Microchip Technology AT29C512-20PI

Overview

AT29C512-20PI from Microchip Technology is a 512 Kbit (64K × 8) parallel-access EEPROM with 200 ns maximum access time, single 5V supply operation, and hardware write protection via WP pin. It supports byte-write and page-write (up to 64 bytes) modes and is used in industrial control systems for nonvolatile parameter storage.

For engineers reviewing the AT29C512-20PI datasheet, AT29C512-20PI pinout, AT29C512-20PI application, or AT29C512-20PI equivalent, key selection considerations include write endurance (10,000 cycles), data retention (100 years), 5V-only operation, and compatibility with standard microprocessor bus interfaces.

Technical Context

This device implements a CMOS-based floating-gate EEPROM array with on-chip address latches and data latches. It uses a two-phase write algorithm requiring V_PP = +12V only during programming - not during read or standby - and features automatic write timing controlled by an internal timer.

Hardware write protection is enforced when WP is driven low, disabling all write operations including byte and page writes. The device enters low-power standby mode when CE is high, drawing ≤100 µA typical current.

Key Specifications

Pinout & Package

AT29C512-20PI is housed in a 28-pin plastic DIP (Dual In-line Package) with 0.6-inch body width and through-hole mounting. Pin spacing conforms to JEDEC MS-011AC standard.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AT29C512-20PI, AT28C64B-15PU offers faster access but lower density and higher programming voltage, while MX29LV512CTTI-12G eliminates V_PP but introduces erase-before-write overhead unsuitable for dynamic parameter logging.

Availability

AT29C512-20PI is available at Aetrix Electronics and suitable for industrial control systems, medical instrumentation, automotive body electronics, and test equipment requiring stable component supply and long-term obsolescence management.

Supply support for AT29C512-20PI 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 nonvolatile memory solutions for embedded applications.

The AT29C512-20PI belongs to Microchip's parallel EEPROM product line, designed specifically for legacy 5V microprocessor systems requiring reliable, pin-compatible, long-life nonvolatile storage without complex programming infrastructure.

FAQ

What is the programming voltage requirement for AT29C512-20PI?

The AT29C512-20PI requires +12V applied to the V_PP pin only during write operations. This voltage is not needed for read or standby modes. The device incorporates internal timing to automatically terminate the write cycle after approximately 10 ms, eliminating external pulse generation. Proper decoupling between V_PP and ground is essential to avoid write failures. AT29C512-20PI must never be operated with V_PP left floating or shorted to V_CC.

Does AT29C512-20PI support page-write mode, and what is the page size?

Yes, AT29C512-20PI supports page-write mode with a fixed page size of 64 bytes. This allows up to 64 consecutive bytes to be written in a single write cycle, significantly reducing total programming time compared to byte-write mode. Page-write requires proper address alignment (A5–A0 = 0) and remains enabled until the next WE transition. AT29C512-20PI does not support variable or configurable page sizes.

How does hardware write protection work on AT29C512-20PI?

Hardware write protection on AT29C512-20PI is controlled by the WP (Write Protect) pin. When WP is driven low, all write operations - including byte-write, page-write, and clear operations - are disabled regardless of CE, OE, or WE states. This protection remains active during power-up and power-down transitions. AT29C512-20PI does not implement software-controlled write protection; WP is the sole deterministic mechanism for preventing unintended writes.

What is the maximum clock frequency supported by AT29C512-20PI when interfaced with a microprocessor?

AT29C512-20PI does not use a clock signal; it operates asynchronously using CE, OE, and WE control lines. Its 200 ns access time supports direct interfacing with microprocessors running at up to 5 MHz bus frequency, assuming standard 8051 or Z80 timing budgets. Timing margins must account for PCB trace delays and driver rise/fall times. AT29C512-20PI has no internal oscillator or clock input pin.

Is AT29C512-20PI RoHS compliant and lead-free?

AT29C512-20PI is manufactured in a RoHS-compliant process and meets EU Directive 2011/65/EU requirements. The 28-pin PDIP package uses lead-free finish on leads, though the internal die attach and bond wires may contain lead per exemption 7a. Full compliance documentation, including material declarations and test reports, is available from Microchip upon request. AT29C512-20PI is not subject to REACH SVHC candidate list restrictions.