Microchip Technology AT24C32E-PUM

Overview

AT24C32E-PUM from Microchip Technology is a 32-Kbit I²C-compatible serial EEPROM organized as 4,096 × 8 bits, operating from 1.7V to 3.6V with industrial temperature range (−40°C to +85°C), 1 MHz Fast Mode Plus support at ≥2.5V, and hardware write-protection via dedicated WP pin - used for nonvolatile configuration storage in embedded microcontroller systems.

For engineers reviewing the AT24C32E-PUM datasheet, AT24C32E-PUM pinout, AT24C32E-PUM application, or AT24C32E-PUM equivalent, key selection criteria include I²C bus voltage compatibility (1.7–3.6V), page-write timing (≤5 ms), ultra-low standby current (0.8 µA max), hardware write-protect implementation, and package-specific pin mapping for SOIC-8/TSSOP-8/UDFN-8 variants.

Technical Context

The AT24C32E-PUM implements a two-wire I²C interface with Schmitt-triggered, filtered SCL/SDA inputs for noise immunity, supports Standard (100 kHz), Fast (400 kHz), and Fast Mode Plus (1 MHz) clock rates depending on VCC level, and uses an internal high-voltage generation circuit for EEPROM cell programming without external charge pumps.

It features a cascaded addressing architecture with three hardware address pins (A0–A2) enabling up to eight devices on one bus, a dedicated open-drain WP pin for full-array hardware write protection, and automatic power-on reset (POR) with 100 µs tPUP delay before command acceptance.

Key Specifications

Pinout & Package

AT24C32E-PUM is supplied in 8-lead PDIP, SOIC, and TSSOP packages - all sharing identical 8-pin dual-in-line pinout with GND at Pin 4, VCC at Pin 8, SDA at Pin 5, SCL at Pin 6, WP at Pin 7, and address pins A0–A2 at Pins 1–3 respectively.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AT24C32E-PUM, AT24C32D-SSHM-T offers higher temperature resilience at the cost of broader qualification testing overhead, while M24C32-WMN6TP trades hardware write-protection for lower unit cost and alternate qualification - both require validation of WP functionality and thermal derating in final design.

Availability

AT24C32E-PUM is available at Aetrix Electronics and suitable for industrial sensor calibration, medical device configuration, smart energy metering, automotive body control modules, and portable instrumentation requiring stable component supply across long production lifecycles.

Supply support for AT24C32E-PUM 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 U.S.-based semiconductor company specializing in microcontrollers, analog devices, and memory products, with ISO 9001-certified manufacturing and global distribution.

The AT24C32E-PUM belongs to Microchip's AT24Cxx family of I²C serial EEPROMs designed for reliable, low-voltage nonvolatile data storage in space-constrained embedded systems.

FAQ

What is the maximum I²C clock frequency supported by the AT24C32E-PUM?

The AT24C32E-PUM supports 100 kHz Standard Mode (1.7–3.6V), 400 kHz Fast Mode (1.7–3.6V), and 1 MHz Fast Mode Plus (2.5–3.6V). The actual achievable frequency depends on VCC level and bus capacitance - at 3.3V, full 1 MHz operation is guaranteed per DS20006109B AC specifications. Host firmware must configure clock rate accordingly to avoid timing violations.

Does the AT24C32E-PUM require external pull-up resistors on SDA and SCL lines?

Yes, the AT24C32E-PUM requires external pull-up resistors on both SDA and SCL lines because SDA is open-drain and SCL is an input. Microchip specifies maximum pull-up values of 10 kΩ for 100 kHz, 4 kΩ for 400 kHz, and 1.3 kΩ for 1 MHz operation - values must be selected based on bus capacitance and desired rise time per Figure 4-1 timing diagram in the AT24C32E-PUM datasheet.

How does the Write-Protect (WP) pin function on the AT24C32E-PUM?

The WP pin on the AT24C32E-PUM is an active-high hardware lock: when driven to VCC, it inhibits all write operations to the entire memory array; when grounded, normal writes are enabled. If left floating, it is internally pulled down to GND, but Microchip recommends hard-wiring WP to a known state to prevent noise-induced false writes - a design requirement explicitly stated in Section 2.5 of the AT24C32E-PUM datasheet.

What is the write endurance and data retention specification for the AT24C32E-PUM?

The AT24C32E-PUM guarantees 1,000,000 write cycles per memory location and 100 years of data retention at 55°C, as validated through qualification testing per Table 4-6 in the official datasheet. These figures apply across the full industrial temperature range (−40°C to +85°C) and 1.7–3.6V supply range, making it suitable for applications requiring decades-long archival storage without refresh.

Can multiple AT24C32E-PUM devices share the same I²C bus?

Yes, up to eight AT24C32E-PUM devices can operate concurrently on a single I²C bus using hardware address pins A0, A1, and A2 to generate unique 7-bit slave addresses (1010xxx). Each pin must be hard-wired to VCC or GND - floating is discouraged due to capacitive coupling risks. This cascading capability is confirmed in Section 3.1 and Table 6-1 of the AT24C32E-PUM datasheet.