Microchip Technology 34LC02-E/P

Overview

34LC02-E/P from Microchip Technology Inc. is a 2 Kbit I²C-compatible serial EEPROM with hardware and dual software write-protection, 1 MHz clock support (2.5–5.5 V), 16-byte page buffer, and operation down to 1.7 V. It features Schmitt-trigger inputs, slope-controlled outputs, and >1 million erase/write cycles - deployed in automotive body control modules for storing calibration data and configuration parameters.

For engineers reviewing the 34LC02-E/P datasheet, 34LC02-E/P pinout, 34LC02-E/P application, or 34LC02-E/P equivalent, key selection criteria include write-protect flexibility (permanent/resettable software + hardware WP), extended temperature range (−40°C to +125°C), PDIP-8 package compatibility, and I²C timing compliance at 1 MHz under 2.5–5.5 V.

Technical Context

The 34LC02-E/P implements a 256 × 8-bit memory array organized as a single block, accessed via a bidirectional 2-wire I²C bus where it operates exclusively as a slave device. Its internal address pointer auto-increments during sequential reads, and its write cycle is self-timed with typical duration of 5 ms.

Write protection is implemented through three independent mechanisms: hardware (WP pin tied to VCC), resettable software (SWP/CSWP commands), and permanent software (PSWP command). All three operate independently and can be combined - e.g., hardware WP enables full-array lock while SWP protects only addresses 00h–7Fh.

Key Specifications

Pinout & Package

34LC02-E/P is supplied in an 8-lead plastic dual in-line package (PDIP) with 0.300-inch body width, RoHS-compliant matte tin plating, and standard through-hole mounting footprint.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AT24C02C-SSHM-T and M95020-RMN6TP, the 34LC02-E/P uniquely combines automotive-grade temperature range, triple-layer write protection (hardware + resettable + permanent), and I²C-1MHz timing - making it the only option qualified for safety-critical automotive configuration storage where irreversible key locking and noise immunity are mandatory.

Availability

34LC02-E/P is available at Aetrix Electronics and suitable for automotive body control, industrial PLC configuration, medical infusion pump calibration, and smart energy meter firmware patch storage requiring stable component supply across extended temperature and long lifecycle commitments.

Supply support for 34LC02-E/P 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 Inc. is a U.S.-based semiconductor company specializing in microcontrollers, analog devices, and memory solutions for embedded control applications.

The 34LC02-E/P belongs to Microchip's serial EEPROM product line, engineered specifically for automotive and industrial systems demanding high reliability, extended temperature operation, and robust write-protection architecture.

FAQ

What is the maximum I²C clock frequency supported by the 34LC02-E/P?

The 34LC02-E/P supports up to 1 MHz I²C clock frequency when V_CC is 2.5 V or higher. At lower voltages (2.2–2.49 V), the maximum clock drops to 400 kHz per DS22029F-page 4, Table 1-2. This dual-speed capability allows the 34LC02-E/P to maintain high throughput in 3.3 V and 5 V systems while remaining compatible with legacy 400 kHz controllers during brown-out conditions.

Does the 34LC02-E/P have permanent write protection, and how is it enabled?

Yes, the 34LC02-E/P supports Permanent Software Write-Protect (PSWP), which irreversibly locks addresses 00h–7Fh. It is enabled by sending the PSWP command (device type identifier '0110', matching A2/A1/A0 levels) with appropriate voltage and timing per DS22029F-page 13, Table 7-1. Once executed, PSWP cannot be cleared by power cycling, firmware, or WP pin state - ensuring cryptographic keys stored in the lower half remain tamper-proof for the device lifetime.

What package type is used for the 34LC02-E/P, and what does the 'E/P' suffix indicate?

The 34LC02-E/P uses an 8-lead plastic dual in-line package (PDIP) with 0.300-inch body width. The 'E' denotes Automotive temperature grade (−40°C to +125°C), and 'P' specifies the PDIP package - confirmed by Microchip's packaging table (DS22029F-page 15) and marking example "34LC02I SN 0810 3EC" where 'P' is implied by the PDIP-specific marking format and mechanical drawing references.

How does hardware write protection interact with software write protection on the 34LC02-E/P?

Hardware write protection (via WP pin) and software write protection (SWP/PSWP) operate independently on the 34LC02-E/P. When WP = VCC, the entire array (00h–FFh) is locked regardless of SWP/PSWP state. However, SWP/PSWP continue to govern access to the lower 128 bytes even when WP is disabled (WP = VSS). This layered approach allows system designers to enforce full-array lock during manufacturing (WP high) while retaining field-upgrade capability for unprotected regions using SWP commands - a capability verified in DS22029F-page 12, Section 7.0.

Can multiple 34LC02-E/P devices share the same I²C bus, and how many are supported?

Yes, up to eight 34LC02-E/P devices can be cascaded on a single I²C bus using the A2, A1, and A0 address pins to generate unique 3-bit chip select codes. Each device responds only when its A2–A0 logic levels match the corresponding bits in the master's control byte (DS22029F-page 7, Figure 3-2). This addressing scheme is fully supported in the PDIP package; note that the SOT-23 variant omits A2 and limits count to four devices, but the 34LC02-E/P (PDIP) retains all three pins and full eight-device capability.