Microchip Technology 47C04T-E/SN

Overview

47C04T-E/SN from Microchip Technology is a 4 Kbit I²C serial EERAM combining 512 × 8-bit SRAM with integrated EEPROM backup, operating at 4.5–5.5 V and supporting up to 1 MHz I²C clock. It enables automatic power-loss data retention via external VCAP capacitor, supports hardware/software Store/Recall, and delivers infinite SRAM write cycles with >1 million EEPROM store cycles. It is used in industrial control systems requiring nonvolatile memory with fast SRAM access and deterministic power-fail recovery.

For engineers reviewing the 47C04T-E/SN datasheet, 47C04T-E/SN pinout, 47C04T-E/SN application, or 47C04T-E/SN equivalent, key selection criteria include its 4.5–5.5 V supply range, 8 ms max Store time, Schmitt-triggered I²C interface, software-configurable write protection, and AEC-Q100-qualified extended temperature operation (–40°C to +125°C).

Technical Context

The 47C04T-E/SN implements a dual-memory architecture where SRAM serves as the active read/write buffer and EEPROM provides nonvolatile backup. Store operations transfer modified SRAM contents to EEPROM either automatically on VCC fall below 4.0–4.4 V (VTRIP), manually via HS pin pulse ≥150 ns, or through software command (0x33). Recall restores EEPROM data to SRAM on power-up or via software command (0xDD), completing in ≤2 ms.

I²C communication uses fixed 4-bit opcodes (0xA for SRAM, 0x3 for control registers) with user-selectable A1/A2 address bits, supporting up to four devices on one bus. The STATUS register (address 0x00) controls Auto-Store Enable (ASE), Block Protect (BP2–BP0), Array Modified (AM), and Event Detect (EVENT) flags - all nonvolatile except AM, which is cleared after Store/Recall completion.

Key Specifications

Pinout & Package

47C04T-E/SN is housed in an 8-lead SOIC package (SN suffix), with gull-wing leads, 1.27 mm pitch, and JEDEC MS-012AC outline. Pin 1 is marked by a beveled corner or dot; device orientation follows standard SOIC conventions.

Key Features

Applications

Equivalent & Alternatives

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

Compared with FM24CL04B-G and AT24C04D-SSH-T, the 47C04T-E/SN uniquely combines SRAM-speed access, automatic power-loss backup, and AEC-Q100 qualification - making it the only option that eliminates host intervention while meeting automotive and industrial reliability standards.

Availability

47C04T-E/SN is available at Aetrix Electronics and suitable for industrial PLC data logging, automotive telematics event buffering, and medical infusion pump configuration memory requiring stable component supply across extended temperature and long product lifecycles.

Supply support for 47C04T-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, FPGA, and memory solutions, headquartered in Chandler, Arizona, with global design and manufacturing operations.

The 47C04T-E/SN belongs to Microchip's EERAM family - designed specifically for applications needing SRAM-like performance with EEPROM-level nonvolatility, targeting automotive, industrial, and medical systems where power interruption resilience is mandatory.

FAQ

What is the function of the VCAP pin on the 47C04T-E/SN?

The VCAP pin on the 47C04T-E/SN connects to an external 3.5–4.7 µF capacitor that enables automatic Store operation when VCC falls below the trip voltage (4.0–4.4 V). During normal operation, VCAP holds charge; during power loss, its discharge rate triggers SRAM-to-EEPROM transfer. If VCAP is omitted, the pin must be tied to VCC and Auto-Store disabled via the ASE bit to prevent EEPROM corruption.

How does the 47C04T-E/SN differ from a standard I²C EEPROM like the AT24C04D?

The 47C04T-E/SN integrates both SRAM and EEPROM in one die with seamless Store/Recall logic, enabling zero-latency reads/writes to SRAM and deterministic nonvolatile backup. In contrast, the AT24C04D is EEPROM-only with 5 ms write latency per byte, no SRAM buffer, no hardware Store pin, and no automatic power-loss response - requiring full host software management of data persistence.

Can the 47C04T-E/SN operate without an external capacitor?

Yes - the 47C04T-E/SN can operate without an external VCAP capacitor if Auto-Store is disabled (ASE = 0) and the VCAP pin is connected directly to VCC. In this mode, Store operations rely solely on software commands (0x33) or the HS pin. However, automatic power-loss protection is forfeited, and the device functions as a standard I²C SRAM with optional EEPROM backup initiated only on demand.

What is the purpose of the HS pin on the 47C04T-E/SN?

The HS (Hardware Store) pin on the 47C04T-E/SN provides a direct, asynchronous method to initiate SRAM-to-EEPROM transfer: a high pulse ≥150 ns triggers immediate Store regardless of VCC level, ASE setting, or AM flag state. This enables precise, host-controlled data capture - for example, logging a critical fault event before system shutdown - with guaranteed execution within 8 ms.

Is the 47C04T-E/SN pin-compatible with other devices in the 47XXX family?

Yes - the 47C04T-E/SN shares identical 8-lead SOIC (SN) pinout, I²C addressing scheme, and register map with all 47XXX variants (47L04, 47C16, etc.). Differences lie in density (4 Kbit vs. 16 Kbit), supply range (4.5–5.5 V vs. 2.7–3.6 V), and VTRIP voltage (4.0–4.4 V vs. 2.4–2.6 V), but PCB layout and firmware drivers remain interchangeable across the family when configured for the same density and voltage domain.