Microchip Technology AT24C512B-PU

Overview

AT24C512B-PU from Microchip Technology (formerly Atmel) is a 512 Kbit (65,536 × 8) two-wire serial EEPROM with 1.8 V to 3.6 V operation, 128-byte page write capability, and hardware write protection via the WP pin. It supports up to 1 MHz I²C communication at 2.5–5.5 V and 400 kHz at 1.8 V, and is housed in an 8-lead PDIP package for through-hole industrial control and embedded data logging applications.

For engineers reviewing the AT24C512B-PU datasheet, AT24C512B-PU pinout, AT24C512B-PU application, or AT24C512B-PU equivalent, this page delivers verified electrical specs, validated pin functions, real-world use cases in power-sensitive systems, and confirmed alternative parts with documented functional and packaging differences.

Technical Context

The AT24C512B-PU implements a standard two-wire (I²C-compatible) interface with Schmitt-triggered, noise-filtered SDA and SCL inputs. Its internal architecture features a 16-bit address counter, cascading support for up to eight devices on one bus via A0–A2 address pins, and a dedicated write-protect circuit that disables all writes when WP = V_CC.

It uses an internal high-voltage pump and timing logic for self-timed erase/write cycles, enabling guaranteed 5 ms max write time per page. Memory endurance is rated at 1,000,000 write cycles with 40-year data retention at 25°C - validated across industrial temperature range (–40°C to +85°C).

Key Specifications

Pinout & Package

AT24C512B-PU is supplied in an 8-lead PDIP (Plastic Dual In-line Package), 0.300" wide body, with standard through-hole mounting and JEDEC MS-001 BA footprint compatibility.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AT24C512BN-SH-T and M24C512-WMN6TP, the AT24C512B-PU uniquely combines PDIP packaging for hand-soldered development, guaranteed 1.8 V operation, and Atmel's proven 40-year retention spec - making it optimal for low-volume industrial prototypes and repair-ready designs.

Availability

AT24C512B-PU is available at Aetrix Electronics and suitable for industrial control, medical diagnostics, and smart metering applications requiring stable component supply, long-term obsolescence management, and RoHS-compliant through-hole solutions.

Supply support for AT24C512B-PU 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 full product support, documentation, and qualification for the AT24C512B series. The company specializes in secure, reliable microcontrollers and memory solutions for industrial and automotive markets.

The AT24C512B belongs to Microchip's serial EEPROM product line, engineered for robust data storage in harsh environments - emphasizing endurance, low-voltage operation, and I²C interoperability across diverse host platforms.

FAQ

What is the maximum I²C clock frequency supported by the AT24C512B-PU?

The AT24C512B-PU supports up to 1 MHz I²C clock frequency when operated at 2.5 V to 5.5 V, and 400 kHz at 1.8 V to 3.6 V. These values are specified in Table 2-3 of the official datasheet and reflect tested AC characteristics under industrial temperature conditions. The AT24C512B-PU does not support higher frequencies such as 3.4 MHz (fast-mode plus) without risk of timing violation or data corruption.

Does the AT24C512B-PU require external pull-up resistors on SDA and SCL lines?

Yes, the AT24C512B-PU requires external pull-up resistors on both SDA and SCL lines because its I/O pins are open-drain. Recommended values are 1.3 kΩ for 2.5 V/5 V operation and 10 kΩ for 1.8 V operation, as defined in Note 2 of Table 2-3. Omitting pull-ups will prevent proper I²C bus signaling and cause communication failure in the AT24C512B-PU.

How many devices can share the same I²C bus with the AT24C512B-PU?

Up to eight AT24C512B-PU devices can share a single I²C bus using the A0, A1, and A2 address pins. Each pin can be hardwired to V_CC or GND to generate a unique 3-bit device address, yielding eight distinct combinations (000 to 111). This cascading capability is explicitly confirmed in Section 4 ("Device Addressing") of the AT24C512B-PU datasheet.

What happens if the WP pin on the AT24C512B-PU is left unconnected?

If the WP pin on the AT24C512B-PU is left floating, it is internally pulled down to GND, enabling normal write operations. However, Atmel strongly recommends connecting WP to a known logic state (GND for write-enable or V_CC for write-protect) due to potential capacitive coupling in noisy environments. Leaving WP unconnected risks unintended writes or failures in the AT24C512B-PU during EMI exposure.

Is the AT24C512B-PU compatible with 5 V I²C systems?

No, the AT24C512B-PU is not 5 V tolerant. It operates only within 1.8 V to 3.6 V (low-voltage variant), as indicated by the "-PU" suffix and confirmed in the Ordering Information table. For 5 V systems, the AT24C512B-PU25 variant (2.5 V to 5.5 V) must be used - the AT24C512B-PU itself will not function reliably or safely above 3.6 V.