Microchip Technology 24C00T-I/ST

Overview

24C00T-I/ST from Microchip Technology Inc. is a 128-bit (16 × 8) I²C-compatible serial EEPROM designed for low-overhead nonvolatile storage of calibration data, device IDs, and manufacturing traceability in space-constrained industrial systems. It operates strictly within 4.5–5.5 V, supports −40°C to +85°C industrial temperature range, features Schmitt-trigger inputs, and delivers typical standby current of 100 nA and read current of 500 µA.

For engineers reviewing the 24C00T-I/ST datasheet, 24C00T-I/ST pinout, 24C00T-I/ST application, or 24C00T-I/ST equivalent, this page provides verified electrical parameters, package-specific terminal mapping, I²C timing compliance (100/400 kHz), endurance (1 million cycles), and real-world use context for embedded calibration and configuration storage.

Technical Context

The 24C00T-I/ST implements a fixed 128-bit memory array with no internal address pointer auto-increment on write; byte writes require explicit 4-bit word address input. Its I²C slave interface uses open-drain SDA/SCL with integrated Schmitt triggers and spike filtering (50 ns), enabling robust operation on noisy buses without external RC networks.

Write operations are self-timed with 3 ms typical page write time and automatic V_CC threshold detection (3.8 V nominal) that disables erase/write logic if supply drops below specification - preventing partial writes and data corruption during brown-out conditions.

Key Specifications

Pinout & Package

24C00T-I/ST is supplied in 5-lead SOT-23 package (JEDEC TO-236AB), with pin 1 = SCL, pin 2 = V_SS, pin 3 = SDA, pin 4 = NC, pin 5 = V_CC. The NC pin is internally unconnected and must be left floating or tied to ground per layout best practice.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 24C00T-I/ST, the 24AA00T-I/OT supports broader voltage flexibility but sacrifices 5 V-specific reliability features, while the AT24C01C-SSHM-T offers scalable density in the same footprint but omits brown-out write protection - making 24C00T-I/ST optimal for cost-sensitive, fixed-5V industrial calibration storage.

Availability

24C00T-I/ST is available at Aetrix Electronics and suitable for industrial sensor calibration, medical device ID storage, automotive ECU configuration, and consumer appliance settings requiring stable component supply across extended temperature ranges and long product lifecycles.

Supply support for 24C00T-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, headquartered in Chandler, Arizona, with global design and manufacturing operations.

The 24C00T-I/ST belongs to Microchip's legacy 24XX00 serial EEPROM family, engineered specifically for ultra-low-power, space-constrained nonvolatile storage of immutable configuration data in industrial and automotive environments.

FAQ

What is the maximum clock frequency supported by the 24C00T-I/ST?

The 24C00T-I/ST supports I²C clock frequencies up to 400 kHz when operated within its specified 4.5–5.5 V supply range. At 5.5 V, AC timing parameters such as T_HIGH (600 ns min) and T_LOW (1300 ns min) ensure reliable communication. Operation above 400 kHz is not guaranteed and violates the device's AC specifications - the 24C00T-I/ST does not support fast-mode plus (1 MHz) or high-speed mode.

Can the 24C00T-I/ST be used with a 3.3 V microcontroller I²C interface?

No, the 24C00T-I/ST requires a minimum V_CC of 4.5 V and is not 3.3 V tolerant. Its input thresholds (V_IL ≤ 0.3 V_CC, V_IH ≥ 0.7 V_CC) translate to ~1.35 V and ~3.15 V at 4.5 V, making direct connection to 3.3 V I²C buses unsafe without level translation. Using the 24C00T-I/ST with a 3.3 V MCU risks undervoltage operation, failed ACKs, and unreliable communication - select 24AA00T-I/OT instead for true 1.8–3.3 V compatibility.

Does the 24C00T-I/ST have built-in write protection?

The 24C00T-I/ST has no software-controlled write protection bits or hardware write-protect pin. Write enable is implicit upon receiving a valid I²C start condition with R/W = 0 and correct slave address (1010xxx0). Protection must be implemented externally via system-level access control or by omitting pull-up resistors on SDA/SCL during critical periods. The device does include V_CC threshold detection (3.8 V) that automatically inhibits writes during brown-out, serving as hardware-level corruption prevention - but this is not user-configurable write protection.

What is the purpose of the NC pin on the 24C00T-I/ST SOT-23 package?

The NC (No Connect) pin on the 24C00T-I/ST SOT-23 package (Pin 4) is internally unconnected and serves no electrical function. It may be left floating in the PCB layout, though grounding it improves mechanical stability and thermal dissipation marginally. Unlike some variants, this pin is not repurposed for write protect or address selection - referencing the official Microchip DS20001178J datasheet confirms Pin 4 is designated "NC" across all 5-lead SOT-23 versions of the 24C00T-I/ST.

How does ACK polling work with the 24C00T-I/ST during a write cycle?

ACK polling with the 24C00T-I/ST exploits the fact that the device stops acknowledging I²C addresses while performing its internal 3 ms write cycle. After issuing a STOP condition to initiate writing, the master immediately sends a repeated START followed by the 24C00T-I/ST's slave address with R/W = 0. If the 24C00T-I/ST is still busy, it does not pull SDA low (no ACK). The master retries until an ACK is received - confirming write completion. This method avoids fixed delays and maximizes bus efficiency, as documented in Section 7.0 of the DS20001178J datasheet.