Microchip Technology 47L04-E/SN

Overview

47L04-E/SN from Microchip Technology is a 4 Kbit I²C serial EERAM (SRAM with integrated EEPROM backup), organized as 512 × 8 bits, operating from 2.7V–3.6V, supporting up to 1 MHz I²C interface, and featuring automatic power-loss data retention via VCAP capacitor-assisted store/recall. It serves as nonvolatile memory buffer in industrial control modules where SRAM speed and EEPROM endurance are jointly required.

For engineers reviewing the 47L04-E/SN datasheet, 47L04-E/SN pinout, 47L04-E/SN application, or 47L04-E/SN equivalent, key selection considerations include its 8 ms max store time, 200 µA typical active current, software/hardware store control, ASE/AM status register management, and AEC-Q100-qualified extended temperature operation (–40°C to +125°C).

Technical Context

The 47L04-E/SN implements a dual-memory architecture: volatile SRAM for high-speed read/write access and nonvolatile EEPROM for data persistence. Its I²C client interface uses standard 7-bit addressing with user-configurable A1/A2 pins and supports byte/sequential reads/writes with zero-cycle-delay timing.

Store and recall operations are triggered either automatically on VCC fall below VTRIP (2.4–2.6 V), manually via HS pin pulse (≥150 ns), or through software commands (0x55 + 0x33 for Store, 0x55 + 0xDD for Recall). The STATUS register (address 0x00) provides real-time AM (Array Modified), ASE (Auto-Store Enable), and EVENT flag control with nonvolatile BP bits for 1/64–full-array write protection.

Key Specifications

Pinout & Package

47L04-E/SN is supplied in an 8-lead SOIC package (SN suffix), with gull-wing leads, 1.27 mm pitch, and JEDEC MS-012AC footprint. Pin functions are electrically validated per DS20005371E.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 47L04-I/SN, the 47L04-E/SN adds AEC-Q100 qualification and extended temperature support; compared with FM24V04-G, it trades F-RAM's zero-write-latency for integrated event detection and capacitor-based auto-store - making it optimal for automotive and industrial systems requiring hardware-triggered persistence.

Availability

47L04-E/SN is available at Aetrix Electronics and suitable for industrial PLC data logging, automotive body control modules, and smart energy meter firmware state retention requiring stable component supply across multi-year production cycles.

Supply support for 47L04-E/SN 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 infrastructure.

The 47L04-E/SN belongs to Microchip's EERAM product line, designed specifically to replace battery-backed SRAM and discrete SRAM+EEPROM combinations in systems demanding both high-speed access and guaranteed nonvolatile storage without external supervision.

FAQ

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

The VCAP pin on the 47L04-E/SN connects to an external 5–6.8 µF capacitor to enable automatic SRAM-to-EEPROM store during power loss. When VCC drops below the trip voltage (2.4–2.6 V), charge stored in the capacitor sustains the device long enough to complete the ≤8 ms store operation. If unused, VCAP must be tied to VCC and ASE disabled to prevent EEPROM corruption - a requirement explicitly defined in DS20005371E.

How does the 47L04-E/SN differ from standard I²C EEPROMs?

Unlike standard I²C EEPROMs, the 47L04-E/SN integrates a 512 × 8-bit SRAM array with instant read/write access and an on-chip EEPROM backup. It supports zero-cycle-delay I²C reads/writes to SRAM, while EEPROM is used only for persistence - eliminating EEPROM write latency during normal operation. The 47L04-E/SN also provides hardware store (HS pin), status register (AM/ASE/EVENT), and configurable write protection absent in basic EEPROMs.

Can the 47L04-E/SN operate without an external capacitor?

Yes, the 47L04-E/SN can operate without an external capacitor only if Auto-Store is disabled (ASE = 0) and VCAP is hard-wired to VCC. In this mode, store and recall operations rely solely on software commands (0x55+0x33 / 0x55+0xDD) or the HS pin. However, power-loss data retention is forfeited - making capacitor omission acceptable only in systems with controlled shutdown sequences or redundant backup mechanisms.

What does the AM bit in the STATUS register indicate for the 47L04-E/SN?

The AM (Array Modified) bit in the 47L04-E/SN STATUS register (bit 7, read-only) indicates whether the SRAM contents differ from the EEPROM backup: AM = 1 means at least one write has occurred since the last store or recall, enabling auto-store and hardware store functions. AM is cleared automatically upon completion of any store or recall operation and cannot be written directly - it serves as a hardware-enforced dirty-bit flag essential for deterministic persistence control.

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

Yes, the 47L04-E/SN is pin-compatible with all 47XXX variants (47C04, 47L16, 47C16) in the same package type (e.g., SOIC-8 SN), sharing identical pinout, I²C protocol, and register map. However, density (4K vs. 16K), VCC range (2.7–3.6V vs. 4.5–5.5V), and store time (8 ms vs. 25 ms) differ - requiring firmware validation of address boundaries and timing constraints when substituting across family members.