Microchip Technology 47L16-I/ST

Overview

47L16-I/ST from Microchip Technology is a 16 Kbit (2,048 × 8) I²C serial EERAM combining volatile SRAM with nonvolatile EEPROM backup. It operates from 2.7V–3.6V, supports up to 1 MHz I²C, and delivers automatic power-loss data retention via VCAP capacitor-assisted store/recall. Used in industrial control systems requiring persistent memory without external backup circuitry.

For engineers reviewing the 47L16-I/ST datasheet, 47L16-I/ST pinout, 47L16-I/ST application, or 47L16-I/ST equivalent, this page provides verified functional identity, validated I²C timing compliance, confirmed 8-pin TSSOP package mapping, real-world store/recall latency values, and two field-validated alternative parts for SRAM+EEPROM hybrid memory selection.

Technical Context

The 47L16-I/ST implements a dual-memory architecture: a 2,048 × 8-bit SRAM array for high-speed read/write access and an EEPROM array for nonvolatile backup. Store and recall operations are triggered automatically on power-down/up (with external VCAP capacitor), manually via hardware Store pin (HS), or through software commands (0x33 for Store, 0xDD for Recall).

I²C interface complies with standard 100 kHz/400 kHz/1 MHz modes, features Schmitt-trigger inputs for noise immunity, and supports cascading up to four devices using A1/A2 address pins. The STATUS register (address 0x00) enables software write protection across 1/64 to full array and controls Auto-Store Enable (ASE) and Array Modified (AM) flags.

Key Specifications

Pinout & Package

47L16-I/ST is housed in an 8-lead TSSOP (Thin Shrink Small Outline Package) with 0.65 mm lead pitch, surface-mount compatible, and RoHS-compliant.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar SRAM+EEPROM hybrid memory applications.

Compared with 47L16-I/ST, FM24V10-G eliminates store latency and endurance limits but adds SPI complexity and removes automatic power-loss response, while AT24C128C-SSHL-T increases firmware overhead and system-level failure risk by decoupling volatile and nonvolatile memory functions.

Availability

47L16-I/ST is available at Aetrix Electronics and suitable for industrial automation, medical instrumentation, automotive body electronics, and smart metering applications requiring stable component supply across extended product lifecycles.

Supply support for 47L16-I/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 is a leading provider of microcontrollers, analog, FPGA, and memory solutions, serving industrial, automotive, and communications markets with high-reliability silicon and development tools.

The 47L16-I/ST belongs to Microchip's EERAM family - designed specifically to replace battery-backed SRAM and simplify nonvolatile data retention in resource-constrained embedded systems using standard I²C infrastructure.

FAQ

What is the function of the VCAP pin on the 47L16-I/ST?

The VCAP pin on the 47L16-I/ST connects to an external 8–10 µF capacitor to enable automatic SRAM-to-EEPROM store during power-down. When VCC drops below the 2.4–2.6 V trip threshold (VTRIP), the device uses residual charge on VCAP to complete the 25 ms store operation. If VCAP is omitted, the ASE bit must be disabled to prevent EEPROM corruption - the 47L16-I/ST will not function in auto-store mode without this capacitor.

How does the 47L16-I/ST handle I²C address conflicts when multiple devices share the bus?

The 47L16-I/ST uses two hardware address pins (A1 and A2) to configure its 3-bit chip select (A2/A1/0), allowing up to four devices on the same I²C bus. Each device responds only when its A1/A2 pin states match the corresponding bits in the received control byte (0x50–0x53 for SRAM writes). The fixed '0' bit in position 1 ensures no conflict with standard EEPROM addresses, and Schmitt-trigger inputs prevent metastability during address arbitration.

Can the 47L16-I/ST be used without the hardware store (HS) pin connected?

Yes - the 47L16-I/ST operates fully without the HS pin connected. Store operations can be initiated via software command (0x33 to COMMAND register) or automatically using the VCAP capacitor. The HS pin is optional and serves only to provide a hardware-triggered, deterministic store independent of I²C bus activity. Leaving HS unconnected disables only this specific feature; all other functionality - including auto-store, recall, and SRAM access - remains fully operational in the 47L16-I/ST.

What is the purpose of the AM (Array Modified) bit in the 47L16-I/ST STATUS register?

The AM bit in the 47L16-I/ST STATUS register (bit 7) is a volatile flag indicating whether the SRAM array has been written since the last store or recall operation. It is set to '1' on any SRAM write and cleared only upon completion of a successful store or recall. The AM bit must be '1' to enable auto-store or hardware store - it acts as a hardware-enforced guard preventing unnecessary EEPROM writes when data is unchanged, thereby preserving EEPROM endurance in the 47L16-I/ST.

Does the 47L16-I/ST support write protection of partial memory regions?

Yes - the 47L16-I/ST supports granular software write protection via BP<2:0> bits (bits 4–2) in the STATUS register. These bits configure protection for 1/64 (7E0h–7FFh), 1/32 (7C0h–7FFh), up to full-array (000h–7FFh) ranges of its 2,048-byte SRAM. Protection is enforced at the hardware level: writes to locked regions generate no ACK and abort the transaction. This feature is nonvolatile and persists across power cycles, making it ideal for safeguarding calibration constants or firmware parameters in the 47L16-I/ST.