Freescale Semiconductor MC145572FN

The MC145572 provides the physical-layer U-interface for ISDN Basic Access over a two-wire line. It can be configured for LT (line termination) or NT (network termination) and supports the 2B1Q line code specified in the manufacturer's U-interface documentation. It combines the line transceiver, timing, framing and host/data-interface functions in one IC. Configuration is through mode pins and either a serial or parallel control port.

The NXP-hosted original guide explicitly labels MC145572FN as a 44-lead PLCC and provides a top-view pin assignment. LCDChip records 44-LCC (J-Lead); its established package register maps this to 44-LCC.jpg. Treat the manufacturer's PLCC drawing as authoritative for the exact land pattern, pin numbering and J-lead geometry.

Mechanical checks

• Verify the 44-lead PLCC top view and pin-1 indicator.
• Compare socket and PCB pad geometry with the manufacturer drawing.
• Maintain line-side isolation and grounding required by the system design.

The expected catalog JPG is missing locally and returns HTTP 404 on the production site. It is not a verified footprint drawing.

These groups are visible in the manufacturer's exact MC145572FN 44-lead PLCC pin diagram. Use the full manual for all numbered pins and alternate functions.

Operating limits, line coupling, clock sources, reset sequencing and mask-set differences require the complete original manual and errata.

Another U-interface device is not automatically a drop-in replacement. Compare LT/NT modes, 2B1Q line behavior, GCI/IDL timing, control-port mapping, clocking, reset and interrupt behavior, analog line pins, 44-lead footprint and applicable mask-set errata. Maintain system-level ISDN compliance and line-side protection.

No internal alternative-product link is asserted without an exact LCDChip catalog match and engineering verification.

NXP hosts the Motorola/Freescale MC145572 documentation and marks the product no longer manufactured. The manufacturer's ISDN U-Interface Transceiver manual, revision 0, includes the exact MC145572FN 44-lead PLCC top-view assignment and detailed interface descriptions.

For this discontinued device, confirm the exact FN marking, mask set, lot traceability and electrical behavior against the NXP-hosted original manual and errata. Verify package condition and storage history. The absent catalog image does not substantiate identity or mechanical fit.

Validate line coupling, surge and isolation design, 2B1Q timing, external clocks, mode pins, power domains and reset behavior against the complete manual. Review applicable mask-set errata and the actual board revision. Restore and verify the production package JPG before publication.