Microchip Technology AT24C08C-MAPD-T

Overview

AT24C08C-MAPD-T from Microchip Technology (formerly Atmel) is an automotive-grade 8-Kbit I²C serial EEPROM organized as 1,024 words × 8 bits, housed in an 8-pad UDFN (2.0 mm × 3.0 mm, 0.5 mm pitch) package. It operates from 2.5 V to 5.5 V (Grade 1), supports 400 kHz I²C communication, features hardware write protection via the WP pin, and delivers 1,000,000 write cycles with 100-year data retention - deployed in engine control units, ADAS sensor modules, and infotainment configuration storage.

For engineers reviewing the AT24C08C-MAPD-T datasheet, AT24C08C-MAPD-T pinout, AT24C08C-MAPD-T application, or AT24C08C-MAPD-T equivalent, key selection criteria include Grade 1 automotive temperature range (−40°C to +125°C), 16-byte page write capability, Schmitt-triggered noise-immune inputs, self-timed 5 ms max write cycle, and compatibility with standard 2-wire I²C host controllers in space-constrained automotive PCBs.

Technical Context

The AT24C08C-MAPD-T implements a dedicated 2-wire I²C interface with open-drain SDA/SCL pins, internal address decoding using only the A2 pin (A0/A1 are no-connect), and a hardwired device address prefix of '1010' followed by A2 and two page-address bits (P1, P0). Its memory is partitioned into 64 pages of 16 bytes each, enabling efficient partial-page writes without rollover within the same page boundary.

It integrates on-chip high-voltage generation for EEPROM programming, Schmitt-trigger inputs with noise filtering (t_I = 50 ns), and automatic acknowledge polling support during write cycles. The device enters low-power standby mode after Stop conditions or power-up, drawing ≤4.0 μA at 5.0 V, and features built-in power-on reset (POR) with monotonic V_CC ramp requirements (≤1 ms rise time).

Key Specifications

Pinout & Package

AT24C08C-MAPD-T uses an 8-pad UDFN package (2.0 mm × 3.0 mm body, 0.5 mm pitch, JEDEC MO-229 variation), optimized for high-density automotive PCB layouts with exposed thermal pad (pin 5) for improved heat dissipation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with M24C08-RMN6TP and CAT24C08HU4I-GT3, AT24C08C-MAPD-T offers guaranteed 400 kHz operation down to 2.5 V and explicit A2-only addressing documentation, making it preferable for low-voltage robustness and multi-device I²C bus design in compact automotive modules.

Availability

AT24C08C-MAPD-T is available at Aetrix Electronics and suitable for engine control units, ADAS sensor modules, and infotainment systems requiring stable component supply across extended automotive product lifecycles.

Supply support for AT24C08C-MAPD-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 acquired Atmel in 2016 and maintains its automotive EEPROM portfolio with AEC-Q100 qualified processes, rigorous lot traceability, and long-term product availability commitments.

The AT24CxxC family was designed specifically for automotive subsystems needing reliable, low-power, I²C-accessible nonvolatile memory - emphasizing noise immunity, wide voltage operation, and extended temperature resilience in harsh ECU environments.

FAQ

What is the maximum I²C clock frequency supported by AT24C08C-MAPD-T at 2.5 V?

The AT24C08C-MAPD-T supports a maximum I²C clock frequency of 400 kHz at V_CC = 2.5 V, as specified in the AC Characteristics table (Table 5-3) of the official datasheet. This ensures interoperability with standard microcontroller I²C peripherals operating at standard mode speeds, even at the lower end of its Grade 1 voltage range. The device maintains full timing compliance including t_LOW ≥ 1200 ns and t_HIGH ≥ 600 ns under these conditions.

How many AT24C08C-MAPD-T devices can share the same I²C bus?

Up to two AT24C08C-MAPD-T devices can be addressed on a single I²C bus. This is because the AT24C08C uses only the A2 pin for hardware device addressing (A0 and A1 are no-connect), providing one binary bit (A2 = 0 or 1) to differentiate devices. The base I²C address prefix is '1010', followed by A2 and two page address bits (P1, P0), resulting in two unique 7-bit device addresses: 0x50 (A2 = 0) and 0x51 (A2 = 1).

Does AT24C08C-MAPD-T require external pull-up resistors on SDA and SCL lines?

Yes, AT24C08C-MAPD-T requires external pull-up resistors on both SDA and SCL lines because it uses open-drain outputs. The datasheet specifies typical values of 2.2 kΩ for 3.3 V systems and 4.7 kΩ for 5 V systems, connected to the same V_CC rail. These resistors ensure proper logic high levels and meet rise time requirements (t_R ≤ 300 ns) under specified bus capacitance (≤100 pF).

What is the purpose of the exposed pad (EP) on the AT24C08C-MAPD-T UDFN package?

The exposed pad (EP) on the AT24C08C-MAPD-T is internally connected to GND and serves dual purposes: thermal dissipation and EMI suppression. It must be soldered to a PCB copper pour tied to the system ground plane. This improves thermal resistance (reducing junction temperature rise during write cycles) and lowers high-frequency impedance, enhancing immunity to automotive electromagnetic noise - a requirement explicitly validated under AEC-Q100 stress testing.

Can AT24C08C-MAPD-T perform partial page writes, and what happens if more than 16 bytes are sent in one page write sequence?

Yes, AT24C08C-MAPD-T supports partial page writes - any number of bytes from 1 to 16 may be written in a single page write transaction. If more than 16 bytes are transmitted, the internal word address rolls over to the beginning of the same page (not the next page), overwriting previously written data in that page. This behavior is intentional and documented in Section 8 (Write Operations); designers must manage address boundaries in firmware to avoid unintended data corruption.