Microchip Technology AT24C32C-TH-B

Overview

AT24C32C-TH-B from Microchip Technology (formerly Atmel) is a 32 Kbit I²C-compatible serial EEPROM organized as 4096 × 8 bits, operating across 1.8 V to 5.5 V supply range, featuring hardware write protection via WP pin, 32-byte page write capability, and 1 MHz max clock frequency at 5.0 V. It is widely deployed in industrial sensor calibration storage, embedded system configuration retention, and power-meter firmware parameter backup.

For engineers reviewing the AT24C32C-TH-B datasheet, AT24C32C-TH-B pinout, AT24C32C-TH-B application, or AT24C32C-TH-B equivalent, key selection considerations include its 1.8–5.5 V wide-voltage operation, 8-lead TSSOP package with NiPdAu lead finish, 1 million write endurance, 100-year data retention, and compatibility with standard 2-wire bus topologies supporting up to eight cascaded devices.

Technical Context

The AT24C32C-TH-B implements a synchronous 2-wire serial interface with Schmitt-triggered, noise-filtered SCL/SDA inputs and open-drain SDA output. Its internal address counter supports current-address, random-address, and sequential read modes, while the A0–A2 pins enable hardware device addressing for multi-drop bus configurations.

Write operations are managed through byte-write and 32-byte page-write protocols, both followed by self-timed internal write cycles (≤5 ms). The WP pin provides hardware-level memory lockout when driven high, and acknowledge polling enables host-driven readiness detection without fixed delay timing.

Key Specifications

Pinout & Package

AT24C32C-TH-B is packaged in an 8-lead Thin Shrink Small Outline Package (TSSOP), 4.4 mm body width, lead-free/halogen-free, with NiPdAu lead finish. Dimensions: 3.00 mm × 4.40 mm × 1.20 mm max height.

Key Features

Applications

Equivalent & Alternatives

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

Compared with M24C32-WMN6TP and CAT24C32HU4I-GT3, the AT24C32C-TH-B delivers highest I²C throughput (1 MHz at 5 V), consistent 8-lead TSSOP packaging with NiPdAu finish for solderability, and proven field reliability in metering and sensor applications - making it optimal for performance-critical, volume-manufactured designs.

Availability

AT24C32C-TH-B is available at Aetrix Electronics and suitable for industrial sensor calibration, smart energy metering, and embedded system configuration requiring stable component supply, long-term lifecycle support, and RoHS-compliant manufacturing.

Supply support for AT24C32C-TH-B 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 global semiconductor company specializing in microcontrollers, analog devices, and memory solutions, with broad industrial and automotive qualification portfolios.

The AT24C32C-TH-B belongs to Microchip's serial EEPROM product line, engineered for robust, low-power, and long-life nonvolatile data storage in resource-constrained embedded systems across industrial, medical, and energy sectors.

FAQ

What is the maximum I²C clock frequency supported by the AT24C32C-TH-B?

The AT24C32C-TH-B supports up to 1 MHz I²C clock frequency when operated at VCC = 5.0 V. At the minimum supply voltage of 1.8 V, the maximum guaranteed clock frequency is 400 kHz. These values are specified in the AC Characteristics table of the official datasheet (Rev. 5298A), and timing compliance must be verified against tLOW, tHIGH, and rise/fall time constraints for the target VCC.

Does the AT24C32C-TH-B require external pull-up resistors on SDA and SCL lines?

Yes, the AT24C32C-TH-B requires external pull-up resistors on both SDA and SCL lines because its SDA pin is open-drain and SCL is a CMOS input. Recommended values range from 1 kΩ to 10 kΩ depending on bus capacitance and desired rise time; 4.7 kΩ is typical for standard-mode (100 kHz) and fast-mode (400 kHz) buses. The AT24C32C-TH-B datasheet specifies RL = 1.3 kΩ for 2.5 V/5.0 V and 10 kΩ for 1.8 V operation.

How does the WP (Write Protect) pin function on the AT24C32C-TH-B?

The WP pin on the AT24C32C-TH-B is an active-high hardware write protection input. When WP is driven to VCC, all write operations-including byte writes, page writes, and write-enable commands-are inhibited. When WP is grounded or left floating (internally pulled down if capacitive coupling to VCC <3 pF), normal write functionality is enabled. This provides fail-safe memory locking independent of firmware state.

Can multiple AT24C32C-TH-B devices share the same I²C bus?

Yes, up to eight AT24C32C-TH-B devices can share a single I²C bus using hardware address lines A0, A1, and A2. Each device's 3-bit address is set by connecting these pins to VCC or GND (or leaving them floating, which defaults to logic low). The resulting 7-bit device address ranges from 0x50 to 0x57, allowing unambiguous addressing without software arbitration.

What is the write cycle time for the AT24C32C-TH-B, and how should hosts handle it?

The AT24C32C-TH-B has a maximum internal write cycle time (tWR) of 5 ms, applicable to both byte and page writes. During this period, the device does not respond to I²C requests. Hosts must either wait the full 5 ms or use acknowledge polling-repeatedly sending START + device address-to detect completion. Polling is preferred for deterministic timing and reduced latency in responsive systems.