Microchip Technology 93C66AT-E/MNY

Overview

93C66AT-E/MNY from Microchip Technology Inc. is a 4 Kbit (512 × 8-bit) low-voltage serial EEPROM with Microwire-compatible 3-wire interface, 4.5–5.5 V supply range, and industrial-temperature operation (–40°C to +85°C). It features self-timed erase/write cycles, automatic ERAL/WRAL support, and power-on/off data protection - used in embedded system configuration storage, sensor calibration memory, and firmware parameter retention.

For engineers reviewing the 93C66AT-E/MNY datasheet, 93C66AT-E/MNY pinout, 93C66AT-E/MNY application, or 93C66AT-E/MNY equivalent, key selection criteria include its fixed 8-bit organization (no ORG pin), 2 ms write cycle time, 1 million endurance cycles, and compatibility with legacy Microwire controllers in space-constrained industrial modules.

Technical Context

This device implements a synchronous serial interface with CS, CLK, and DI/DO pins, operating exclusively in x8 mode due to absence of ORG functionality (confirmed for 'A' variant). All instructions - READ, WRITE, ERASE, ERAL, WRAL - are initiated via rising-edge clocked bit sequences starting with a Start bit (CS high + DI high).

Write operations are auto-erased and self-timed: for 93C66A/B/C variants, the rising edge of CLK on the final data bit triggers the internal 2 ms programming cycle. Ready/Busy status is polled via DO pin after CS reassertion, with TSV ≤ 500 ns at 1.8 V and ≤ 200 ns at 4.5–5.5 V.

Key Specifications

Pinout & Package

93C66AT-E/MNY is housed in an 8-lead 2×3 mm DFN (Dual Flat No-lead) package with exposed pad, Pb-free Matte Tin finish. Pin 1 is marked by laser dot; exposed pad may be connected to VSS or left floating per Microchip packaging spec.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 93LC66AT-I/MNY, the 93C66AT-E/MNY offers tighter 5 V timing margins and higher noise immunity but sacrifices low-voltage operation; versus AT25040B-MAHL-T, it retains legacy Microwire compatibility and integrated array-level erase functions at the cost of interface flexibility.

Availability

93C66AT-E/MNY is available at Aetrix Electronics and suitable for industrial sensor calibration storage, motor drive fault logging, and energy meter firmware parameter banking requiring stable component supply across extended product lifecycles.

Supply support for 93C66AT-E/MNY 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, serving industrial, automotive, and consumer markets globally.

The 93CXX series was designed specifically for cost-sensitive, space-constrained embedded systems requiring robust, low-pin-count serial EEPROM with Microwire compatibility and guaranteed 5 V operation.

FAQ

What is the memory organization of the 93C66AT-E/MNY?

The 93C66AT-E/MNY is a fixed 512 × 8-bit (4 Kbit) EEPROM with no ORG pin - it operates exclusively in x8 mode. Unlike 'C' variants, it does not support x16 configuration. This simplifies PCB layout and firmware driver design by eliminating external ORG pin biasing requirements. The 93C66AT-E/MNY maintains full instruction set compatibility with other 93C66A devices.

Does the 93C66AT-E/MNY support the WRAL (Write All) command?

Yes, the 93C66AT-E/MNY fully supports the WRAL command, which writes the entire 512-byte memory array with a single data value. WRAL automatically executes ERAL first, requires VCC ≥ 4.5 V, and completes in 15 ms. The command is only enabled after issuing EWEN; DO pin indicates Ready/Busy status. This function is confirmed in DS21795E Section 2.9 and Table 1-4.

What is the maximum clock frequency supported by the 93C66AT-E/MNY?

The 93C66AT-E/MNY supports up to 3 MHz clock frequency when VCC is 4.5–5.5 V (Table 1-2, A1). At this rate, READ requires 20 clock cycles (≈6.7 µs), and WRITE requires 20 cycles plus 2 ms internal programming. Timing parameters including TCKH (≥200 ns), TCKL (≥100 ns), and TDIS (≥50 ns) are fully characterized for 5 V operation.

Is the 93C66AT-E/MNY pin-compatible with other 93C66x variants in the same package?

Yes - the 93C66AT-E/MNY shares identical 8-lead DFN pinout and electrical characteristics with all 93C66A/B/C variants in the MNY package (e.g., 93C66BT-E/MNY, 93C66CT-E/MNY). Pin functions (CS, CLK, DI, DO, VSS, NC, VCC, NC) are identical; ORG is NC on all 'A' versions. Mechanical dimensions and solder profile match per Microchip Package Drawing 25016C.

How does the power-on data protection work in the 93C66AT-E/MNY?

The 93C66AT-E/MNY incorporates hardware voltage detection with a 3.8 V threshold (D11, Table 1-1). When VCC drops below this level, all write/erase operations are inhibited - preventing corruption during power ramp-up/down or brown-out conditions. This feature operates independently of firmware and requires no external components, ensuring data integrity in unregulated 5 V systems.