MIC2291YD5

LED Driver IC Overview

The MIC2291YD5 is a 1.2MHz pulse-width modulation (PWM) boost-switching regulator optimized for high-current white LED photo flash applications. It features a guaranteed switch current of 1.2A, enabling it to drive a string of three white LEDs in series at 100mA. The device operates with a constant frequency PWM control scheme, which reduces noise and input ripple compared to variable frequency topologies. It includes over-voltage protection options for 15V and 34V output limits. The component supports an input voltage range of 2.5V to 10V and offers a shutdown current of 1µA. It is available in low-profile Thin SOT23-5 and 2mm x 2mm MLF® packages, with a junction temperature range of -40°C to +125°C.

LED Driver IC Feature Summary

• Implements constant frequency 1.2MHz PWM control to minimize noise and input ripple injected back to the battery source.
• Optimized efficiency through a 95mV feedback voltage setting, reducing power dissipation in the current set resistor.
• Provides selectable over-voltage protection levels at 15V and 34V to allow selection of appropriately rated external components.
• Features ultra-low shutdown current of 1µA and over-temperature protection for reliable operation.

LED Driver IC Applications

• High-current white LED photo flash drivers
• Portable electronic devices requiring compact LED illumination
• Battery-powered systems needing efficient step-up regulation

LED Driver IC Procurement Notes

Verify the specific suffix (e.g., YD5 vs. YML) to confirm package type and over-voltage protection rating. Ensure the ordering part number matches the required output voltage limit (15V or 34V). Confirm manufacturer origin as Microchip Technology, following the acquisition of Micrel. Check datasheet revisions for any updates on thermal characteristics or pin configurations before finalizing procurement.

LED Driver IC Selection Notes

Select this component when driving multiple series-connected white LEDs requires high efficiency and low noise. The choice between 15V and 34V OVP depends on the maximum forward voltage of the LED string plus margin. Consider the Thin SOT23-5 package for space-constrained designs where leaded or larger surface-mount packages are unsuitable. Evaluate thermal performance within the -40°C to +125°C range for the intended operating environment.

LED Driver IC Part Context

The MIC2291 belongs to a family of boost regulators designed specifically for LED lighting applications. Originally developed by Micrel Inc., the product line was integrated into Microchip Technology's portfolio. This specific model focuses on photo flash use cases, distinguishing itself from general-purpose DC-DC converters by its optimized feedback voltage and high-frequency PWM operation tailored for LED brightness control.

LED Driver IC Replacement Considerations

Direct substitutes include other models within the MIC2291 family, such as MIC2291-15YML-TR or MIC2291-34YML-TR, depending on the required OVP level and package preference. Verify pin compatibility and electrical parameters against the original design requirements before substitution.

LED Driver IC FAQ

What is the difference between the MIC2291-15 and MIC2291-34 variants?

The primary difference is the over-voltage protection (OVP) threshold. The MIC2291-15 variant clamps the output at 15V, while the MIC2291-34 variant allows outputs up to 34V before triggering protection.

How does the MIC2291 reduce noise compared to other regulators?

It uses a constant frequency 1.2MHz PWM control scheme, which prevents the wide frequency spread associated with variable frequency topologies, thereby significantly lowering noise and input ripple.