Microchip Technology 11LC161T-I/SN

Overview

11LC161T-I/SN from Microchip Technology is a 16 Kbit (2,048 × 8) serial EEPROM with UNI/O® single I/O bus interface, operating from 2.5V to 5.5V over -40°C to +85°C industrial temperature range. It features 16-byte page write buffer, STATUS register with WIP/WEL bits, and hardware block write protection for 0%, 25%, 50%, or 100% of memory array - used in embedded system configuration storage, sensor calibration data retention, and firmware parameter backup.

For engineers reviewing the 11LC161T-I/SN datasheet, 11LC161T-I/SN pinout, 11LC161T-I/SN application, or 11LC161T-I/SN equivalent, key selection considerations include its 3-lead SOT-23 package compatibility, 100 kbps UNI/O® bit rate, 1 µA max standby current, Schmitt-trigger SCIO input for noise immunity, and device address 0xA1 enabling coexistence with 0xA0-addressed 11LC160 on same bus.

Technical Context

The 11LC161T-I/SN implements Manchester-encoded UNI/O® protocol over a single bidirectional SCIO line, eliminating need for separate clock and data lines. Its internal timing recovery circuitry tolerates ±0.50% frequency drift per byte and ±0.06 UI edge jitter, enabling robust communication with low-cost GPIO-based masters.

It integrates a current-limited slope-controlled SCIO driver, Schmitt-trigger input stage, and auto-erase/self-timed write cycle (5–10 ms). Memory organization is fixed at 2,048 × 8 bits with 16-byte page boundaries; write operations wrap within page but do not cross physical page boundaries.

Key Specifications

Pinout & Package

11LC161T-I/SN is packaged in 3-lead SOT-23 (SN suffix), with SCIO as bidirectional serial I/O, VCC as supply input, and VSS as ground reference. No NC pins are present in this variant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 11AA161T-I/SN, the 11LC161T-I/SN trades 1.8V operation for guaranteed 5V tolerance and simpler voltage domain integration; versus 25AA160AT-I/SN, it saves two PCB traces and enables direct GPIO control but requires UNI/O®-capable firmware stack.

Availability

11LC161T-I/SN is available at Aetrix Electronics and suitable for industrial sensor calibration, motor drive configuration backup, and IoT edge device identity storage requiring stable component supply across extended production lifecycles.

Supply support for 11LC161T-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 U.S.-based semiconductor manufacturer specializing in microcontrollers, analog devices, and memory products for industrial, automotive, and consumer applications.

The 11LC161T-I/SN belongs to Microchip's UNI/O® serial EEPROM family, designed specifically for cost-sensitive, space-constrained embedded systems needing minimal pin count and ultra-low standby power.

FAQ

What is the device address of the 11LC161T-I/SN on the UNI/O® bus?

The 11LC161T-I/SN has a fixed device address of 0xA1 (1010 0001 binary), where the family code '1010' is common to all 11XX devices and the device code '0001' distinguishes it from 0xA0-addressed variants like 11LC160. This allows both part numbers to coexist on the same UNI/O® bus without conflict, enabling flexible memory expansion in multi-device systems using the 11LC161T-I/SN.

Does the 11LC161T-I/SN support write protection at the hardware level?

Yes, the 11LC161T-I/SN implements hardware block write protection via BP0 and BP1 bits in its STATUS register. These nonvolatile bits enable permanent or dynamic locking of 0%, 25%, 50%, or 100% of the memory array - for example, protecting the first 512 bytes containing bootloader configuration while allowing runtime updates to the remaining 1,536 bytes. This protection persists through power cycles and is enforced independently of software control, ensuring robustness in the 11LC161T-I/SN.

What is the maximum write speed and timing behavior of the 11LC161T-I/SN?

The 11LC161T-I/SN supports up to 100 kbps UNI/O® bit rate, with self-timed write cycles completing in 5 ms (byte) or 10 ms (page). During write, the Write-In-Progress (WIP) bit in the STATUS register asserts high and must be polled until cleared - no external wait states or clocks are required. This autonomous timing ensures deterministic behavior in the 11LC161T-I/SN across voltage and temperature ranges without host-side timing calibration.

Can the 11LC161T-I/SN be used with a 1.8V microcontroller?

No, the 11LC161T-I/SN operates only from 2.5V to 5.5V and is not rated for 1.8V logic levels. Attempting to interface it with a 1.8V MCU may result in unreliable SCIO communication due to insufficient VIH/VIL margins. For 1.8V systems, use the pin-compatible 11AA161T-I/SN instead - it shares identical density, UNI/O® protocol, and 0xA1 address but supports 1.8–5.5V operation, making it the correct functional alternative to the 11LC161T-I/SN in low-voltage designs.

What package type does the 11LC161T-I/SN use, and what are its PCB layout requirements?

The 11LC161T-I/SN uses the 3-lead SOT-23 package (indicated by 'SN' suffix), with pin 1 = SCIO, pin 2 = VSS, pin 3 = VCC. Layout requires a solid ground plane beneath the package, 100 nF ceramic decoupling capacitor placed ≤5 mm from VCC–VSS, and SCIO trace length minimized (<5 cm) with no stubs to preserve UNI/O® signal integrity. This compact footprint supports high-density layouts in the 11LC161T-I/SN without compromising timing margin or ESD robustness.