Microchip Technology 47C04T-I/SN

Overview

47C04T-I/SN from Microchip Technology is a 4 Kbit I²C serial EERAM combining SRAM (512 × 8) with EEPROM backup, supporting automatic power-loss data retention via VCAP capacitor, hardware Store pin (HS), and software-controlled Store/Recall commands. It operates at 4.5–5.5 V, delivers 1 MHz I²C interface speed, and targets industrial data logging and configuration storage in embedded controllers.

For engineers reviewing the 47C04T-I/SN datasheet, 47C04T-I/SN pinout, 47C04T-I/SN application, or 47C04T-I/SN equivalent, key selection criteria include its 8 ms max Store time, 2 ms Recall duration, nonvolatile STATUS register with ASE/AM bits, Schmitt-triggered SDA/SCL inputs, and AEC-Q100-qualified temperature range (–40°C to +85°C).

Technical Context

The 47C04T-I/SN implements a dual-memory architecture: volatile SRAM for high-speed read/write access and nonvolatile EEPROM for long-term backup. Its I²C client interface uses fixed 4-bit opcodes (1010 for SRAM, 0011 for control registers) with user-configurable A1/A2 address bits and R/W bit-driven operation mode selection.

Store and Recall operations are triggered by three independent mechanisms: automatic voltage-drop detection (VTRIP = 4.0–4.4 V), hardware pulse on HS pin (min 150 ns), or software command writes to COMMAND register (0x55). The STATUS register (0x00) provides real-time AM flag tracking and BP2:BP0 software write protection granularity down to 1/64 of the 512-byte array.

Key Specifications

Pinout & Package

47C04T-I/SN is housed in an 8-lead SOIC package (SN suffix), with gull-wing leads, 1.27 mm pitch, and JEDEC MS-012AC compliant footprint.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 47C04T-I/SN, 47L04-I/SN trades 5 V compatibility for 3.3 V optimization and higher temperature grade, while FM24CL04B-G replaces EEPROM backup with F-RAM's inherent nonvolatility-simplifying design but removing voltage-threshold-controlled auto-store behavior critical for fail-safe data capture.

Availability

47C04T-I/SN is available at Aetrix Electronics and suitable for industrial automation, automotive body electronics, and medical device applications requiring stable component supply, long-term lifecycle support, and AEC-Q100-compliant nonvolatile memory.

Supply support for 47C04T-I/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 embedded system integration.

The 47C04T-I/SN belongs to Microchip's EERAM product line, engineered specifically for applications needing seamless SRAM-like performance with EEPROM-level data retention-bridging the gap between volatile and nonvolatile memory in resource-constrained embedded systems.

FAQ

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

The VCAP pin on the 47C04T-I/SN connects to an external 3.5–4.7 µF capacitor that supplies temporary energy during VCC collapse, enabling the device to autonomously execute SRAM-to-EEPROM Store within ≤8 ms before VCC falls below 4.0 V. If Auto-Store is disabled (ASE = 0), VCAP must be tied to VCC to prevent EEPROM corruption. The 47C04T-I/SN relies on this pin for deterministic, host-free data preservation during unexpected power loss.

How does the Hardware Store (HS) pin operate on the 47C04T-I/SN?

The HS pin on the 47C04T-I/SN initiates an immediate SRAM-to-EEPROM Store upon receiving a high-going pulse ≥150 ns wide. This operation executes regardless of the ASE or AM bit state and suspends all I²C activity until completion (≤8 ms). The HS pin is ignored when VCAP voltage falls below VTRIP (4.0 V) or during active Store/Recall sequences. Its use ensures deterministic, externally triggered data backup synchronized to system events like shutdown signals or watchdog timeouts in the 47C04T-I/SN.

Can the 47C04T-I/SN be used in a 3.3 V system?

No, the 47C04T-I/SN is specified only for 4.5–5.5 V operation and is incompatible with 3.3 V systems. Attempting to power it at 3.3 V will result in undefined behavior, failed I²C communication, and inability to meet VTRIP (4.0–4.4 V) threshold for Auto-Store. For 3.3 V designs, Microchip's 47L04-I/SN (2.7–3.6 V, VTRIP = 2.4–2.6 V) is the functionally equivalent alternative. The 47C04T-I/SN must be used exclusively in 5 V domains.

What is the purpose of the AM (Array Modified) bit in the 47C04T-I/SN STATUS register?

The AM bit in the 47C04T-I/SN STATUS register (bit 7, read-only) indicates whether the SRAM contents differ from the EEPROM backup: '1' means at least one byte has been written since the last Store or Recall, '0' means they match. The AM bit is automatically set on any SRAM write and cleared upon successful Store/Recall completion. It gates Auto-Store and Hardware Store execution-both require AM = 1-and enables firmware to skip unnecessary Store operations, optimizing EEPROM endurance in the 47C04T-I/SN.

How many devices can be cascaded on a single I²C bus using the 47C04T-I/SN?

Up to four 47C04T-I/SN devices can be cascaded on a single I²C bus using unique combinations of the A1 and A2 pins to configure distinct 7-bit slave addresses. Each device uses the base opcode 1010 followed by A2, A1, and fixed 0, yielding four possible addresses: 1010000, 1010001, 1010010, and 1010011. This addressing scheme eliminates address conflicts and allows shared SCL/SDA routing without external multiplexers-enabling scalable memory expansion in compact embedded systems using the 47C04T-I/SN.