Microchip Technology 47C04-E/SN

Overview

47C04-E/SN from Microchip Technology is a 4 Kbit I²C serial EERAM (SRAM with integrated EEPROM backup), organized as 512 × 8 bits, operating from 4.5V–5.5V, supporting up to 1 MHz I²C interface, and featuring automatic power-loss store/recall via external capacitor. It serves as nonvolatile data buffer in industrial control systems requiring high endurance and zero-cycle-delay memory access.

For engineers reviewing the 47C04-E/SN datasheet, 47C04-E/SN pinout, 47C04-E/SN application, or 47C04-E/SN equivalent, this page delivers verified electrical specs, validated I²C timing behavior, confirmed SRAM/EEPROM interaction logic, exact package mapping to SOIC-8, and two rigorously cross-checked alternative parts for design continuity.

Technical Context

The 47C04-E/SN implements a dual-memory architecture: volatile SRAM (512 × 8) for fast read/write access and nonvolatile EEPROM (same density) for retention. Store and recall operations are triggered either automatically on VCC fall below 4.0–4.4 V (VTRIP), manually via HS pin pulse ≥150 ns, or through software commands (0x55 + 0x33 for Store, 0x55 + 0xDD for Recall).

I²C communication uses standard 7-bit client addressing with A1/A2 pins defining device address; op codes 0xA0/0xA1 select SRAM, 0x30/0x31 select control registers. The STATUS register (address 0x00) manages BP<2:0> write protection, ASE auto-store enable, AM array-modified flag, and EVENT detection - all nonvolatile except AM.

Key Specifications

Pinout & Package

47C04-E/SN is housed in an 8-lead SOIC (Small Outline Integrated Circuit) package, pin-compatible with PDIP and TSSOP variants. The SOIC-8 footprint (JEDEC MS-012) measures 3.9 mm × 4.9 mm with 1.27 mm pitch, suitable for automated SMT assembly and space-constrained PCBs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 47C04-E/SN, 47L04-E/SN offers identical functionality at 3.3 V with lower trip voltage, while FM24V04-G replaces EEPROM backup with F-RAM for infinite endurance but removes the HS pin and VCAP-based auto-store - making it unsuitable for deterministic power-loss capture in 5 V systems.

Availability

47C04-E/SN is available at Aetrix Electronics and suitable for industrial PLC data logging, automotive body control modules, medical infusion pump calibration, and smart energy meter firmware parameter storage requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for 47C04-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 global semiconductor company specializing in microcontrollers, analog devices, and memory solutions, with a focus on reliability, longevity, and industrial-grade qualification.

The 47C04-E/SN belongs to Microchip's EERAM family - designed specifically to replace battery-backed SRAM and discrete EEPROM+SRAM combinations in mission-critical embedded systems demanding seamless nonvolatility without external components.

FAQ

What is the function of the VCAP pin on the 47C04-E/SN?

The VCAP pin on the 47C04-E/SN connects to an external 3.5–4.7 µF capacitor that supplies hold-up energy during VCC dropout. When VCC falls below the trip voltage (4.0–4.4 V), the 47C04-E/SN uses charge stored on this capacitor to complete an automatic SRAM-to-EEPROM store operation within ≤8 ms. If VCAP is unconnected, Auto-Store must be disabled via the ASE bit to prevent data corruption.

How does the Hardware Store (HS) pin operate on the 47C04-E/SN?

The HS pin on the 47C04-E/SN initiates a manual Store operation when driven high for ≥150 ns. This action forces immediate transfer of modified SRAM contents to EEPROM, independent of VCC level or ASE bit setting. The HS pin is ignored during active Store/Recall operations or when VCAP voltage is below VTRIP, and its assertion also sets the EVENT bit in the STATUS register.

Can the 47C04-E/SN be used in a 3.3 V system?

No - the 47C04-E/SN is specified only for 4.5 V to 5.5 V operation and is not 3.3 V compatible. Attempting to power it from 3.3 V will result in failure to meet VTRIP thresholds, unreliable I²C communication, and undefined store/recall behavior. For 3.3 V systems, use the pin-compatible 47L04-E/SN variant, which operates from 2.7 V to 3.6 V with a 2.4–2.6 V VTRIP range.

What is the purpose of the AM (Array Modified) bit in the 47C04-E/SN STATUS register?

The AM bit in the 47C04-E/SN STATUS register (bit 7, read-only) indicates whether the SRAM array has been written since the last Store or Recall operation: '1' means modified, '0' means synchronized with EEPROM. Auto-Store and Hardware Store require AM = 1 to execute; Software Store runs regardless. The AM bit clears automatically upon completion of any Store or Recall operation.

Does the 47C04-E/SN support I²C clock stretching?

No - the 47C04-E/SN does not implement clock stretching. It performs all internal operations (Store, Recall, STATUS writes) asynchronously and blocks I²C access for defined durations (e.g., ≤8 ms for Store, ≤1 ms for STATUS write). During these blocked periods, the device returns no ACK and ignores incoming commands - requiring host firmware to implement timeout-based retry logic rather than relying on SCL hold.