QT60645-AS Equivalent & Substitute Parts

Part Overview

The QT60645-AS is a capacitive touch sensor IC from Microchip Technology's QMatrix™ series, designed for matrix touch button applications with up to 64 input channels. This 44-TQFP surface mount device operates via SPI interface and is classified as obsolete. Due to its discontinued status, identifying functionally compatible alternatives is essential for ongoing design support, production continuity, and system maintenance.

Substiute Parts

QT60645-AS

Microchip TechnologyIn Stock: 1054QT60645-AS Datasheet

Current PartRFQ

QT60326-ASG

Microchip TechnologyIn Stock: 2823QT60326-ASG Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

The QT60326-ASG is identified as a manufacturer-recommended substitute for the QT60645-AS. Substitution eligibility is determined by the following critical parameters:

Substitution Criteria:

• Identical package type (44-TQFP surface mount)
• Compatible voltage supply range (4.75V ~ 5.25V)
• Matching interface protocol (SPI capable)
• Equivalent operating temperature range (-40°C ~ 105°C)
• Same series family (QMatrix™)

The QT60326-ASG meets all primary substitution requirements while offering reduced input channel capacity (32 channels versus 64 channels) and enhanced resolution (9-bit versus 8-bit). The substitute part is currently in active production status with improved RoHS3 compliance.

Parameter Comparison

Engineering Selection Recommendations

For Active Production Systems: The QT60326-ASG is the appropriate substitute when the QT60645-AS reaches end-of-life. Both devices share identical electrical operating parameters (supply voltage, temperature range, package footprint) and are from the same QMatrix™ series, ensuring firmware and hardware compatibility at the interface level.

Compliance Considerations: The QT60326-ASG provides ROHS3 compliance, addressing regulatory requirements that may not be met by the non-compliant QT60645-AS. This is particularly relevant for new designs or systems requiring updated environmental compliance certifications.

Design Constraints: Applications requiring exactly 64 input channels must evaluate whether the 32-channel capacity of the QT60326-ASG is sufficient. If full 64-channel functionality is mandatory, alternative solutions outside the QMatrix™ series may be necessary. The increased supply current (25mA versus 15mA) must be verified against power supply specifications.

Frequently Asked Questions (FAQ)

Q: Can the QT60326-ASG directly replace the QT60645-AS in existing PCB layouts? A: Yes. Both devices use the 44-TQFP package with identical footprints and pin assignments compatible with SPI communication. No PCB redesign is required for package compatibility.

Q: What is the primary functional difference between these parts? A: The QT60645-AS supports up to 64 input channels with 8-bit resolution, while the QT60326-ASG supports up to 32 input channels with 9-bit resolution. Channel count reduction is the primary design trade-off.

Q: Are there firmware or software modifications needed for substitution? A: Both devices operate via SPI interface within the QMatrix™ series. Firmware compatibility depends on application-specific implementation. Consult Microchip Technology documentation for device-specific register definitions and command protocols.

Q: Does the increased supply current of the QT60326-ASG affect system design? A: The substitute requires 25mA maximum versus 15mA for the original part. Power supply capacity and current delivery specifications must be verified to accommodate this 10mA increase.

Q: Is the QT60326-ASG suitable for new designs? A: Yes. The QT60326-ASG is in active production status with ROHS3 compliance, making it appropriate for new product development and long-term supply chain planning.

Q: What is the significance of the MSL 3 rating for both parts? A: MSL 3 indicates a moisture sensitivity level requiring storage at controlled humidity (≤60% RH) with a floor life of 168 hours after moisture exposure. Both parts have identical handling requirements.