MCP1643-I/MS

LED Driver IC Overview

The MCP1643-I/MS is a 1 MHz low start-up voltage synchronous boost LED constant current regulator manufactured by Microchip Technology. It operates from an input voltage range of 0.6V to 5.5V and delivers a maximum output current of 0.55A. The device features fixed-frequency synchronous step-up conversion optimized for driving single LEDs with constant current. It includes output overvoltage protection limiting voltage to 5.0V typical during LED failure or load disconnection. Packaged in MSOP-8, it supports surface mount mounting and functions within an operating temperature range of -40°C to 85°C.

LED Driver IC Feature Summary

• Synchronous step-up converter architecture optimized for high-efficiency constant current LED driving
• Integrated output overvoltage protection limits voltage to 5.0V typical during fault conditions
• Low start-up voltage capability enables operation from single or dual-cell battery sources
• Fixed 1 MHz switching frequency allows for compact external component sizing

LED Driver IC Applications

• One- and two-cell alkaline portable LED lighting products
• LED flashlights and headlamps
• Rechargeable flashlight systems using NiMH/NiCd batteries
• General LED constant current regulation applications

LED Driver IC Procurement Notes

Verify the specific suffix 'I/MS' confirms industrial temperature range (-40°C to 85°C) and MSOP-8 package type. Confirm datasheet revision matches design requirements. Ensure supply chain authenticity through authorized Microchip distributors. Check for RoHS compliance status if required by target market regulations. Validate pinout compatibility with existing PCB footprints before finalizing procurement orders.

LED Driver IC Selection Notes

Select this component when low input voltage operation from single-cell sources is required alongside high efficiency. The synchronous design reduces external inductor size compared to non-synchronous alternatives. Verify that the 0.55A max output current meets the target LED drive requirements. Consider the 1 MHz frequency for minimizing passive component footprint. Ensure thermal management aligns with the MSOP-8 package capabilities under expected load conditions.

LED Driver IC Part Context

This part belongs to Microchip's MCP164x family of LED drivers. It is specifically designed as a compact solution for portable lighting where battery life and size are critical constraints. The synchronous topology distinguishes it from earlier generation non-synchronous boost converters, offering improved efficiency at light loads. It serves as a dedicated constant current source rather than a general-purpose voltage regulator.

LED Driver IC Replacement Considerations

Direct substitutes include other MCP1643 variants with different temperature grades or packages, such as MCP1643T-I/MS. Cross-family replacements require verification of pin compatibility and electrical parameters. Ensure any alternative maintains the 1 MHz switching frequency and synchronous architecture to preserve board layout integrity.