Microchip Technology 47L04T-E/ST

Overview

47L04T-E/ST from Microchip Technology is a 4 Kbit I²C serial EERAM combining 512 × 8-bit SRAM with integrated EEPROM backup, operating from 2.7V–3.6V, supporting up to 1 MHz I²C clock, and featuring automatic power-loss store/recall via VCAP capacitor. It delivers infinite SRAM write cycles, >1 million EEPROM store cycles, and >200-year data retention - used in automotive infotainment control modules for volatile parameter caching with nonvolatile persistence.

For engineers reviewing the 47L04T-E/ST datasheet, 47L04T-E/ST pinout, 47L04T-E/ST application, or 47L04T-E/ST equivalent, key selection criteria include I²C timing compliance (1 MHz max), Auto-Store trip voltage (2.4–2.6 V), manual Hardware Store pulse width (≥150 ns), SRAM write protection granularity (down to 1/64 array), and TSSOP-8 package compatibility with industrial (-40°C to +85°C) and extended (-40°C to +125°C) temperature grades.

Technical Context

The 47L04T-E/ST implements a dual-memory architecture where SRAM serves as the primary read/write interface while EEPROM provides high-endurance nonvolatile backup. Its I²C client logic supports standard 7-bit addressing with user-configurable A1/A2 pins and fixed op-code mapping (0x50 for SRAM, 0x30 for control registers).

Power management is hardware- and software-coordinated: Auto-Store triggers on VCC fall below 2.4–2.6 V (with external VCAP capacitor), while manual Store can be initiated via HS pin pulse or software command (0x33). Recall occurs automatically at power-up or via software (0xDD), with status tracking via volatile AM bit and nonvolatile ASE/Event flags in the STATUS register.

Key Specifications

Pinout & Package

47L04T-E/ST is housed in an 8-lead TSSOP (Thin Shrink Small Outline Package) with 0.65 mm lead pitch, JEDEC MO-153 compliant, suitable for automated SMT assembly and space-constrained PCB layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with FM24V04-G and AT24C04D-SSHM-T, the 47L04T-E/ST uniquely balances SRAM-speed access with EEPROM-level nonvolatility through hardware-managed store/recall - making it optimal for systems requiring both low-latency parameter updates and guaranteed power-fail resilience without F-RAM cost premium or EEPROM write bottlenecks.

Availability

47L04T-E/ST is available at Aetrix Electronics and suitable for automotive instrument clusters, industrial PLCs, medical infusion pumps, and smart energy meters requiring stable component supply with AEC-Q100 qualification and extended temperature support.

Supply support for 47L04T-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, with broad automotive and industrial certification coverage.

The 47L04T-E/ST belongs to Microchip's EERAM product line - designed specifically to replace battery-backed SRAM and discrete EEPROM+logic combinations in systems needing transparent, low-power, high-reliability nonvolatile data retention.

FAQ

What is the function of the VCAP pin on the 47L04T-E/ST?

The VCAP pin on the 47L04T-E/ST connects to an external 5–6.8 µF capacitor to enable automatic SRAM-to-EEPROM store during power loss. When VCC falls below the trip voltage (2.4–2.6 V), stored charge on VCAP sustains the store operation for up to 8 ms. If VCAP is unconnected, Auto-Store must be disabled (ASE = 0) and the pin tied to VCC to prevent EEPROM corruption - the 47L04T-E/ST will still support manual Store via HS pin or software command.

How does the 47L04T-E/ST handle write protection of its SRAM array?

The 47L04T-E/ST uses three nonvolatile BP<2:0> bits in its STATUS register to configure software write protection across eight granularity levels - from no protection to full-array lock. For the 4 Kbit density, protected ranges span upper 1/64 (0x1F8–0x1FF) to entire array (0x000–0x1FF). Protection is enforced at the hardware level: writes to locked regions generate NoACK and abort the transaction without incrementing the address pointer - the 47L04T-E/ST ensures firmware cannot overwrite critical configuration data.

Can the 47L04T-E/ST operate on a 1 MHz I²C bus reliably?

Yes, the 47L04T-E/ST fully supports 1 MHz I²C operation per its AC specifications: minimum clock high/low times of 500 ns, rise/fall times ≤300 ns, and input filtering spike suppression ≤50 ns. It meets standard-mode (100 kHz), fast-mode (400 kHz), and fast-mode plus (1 MHz) timing requirements. Successful 1 MHz operation requires proper bus capacitance (<400 pF), appropriate pull-up strength, and adherence to setup/hold timing - the 47L04T-E/ST's Schmitt-trigger inputs enhance noise immunity at high speed.

What is the purpose of the HS pin on the 47L04T-E/ST?

The HS (Hardware Store) pin on the 47L04T-E/ST provides a dedicated, asynchronous method to initiate immediate SRAM-to-EEPROM store - independent of VCAP state or VCC level. A high-going pulse ≥150 ns triggers the store operation, which completes in ≤8 ms. This allows deterministic, host-controlled data persistence (e.g., after critical parameter update) without waiting for power failure. The HS pin also sets the EVENT flag in the STATUS register, enabling external event logging - the 47L04T-E/ST treats HS activation as a priority interrupt overriding ongoing I²C transactions.

Is the 47L04T-E/ST qualified for automotive applications?

Yes, the 47L04T-E/ST carries AEC-Q100 qualification for Extended temperature grade (-40°C to +125°C), meeting stress test requirements for automotive use including HTOL, TCT, and ESD (>4 kV HBM). Its 2.7–3.6 V VCC range aligns with 3.3 V automotive domain controllers, and features like Auto-Store, Hardware Store, and nonvolatile event detection support functional safety goals in instrument clusters, body control modules, and ADAS subsystems - the 47L04T-E/ST is documented in Microchip's automotive product portfolio with PPAP-ready manufacturing.