Microchip Technology 47C04T-E/ST

Overview

47C04T-E/ST from Microchip Technology is a 4 Kbit I²C serial EERAM combining SRAM (512 × 8) with EEPROM backup, supporting automatic power-loss store/recall via VCAP capacitor, hardware Store pin (HS), and software commands. It operates at 4.5–5.5 V, delivers 1 MHz I²C interface with Schmitt-trigger inputs, and targets industrial data logging in programmable logic controllers.

For engineers reviewing the 47C04T-E/ST datasheet, 47C04T-E/ST pinout, 47C04T-E/ST application, or 47C04T-E/ST equivalent, key selection criteria include VCC range compatibility (4.5–5.5 V), Auto-Store trip voltage (4.0–4.4 V), 8 ms max Store time, 2 ms Recall duration, and TSSOP-8 package footprint for space-constrained embedded control designs.

Technical Context

The 47C04T-E/ST implements a dual-memory architecture: volatile SRAM enables infinite read/write cycles, while nonvolatile EEPROM provides >1 million store cycles and >200-year data retention. Its I²C client interface uses fixed 4-bit op code '1010' for SRAM access and '0011' for control registers, with A1/A2 pins enabling up to four devices on one bus.

Auto-Store activation requires external VCAP capacitance (3.5–4.7 µF), and the STATUS register (address 00h) controls BP bits for 1/64–full-array write protection, ASE bit for Auto-Store enable/disable, and AM bit to track SRAM modification status - all nonvolatile except AM.

Key Specifications

Pinout & Package

47C04T-E/ST is housed in an 8-lead TSSOP (Thin Shrink Small Outline Package) with 0.65 mm lead pitch, optimized for automated SMT assembly and thermal performance in compact industrial modules.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 47C04T-E/ST, the 47L04T-E/ST enables 3.3 V system integration but sacrifices 5 V compatibility, while the FM24V04-G removes capacitor dependency and boosts endurance but abandons hardware-triggered store and event detection - making 47C04T-E/ST optimal for robust 5 V industrial control with deterministic power-fail response.

Availability

47C04T-E/ST is available at Aetrix Electronics and suitable for industrial automation, smart metering, and motor control applications requiring stable component supply, long-term lifecycle support, and AEC-Q100-qualified reliability.

Supply support for 47C04T-E/ST 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 U.S.-based semiconductor company specializing in microcontrollers, analog devices, and memory solutions for industrial, automotive, and communications markets.

The 47C04T-E/ST belongs to Microchip's EERAM product line, engineered specifically for applications needing seamless SRAM volatility with EEPROM nonvolatility - bridging the gap between battery-backed RAM and standard serial EEPROM.

FAQ

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

The VCAP pin on the 47C04T-E/ST connects to an external 3.5–4.7 µF capacitor to enable Auto-Store functionality. When VCC drops below the trip voltage (4.0–4.4 V), stored charge on VCAP sustains internal circuitry long enough to automatically transfer SRAM contents to EEPROM. If Auto-Store is disabled, VCAP must be tied to VCC to prevent data corruption - a requirement explicitly defined in DS20005371E.

Can the 47C04T-E/ST operate with a 3.3 V supply?

No, the 47C04T-E/ST cannot operate with a 3.3 V supply. Its specified VCC range is strictly 4.5 V to 5.5 V, as confirmed in the Device Selection Table and DC Characteristics section of DS20005371E. For 3.3 V systems, Microchip offers the pin-compatible 47L04T-E/ST variant, which uses a 2.7–3.6 V range and different Auto-Store trip voltage.

How does the Hardware Store (HS) pin differ from Software Store commands on the 47C04T-E/ST?

The HS pin on the 47C04T-E/ST triggers an immediate, asynchronous SRAM-to-EEPROM store upon a ≥150 ns high pulse, independent of the STATUS register's ASE or AM bits. In contrast, Software Store requires I²C transaction to the COMMAND register (0x55, 0x33) and is subject to bus arbitration and host timing - making HS essential for time-critical fault-response scenarios where MCU may be unresponsive.

What is the maximum I²C clock frequency supported by the 47C04T-E/ST?

The 47C04T-E/ST supports I²C clock frequencies up to 1 MHz, as verified in Table 1-2 (AC Characteristics) of DS20005371E. This allows high-speed configuration loading and parameter updates - significantly faster than legacy 100 kHz EEPROMs - while maintaining full compatibility with standard I²C protocol timing requirements including setup/hold times and bus free intervals.

Is the 47C04T-E/ST qualified for automotive applications?

Yes, the 47C04T-E/ST is AEC-Q100 qualified for automotive applications, as stated in the "Features" section of DS20005371E. It is rated for the Extended temperature range (–40°C to +125°C) and meets stress-test requirements for humidity, thermal cycling, and ESD (>4 kV). This qualification validates its use in engine control units, body electronics, and ADAS subsystems where reliability under harsh conditions is mandatory.