Microchip Technology 47L04-E/P

Overview

47L04-E/P from Microchip Technology is a 4 Kbit (512 × 8) I²C serial EERAM combining volatile SRAM with nonvolatile EEPROM backup, operating at 2.7–3.6 V and supporting up to 1 MHz I²C clock, with automatic power-loss store/recall via external capacitor and hardware store pin (HS), used in automotive and industrial data-logging systems requiring persistent memory without battery support.

For engineers reviewing the 47L04-E/P datasheet, 47L04-E/P pinout, 47L04-E/P application, or 47L04-E/P equivalent, this page delivers verified technical context, exact pin functions, real-world use cases in power-fail-safe systems, and two validated alternative parts with documented functional and application-level differences.

Technical Context

The 47L04-E/P implements a dual-memory architecture: 512 × 8-bit SRAM for high-speed read/write access and integrated EEPROM for nonvolatile retention (>200 years), with automatic Store triggered by VCC falling below 2.4–2.6 V (VTRIP) and automatic Recall on power-up. Its I²C interface supports standard, fast, and high-speed modes (100 kHz/400 kHz/1 MHz) with Schmitt-trigger inputs and zero-cycle-delay transfers.

Control logic includes a volatile AM (Array Modified) bit that tracks SRAM changes since last Store/Recall, nonvolatile BP<2:0> bits enabling software-selectable write protection (from 1/64 to full array), and ASE bit enabling/disabling Auto-Store. The HS pin provides hardware-initiated Store with 150 ns minimum pulse width and event flagging via STATUS register EVENT bit.

Key Specifications

Pinout & Package

47L04-E/P is supplied in 8-Lead PDIP (Plastic Dual In-line Package), a through-hole package suitable for prototyping, legacy industrial PCBs, and high-reliability environments where mechanical robustness and thermal cycling stability are critical.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 47L04-I/P, the 47L04-E/P adds extended temperature capability and AEC-Q100 qualification for harsh environments; compared with FM24V04, it trades F-RAM's infinite endurance for dedicated power-fail management features including VCAP-triggered Auto-Store, HS pin, and EVENT flag - making it optimal for automotive and industrial systems requiring forensic power-event tracking.

Availability

47L04-E/P is available at Aetrix Electronics and suitable for automotive telematics, industrial PLCs, smart metering, and medical device calibration storage requiring stable component supply across extended temperature and long product lifecycles.

Supply support for 47L04-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 leading provider of microcontrollers, analog components, and memory solutions, headquartered in Chandler, Arizona, with global design and manufacturing operations.

The 47L04-E/P belongs to Microchip's EERAM product line, designed specifically for applications needing seamless, low-overhead integration of volatile speed and nonvolatile reliability - targeting automotive, industrial, and medical systems where power interruption resilience is mission-critical.

FAQ

What is the primary function of the VCAP pin on the 47L04-E/P?

The VCAP pin on the 47L04-E/P connects to an external 5–6.8 µF capacitor that supplies hold-up energy during VCC collapse, enabling automatic SRAM-to-EEPROM Store when VCC falls below the 2.4–2.6 V trip threshold. Without VCAP, Auto-Store must be disabled (ASE = 0) and manual Store initiated via HS pin or software command to prevent EEPROM corruption.

How does the 47L04-E/P differ from standard I²C EEPROMs like the 24LC04?

Unlike standard I²C EEPROMs such as the 24LC04, the 47L04-E/P integrates a 512 × 8-bit SRAM array with instantaneous read/write access and automatic background EEPROM backup. It eliminates write-cycle delays (no 5–10 ms wait per byte), supports 1 MHz I²C, and provides hardware Store triggering and nonvolatile event detection - making it suitable for real-time data capture where EEPROM latency is unacceptable.

Can the 47L04-E/P operate without an external capacitor on the VCAP pin?

Yes, the 47L04-E/P can operate without an external capacitor on VCAP if Auto-Store is disabled (ASE = 0) and VCAP is tied directly to VCC. In this mode, Store operations must be initiated manually via the HS pin or software command. Omitting VCAP while enabling Auto-Store risks EEPROM data corruption during uncontrolled power loss.

What does the AM (Array Modified) bit indicate in the 47L04-E/P STATUS register?

The AM bit in the 47L04-E/P STATUS register is a volatile flag indicating whether the SRAM array has been written since the last Store or Recall operation: AM = 1 means SRAM contents differ from EEPROM, enabling Auto-Store and Hardware Store; AM = 0 means arrays match and Store operations are inhibited unless forced via software command. AM is cleared automatically after each successful Store or Recall.

Is the 47L04-E/P pin-compatible with other devices in the 47XXX family?

Yes, the 47L04-E/P shares identical 8-pin PDIP pinout and I²C interface compatibility with all 47XXX variants (47C04, 47L16, 47C16), differing only in density (4 Kbit vs. 16 Kbit) and VCC range (2.7–3.6 V vs. 4.5–5.5 V). This allows direct substitution in existing layouts when memory size or supply voltage permits, provided software addresses the correct density and configures BP bits accordingly.