Microchip Technology AT24C32D-MAHM-T

Overview

AT24C32D-MAHM-T from Microchip Technology is a 32-Kbit I²C-compatible serial EEPROM organized as 4,096 × 8 bits, operating from 1.7V to 5.5V across -40°C to +85°C, with hardware write protection (WP), 32-byte page write capability, and FM+ support up to 1 MHz at ≥2.5V - deployed in industrial sensor calibration, embedded configuration storage, and power-management parameter retention.

For engineers reviewing the AT24C32D-MAHM-T datasheet, AT24C32D-MAHM-T pinout, AT24C32D-MAHM-T application, or AT24C32D-MAHM-T equivalent, key selection criteria include VCC range compatibility, I²C bus speed mode support (Standard/Fast/FM+), WP pin functionality, page write timing (≤5 ms), and package-specific pin mapping for 8-pad UDFN.

Technical Context

The AT24C32D-MAHM-T implements a true I²C slave interface with open-drain SDA/SCL, Schmitt-triggered inputs, and integrated noise filtering. It supports three I²C speed modes: 100 kHz (1.7–5.5V), 400 kHz (1.7–5.5V), and 1 MHz Fast Mode Plus (2.5–5.5V), with strict AC timing compliance including tLOW/tHIGH, tSU.STA, and tHD.DAT.

Internally organized as 128 pages × 32 bytes, it uses A0–A2 address pins for multi-device bus addressing (up to eight devices), with internal pull-downs enabling default 0x50 device address when pins float. Write protection is implemented via dedicated WP pin tied to VCC/GND, not software-configurable.

Key Specifications

Pinout & Package

AT24C32D-MAHM-T is supplied in an 8-pad UDFN (2.0 mm × 1.6 mm, 0.5 mm pitch) package with wettable flank leads for automated optical inspection. The exposed pad is internally connected to GND and must be soldered to PCB ground plane for thermal and EMI performance.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AT24C32AN-SSHM-T, the AT24C32D-MAHM-T offers superior board-area efficiency and automated assembly compatibility; versus M24C32-WMN6TP, it delivers guaranteed FM+ performance and full industrial temperature qualification - making it the optimal choice for compact, high-reliability embedded systems.

Availability

AT24C32D-MAHM-T is available at Aetrix Electronics and suitable for industrial sensor calibration, embedded configuration storage, and power-management parameter retention requiring stable component supply across extended temperature ranges and long product lifecycles.

Supply support for AT24C32D-MAHM-T 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 leading provider of microcontroller, analog, FPGA, and memory solutions, with core expertise in low-power, high-reliability semiconductor design for industrial, automotive, and communications markets.

The AT24C32D product line delivers I²C serial EEPROMs optimized for robustness in harsh environments, emphasizing low-voltage operation, extended temperature tolerance, and hardware-based data protection - targeting mission-critical configuration and calibration storage.

FAQ

What is the maximum I²C clock frequency supported by the AT24C32D-MAHM-T?

The AT24C32D-MAHM-T supports 100 kHz (Standard Mode), 400 kHz (Fast Mode), and 1 MHz (Fast Mode Plus) I²C clock frequencies. FM+ operation requires VCC ≥2.5V; below that, maximum speed is 400 kHz. All modes maintain full AC timing compliance per DS20006047A, with tLOW/tHIGH and setup/hold times validated across voltage and temperature ranges. This makes AT24C32D-MAHM-T suitable for both legacy and high-speed I²C systems.

Does the AT24C32D-MAHM-T require external pull-up resistors on SDA and SCL lines?

Yes, the AT24C32D-MAHM-T requires external pull-up resistors on both SDA and SCL lines because they are open-drain outputs. Microchip specifies maximum values of 10 kΩ for 100 kHz, 4 kΩ for 400 kHz, and 1.3 kΩ for 1 MHz operation, based on bus capacitance (CL = 100 pF). Failure to install appropriate pull-ups will result in communication failure or intermittent ACK/NACK errors. This requirement applies identically across all AT24C32D-MAHM-T implementations.

How does the Write-Protect (WP) pin function on the AT24C32D-MAHM-T?

The WP pin on the AT24C32D-MAHM-T is an active-high hardware enable that disables all write operations (byte, page, and erase) when driven to VCC. When tied to GND, full write access is granted. If left floating, the internal strong pull-down defaults WP to GND - but Microchip recommends explicit connection to avoid noise-induced glitches. This hardware-level protection operates independently of I²C commands and remains effective during power transitions, making AT24C32D-MAHM-T ideal for safety-critical data retention.

What is the memory organization of the AT24C32D-MAHM-T, and how does it affect addressing?

The AT24C32D-MAHM-T organizes its 32-Kbit memory as 128 pages × 32 bytes, requiring two 8-bit word address bytes (A11–A0) after the device address. The first byte contains A11–A8 in bits 3–0 (bits 7–4 are "don't care"), and the second byte contains A7–A0. This structure enables seamless 16-bit addressing within the 4,096-word space. Because AT24C32D-MAHM-T uses the same addressing scheme as other AT24Cxx devices, firmware can reuse existing I²C EEPROM drivers with minimal modification.

Is the AT24C32D-MAHM-T compatible with standard I²C protocol stacks and controllers?

Yes, the AT24C32D-MAHM-T is fully compliant with the NXP I²C-bus specification (UM10204), supporting Start/Stop conditions, 7-bit slave addressing, ACK/NACK handshaking, and repeated Start. It implements standard I²C timing parameters (tSU.STA, tHD.STA, tLOW, etc.) across all supported speeds and voltage ranges. No special controller extensions or custom firmware are needed - AT24C32D-MAHM-T integrates transparently into any I²C master environment, including ARM Cortex-M, PIC, ESP32, and Linux I²C subsystems.