and automotive subsystem identity applications requiring stable component supply, long-lifecycle support, and RoHS-compliant packaging.

Supply support for 93C56B-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 93Cxx series was designed specifically for cost-sensitive, low-power serial EEPROM applications in industrial and automotive systems where Microwire compatibility, proven reliability, and long-term data retention are essential.

FAQ

What is the memory organization of the 93C56B-I/P?

The 93C56B-I/P has a fixed 128 × 16-bit (2 Kbit) organization. Unlike 'C' variants, it lacks an ORG pin - confirming dedicated 16-bit operation. This eliminates external configuration logic and simplifies firmware address handling for word-aligned data structures. The 93C56B-I/P does not support 8-bit mode switching.

Does the 93C56B-I/P require an external pull-up resistor on the DO pin?

No, the 93C56B-I/P does not require an external pull-up on DO. The DO pin actively drives high/low during READ and Ready/Busy status reporting, and enters High-Z when deselected or idle. A pull-up may cause bus contention if DI and DO are shorted; Microchip recommends a series resistor if shared-bus configuration is used.

What is the minimum V_CC required for reliable operation of the 93C56B-I/P?

The 93C56B-I/P incorporates a power-on reset (POR) circuit that inhibits all operations until V_CC reaches 3.8 V. Below this threshold, the device remains in reset state - preventing spurious writes or corrupted reads during power ramp-up. Full specification compliance requires V_CC ≥4.5 V.

How is the write cycle initiated on the 93C56B-I/P?

On the 93C56B-I/P, the write cycle is initiated by the rising edge of CLK on the final data bit - not by CS falling edge (which applies to 93AA/93LC variants). This timing distinction is critical for firmware implementation: the controller must ensure CLK rises after the 16th data bit is latched, then wait for TWC (2 ms) before issuing next command.

Can the 93C56B-I/P be used in place of the 93C56A-I/P?

No - the 93C56B-I/P and 93C56A-I/P differ fundamentally in memory organization: 93C56B-I/P is 128 × 16-bit, while 93C56A-I/P is 256 × 8-bit. Firmware addressing, data packing, and instruction timing (e.g., READ requires 20 vs. 20 CLK cycles but different address width) are incompatible. Direct substitution will cause data misalignment and functional failure.