Microchip Technology 93C56AT-I/ST

Overview

93C56AT-I/ST from Microchip Technology Inc. is a 2 Kbit (256 × 8-bit) low-voltage serial EEPROM with Microwire-compatible 3-wire interface, 4.5–5.5 V supply range, and Industrial temperature grade (−40°C to +85°C). It features self-timed erase/write cycles, automatic ERAL before WRAL, power-on/off data protection, and Ready/Busy status signaling via DO pin - used in embedded microcontroller systems for parameter storage and calibration data retention.

For engineers reviewing the 93C56AT-I/ST datasheet, 93C56AT-I/ST pinout, 93C56AT-I/ST application, or 93C56AT-I/ST equivalent, key selection considerations include its fixed 8-bit organization (no ORG pin), 2 ms typical write cycle time, TSSOP-8 package compatibility, and support for sequential read and WRAL/ERAL commands under ≥4.5 V operation.

Technical Context

The 93C56AT-I/ST implements a synchronous serial Microwire interface with CS, CLK, and DI/DO pins. Its internal architecture includes an address decoder, data register, mode decode logic, and output buffer - enabling opcode-driven operations including READ (20 CLK cycles), WRITE (20 CLK cycles), ERASE (12 CLK cycles), and WRAL (20 CLK cycles).

All programming operations require prior EWEN command execution and are inhibited when VCC falls below 3.8 V. The device powers up in EWDS mode and uses DO pin polling (low = busy, high = ready) to monitor erase/write progress without external timing dependencies.

Key Specifications

Pinout & Package

93C56AT-I/ST is supplied in an 8-pin TSSOP package (ST suffix), with 3.0 mm × 4.4 mm footprint and 0.65 mm pitch. Pin 1 is marked by laser dot; exposed pad is not present in TSSOP.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 93C56AT-I/SN and 93LC56BT-I/ST, the 93C56AT-I/ST offers optimal balance of compact TSSOP-8 packaging, fixed 8-bit compatibility, and guaranteed 4.5–5.5 V operation - making it ideal for cost-sensitive, space-limited industrial and automotive applications requiring proven reliability.

Availability

93C56AT-I/ST is available at Aetrix Electronics and suitable for industrial sensor calibration, automotive body control modules, and medical device configuration requiring stable component supply and long-term lifecycle support.

Supply support for 93C56AT-I/ST 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, serving industrial, automotive, and consumer markets with high-reliability silicon and development tools.

The 93C56A/B/C series was designed specifically for low-power, Microwire-compatible serial EEPROM applications where small footprint, robust data integrity, and wide supply voltage tolerance are critical - especially in resource-constrained embedded systems.

FAQ

What is the memory organization of the 93C56AT-I/ST?

The 93C56AT-I/ST has a fixed 256 × 8-bit organization. It belongs to the 'A' version family, meaning the ORG pin is not functional and is internally disconnected - eliminating configuration complexity and ensuring consistent 8-bit data transfers without external logic.

Does the 93C56AT-I/ST support 16-bit operation?

No, the 93C56AT-I/ST does not support 16-bit operation. As an 'A' version device, it is strictly 8-bit (256 × 8). For 16-bit capability, the 93C56BT-I/ST ('B' version) or 93C56CT-I/ST ('C' version with ORG pin) must be used - both require firmware and hardware changes to accommodate x16 addressing and data flow.

What is the minimum VCC required for ERAL and WRAL commands on the 93C56AT-I/ST?

The 93C56AT-I/ST requires VCC ≥ 4.5 V to execute ERAL (Erase All) and WRAL (Write All) commands reliably. This is specified in the datasheet's AC characteristics and functional description sections, and operation below this threshold will inhibit these commands regardless of instruction sequence.

How is Ready/Busy status monitored on the 93C56AT-I/ST?

Ready/Busy status is monitored by polling the DO pin while CS is high after being held low for ≥250 ns (TCSL). DO = low indicates ongoing erase/write; DO = high confirms completion. The status remains valid until the next Start condition is detected, and issuing a Start bit followed by CS low clears the status flag.

Is the ORG pin used on the 93C56AT-I/ST?

No, the ORG pin on the 93C56AT-I/ST is internally unconnected (NC) and must be left floating or tied to VSS. The 'A' suffix explicitly denotes fixed 8-bit organization, distinguishing it from 'B' (fixed 16-bit) and 'C' (pin-selectable) variants - no external logic or pull-up/down is needed or effective.