Freescale Semiconductor MC145572FNR2

The MC145572 interfaces a two-wire ISDN U line to a digital equipment interface. Its transmit and receive paths handle 2B1Q line symbols, clock recovery and framing support. The NXP-hosted Motorola/Freescale manual covers MC145572FN pin assignments and operation; its ordering information does not independently resolve the catalog's R2 suffix.

• Integrated ISDN U-interface 2B1Q transmit and receive paths.
• Selectable NT or LT operation.
• Multiple digital interface configurations.
• Loopback modes for line and equipment diagnostics.
• 44-lead PLCC footprint documented by the manufacturer.

The device supports U-interface line coding and framing, host control and test loopbacks. The manual describes MCU and GCI selections, IDL2 operation and separate analog receive/transmit power connections. Interface pin functions are multiplexed by mode; consult the mode-specific timing tables before wiring or firmware changes.

The manufacturer manual calls MC145572FN a 44-lead PLCC. The catalog describes MC145572FNR2 as 44-LCC (J-lead), which is consistent with a leaded chip carrier but does not establish exact suffix or lead-finish details. The local package workbook maps this catalog outline to normalized 44-LCC and /upload/package/44-LCC.jpg. The JPG is absent. Verify outline, pin-one orientation and board land pattern against the controlled drawing.

Footprint checks

• Confirm 44 leads and pin one.
• Check J-lead pad and socket geometry.
• Route analog pairs and crystal per manufacturer guidance.

The registered package JPG is missing locally, so publication is blocked.

The 44-PLCC top-view diagram puts RxP/RxN on pins 5/6 and TxP/TxN on pins 9/12. RESET is pin 14, NT/LT pin 15 and IRQ pin 17. XTALout/XTALin are pins 32/33; VDD is pin 44. MCU/GCI is pin 43. Several digital pins have alternate functions, so verify the chosen interface mode and the full numbered manual table before layout.

These are family-level design facts. Recheck electrical maxima, timing and the exact R2 order suffix before use.

No unverified internal alternative is linked. Compare line coding, LT/NT configuration, digital interface, power domains, clocking, transformer network and the 44-pin footprint. A different MC145572 suffix should not be treated as interchangeable solely because it shares the FN base name.

The original Motorola/Freescale MC145572 user manual is hosted by NXP. It supplies the FN pin map, interface behavior and application guidance. The complete MC145572FNR2 suffix is shown by distributor catalog entries but was not independently established in the manufacturer manual consulted for this draft.

• Legacy ISDN U-interface network termination.
• Line-termination and subscriber-loop equipment.
• Replacement of qualified telecom control boards.
• Laboratory maintenance and loopback testing of existing systems.

Verify the exact FNR2 marking, manufacturer, date/lot code, J-lead condition, moisture handling and supply-chain traceability. An LCSC exact-code listing showed zero stock and quantity prices beginning near USD 46.50 for one piece; another aggregator showed smaller quoted stock with different tiers. These are not a confirmed current authorized quote and conflict with the catalog's stock and USD 16.69 price. No inventory or price update is made.

Validate exact FNR2 provenance, 44-pin J-lead footprint, power-domain decoupling, line transformer, clocking and digital interface mode. Missing registered package JPG and conflicting unverified current stock/price tiers prevent automatic publication.