SC443ULTRT LED Driver IC Equivalent & Substitute Parts

Part Overview

The SC443ULTRT is a LED Driver IC manufactured by Semtech Corporation, designed as a 3-output DC-DC regulator with step-up (boost) topology and PWM dimming capability. This component operates at 800kHz switching frequency with a maximum output current of 30mA per channel and supports input voltages from 4.5V to 27V, delivering up to 42V output. The device is classified as obsolete, making identification of functionally equivalent alternatives essential for ongoing design support and production continuity.

Substiute Parts

SC443ULTRT

Semtech CorporationIn Stock: 21369SC443ULTRT Datasheet

Current PartRFQ

ISL97683IRTZ-TK

Renesas Electronics CorporationIn Stock: 1449ISL97683IRTZ-TK Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the SC443ULTRT is determined by the following critical parameters:

• Topology & Function: Step-up (boost) DC-DC regulator with 3 independent outputs
• Dimming Control: PWM-based dimming capability
• Electrical Specifications: Input voltage range, output voltage capability, and per-channel current rating
• Package Compatibility: 16-pin QFN form factor with exposed pad
• Operating Temperature Range: -40°C to 85°C
• Internal Integration: Integrated switching element

The ISL97683IRTZ-TK from Renesas Electronics Corporation meets these core functional requirements while operating as an active product with enhanced specifications in several parameters.

Parameter Comparison

Engineering Selection Recommendations

The ISL97683IRTZ-TK qualifies as a functional substitute for the SC443ULTRT based on matching core topology, output configuration, dimming control method, and operating temperature range. Key considerations for selection:

Product Status: The ISL97683IRTZ-TK is actively manufactured by Renesas Electronics Corporation, providing long-term availability and supply chain stability compared to the obsolete SC443ULTRT.

Compliance & Certifications: The ISL97683IRTZ-TK carries ROHS3 compliance and REACH unaffected status, meeting current regulatory requirements for electronic components in most markets.

Electrical Performance: The ISL97683IRTZ-TK delivers enhanced specifications including higher per-channel current capacity (50mA vs. 30mA), higher maximum output voltage (45V vs. 42V), and lower minimum input voltage (4V vs. 4.5V). These improvements provide design margin and expanded application flexibility.

Package Considerations: Both devices use 16-pin QFN packages with exposed pads. The SC443ULTRT uses 16-UFQFN while the ISL97683IRTZ-TK uses 16-WFQFN. Physical footprint compatibility must be verified against PCB layout specifications, as QFN variant designations may indicate dimensional differences.

Switching Frequency Difference: The ISL97683IRTZ-TK operates at 600kHz versus the SC443ULTRT's 800kHz. This lower frequency may affect EMI characteristics and component selection for external filtering networks.

Moisture Sensitivity: The SC443ULTRT carries MSL 1 (unlimited shelf life), while the ISL97683IRTZ-TK carries MSL 3 (168-hour limit). Storage and handling procedures must account for the ISL97683IRTZ-TK's moisture sensitivity requirements.

Frequently Asked Questions (FAQ)

Q: Can the ISL97683IRTZ-TK directly replace the SC443ULTRT without PCB modifications?

A: Direct replacement requires verification of package footprint compatibility. While both are 16-pin QFN devices with exposed pads, the UFQFN and WFQFN designations may indicate dimensional variations. PCB layout review is necessary before committing to a design change.

Q: What impact does the 200kHz frequency difference have on circuit design?

A: The ISL97683IRTZ-TK's lower 600kHz switching frequency affects inductor and capacitor selection for the boost converter stage. Lower frequency typically allows use of larger inductance values and may reduce high-frequency EMI, but increases component size. External component values must be recalculated based on the new switching frequency.

Q: Are there supply chain advantages to using the ISL97683IRTZ-TK?

A: Yes. The ISL97683IRTZ-TK is an active product with current manufacturing status, whereas the SC443ULTRT is obsolete. This ensures ongoing availability, stable pricing, and access to technical support from Renesas Electronics Corporation.

Q: How does the higher current rating of the ISL97683IRTZ-TK affect thermal design?

A: The ISL97683IRTZ-TK's 50mA per-channel rating versus the SC443ULTRT's 30mA increases power dissipation capability. Thermal analysis should be performed to confirm that existing thermal management (PCB copper area, heat sinking) remains adequate for the new device's power profile.

Q: What are the implications of the MSL 3 moisture sensitivity rating?

A: MSL 3 components require storage in controlled humidity environments (≤60% RH) and have a 168-hour floor life after moisture exposure. Handling procedures must include desiccant storage, and components must be baked before reflow if floor life is exceeded. This differs from the SC443ULTRT's MSL 1 unlimited shelf life.

Q: Does the ISL97683IRTZ-TK support the same PWM dimming range as the SC443ULTRT?

A: Both devices use PWM-based dimming control. Specific dimming frequency and duty cycle ranges must be verified in the respective datasheets to confirm functional equivalence for the target application.

Q: What regulatory certifications should be verified for the ISL97683IRTZ-TK in my application?

A: The ISL97683IRTZ-TK carries ROHS3 compliance and REACH unaffected status. Verify that these certifications meet your end-product regulatory requirements, which may vary by geographic market and application category.