48LM01T-I/SM

Overview

The Microchip Technology 48LM01T-I/SM is a 1-Mbit (131,072 x 8 bit) Serial EERAM featuring an SRAM core with hidden EEPROM backup. It utilizes a high-speed SPI interface supporting up to 66 MHz and operates within a voltage range of 2.7V to 3.6V. The device provides unlimited read/write cycles for the SRAM array while automatically mirroring data to nonvolatile EEPROM during power disruptions. It includes a 16-byte nonvolatile user space and supports industrial temperature ranges from -40°C to +85°C.

Feature Summary

• Combines high-speed SRAM performance with nonvolatile EEPROM backup in each memory cell
• Features invisible-to-user automatic data transfer upon power loss or brown-out events
• Includes a dedicated 16-byte nonvolatile user space separate from the main memory array
• Supports standard SPI communication with Schmitt Trigger inputs for noise suppression

Applications

• Data logging systems requiring persistent storage without complex wear-leveling algorithms
• Industrial control applications needing fast access with guaranteed data retention during power failures
• Embedded systems utilizing microcontrollers lacking onboard nonvolatile memory
• Battery-powered devices requiring low standby current and hibernate modes

Procurement Notes

Verify the specific suffix 'I/SM' corresponds to the Industrial temperature grade (-40°C to +85°C) and the 8-lead SOIJ package format. Confirm that the required external VCAP capacitor (typically 47μF to 100 μF) is included in the system design, as it is mandatory for the AutoStore/AutoRecall functionality. Ensure the host controller supports the required SPI Modes 0 and 3 for proper synchronization.

Selection Notes

Select this component when symmetrical read/write speeds are critical alongside nonvolatile data retention. It serves as a drop-in replacement for standard SRAM where data persistence is required without software overhead. Consider the 16-byte nonvolatile user space for storing configuration parameters. Evaluate the 66 MHz SPI speed against the host controller's maximum clock frequency to ensure compatibility.

Part Context

The 48LM01 is part of the 48LXXX family of Serial EERAMs, which integrates SRAM and EEPROM technologies. This family eliminates the need for external battery backups or complex flash management controllers. The 48LM01 specifically offers double the density of the 48L512 variant, providing 131,072 x 8 bits of addressable memory in a compact 8-lead package.

Replacement Considerations

Public confirmed substitute: 48L512T-I/SM (lower density variant).

FAQ

How does the device handle data preservation during a power failure?

The device monitors the VCC level. If VCC drops below a threshold, it uses energy stored in the external VCAP capacitor to automatically transfer all SRAM data to the hidden EEPROM array before power is fully lost.

Can the user directly access the EEPROM backup memory?

No, the EEPROM backup is invisible to the user and cannot be accessed independently. Data transfers occur automatically on power disruption or via specific Software Store commands.

What is the purpose of the HOLD pin?

The HOLD pin allows the user to pause serial communication mid-sequence without resetting the clock or losing the current state. It suspends I/O operations while keeping the device selected.