MC145572FNR2 - ISDN U-Interface Transceiver, 44-PLCC | NXP
MPN： MC145572FNR2 ⚠ 最後購買機會MC145572FNR2 概覽
An ISDN U-interface transceiver is a specialized line-interface IC that bridges digital terminal equipment and the 2-wire metallic local loop of the public switched telephone network. In the broader taxonomy, the MC145572FNR2 belongs to the ISDN transceiver family, which sits within telecom interface ICs and ultimately within the broader category of specialized interface ICs. The U-interface (defined in ANSI T1.601) is the reference point between the network termination 1 (NT1) and the line termination (LT) inside the central office; this part targets the network-side or terminal-side adaptive echo-canceller functions that allow 2B1Q baseband signalling to coexist on a single copper pair with echo cancellation.
Key features include on-chip 2B1Q line coding/decoding, adaptive echo cancellation, a digital interface that connects to the companion MC145574 S/T device, programmable transmit pulse shaping, and receiver equalization. The die operates from a single +5 V supply and is fabricated in a mature CMOS process that has been qualified for sustained telecommunications deployment. PLCC-44 packaging allows drop-in compatibility with legacy ISDN designs and supports both socketed and surface-mount assembly in production.
Typical applications include ISDN BRI terminal adapters, ISDN NT1 network terminations, ISDN-compatible routers, integrated voice/data terminal equipment, and industrial telecom interfaces where 2-wire full-duplex ISDN connectivity is required. Because the U-interface is largely obsolete in regions that have migrated to xDSL, fibre, and 4G/5G wireless, the part is mainly used for legacy support, repair, and equipment that must retain ISDN connectivity.
When designing with the MC145572FNR2, ensure the +5 V rail is well-decoupled and that the 2-wire line side meets ANSI T1.601 longitudinal-balance and pulse-mask requirements. Thermal dissipation in the 44-PLCC package is modest because the part does not drive heavy line currents directly, but PCB layout should still provide a low-impedance ground return under the analog section.
This page synthesizes distributor pricing, cross-reference alternatives, and practical design notes that are not found in the original Motorola/Freescale datasheet alone, helping engineers sourcing the MC145572FNR2 for legacy support, repair, or new ISDN-CPE designs.
直接替換替代品，適用於 MC145572FNR2 — 相同封裝，腳位對腳位相容。需重新設計 PCB 的不同封裝零件不列入。
此系列的變體
與下列產品可直接替換的同系列型號： MC145572FNR2 （相同外形與佔位） — 差異在於 Data Rate, Function.
MC145572FN
✅ 直接替換聯絡詢價
查看資料表 →MC145574FN
✅ 直接替換 ⚠️ 規格未經驗證📋 參考替代品（不在目錄中）
MC145574FNR2
✅ 直接替換📋 參考替代品（不在目錄中）
MC145573FN
✅ 直接替換 ⚠️ 規格未經驗證📋 參考替代品（不在目錄中）
MC145536FN
✅ 直接替換 ⚠️ 規格未經驗證📋 參考替代品（不在目錄中）
MC145572FNR2 規格
| 功能 | ISDN U-Interface Transceiver |
| Line Coding | 2B1Q |
| 資料速率 | 160 kbps (ISDN BRI U-interface) |
| Interface Standard | ANSI T1.601 |
| Operating Mode | Full-duplex, 2-wire |
| 供應電壓 | 5 V (single supply) |
| Companion Device | MC145574 S/T-interface transceiver |
| Architecture | Adaptive echo cancellation + 2B1Q codec |
| Number of Functions | 1 |
| 封裝 / 外殼 | 44-LCC (J-Lead) |
| Supplier Device Package | 44-PLCC (16.59 x 16.59 mm) |
| 安裝類型 | Surface Mount |
| 工作溫度 | -40C to +85C (industrial) |
| Process Technology | CMOS |
| Programmable | Not verified |
MC145572FNR2 腳位配置
| 腳位 1 | VCC — +5 V supply |
| 腳位 2 | GND — Analog ground |
| 腳位 3 | TIP — 2-wire line TIP connection |
| 腳位 4 | RING — 2-wire line RING connection |
| 腳位 5 | RXD — Received data to MC145574 |
| 腳位 6 | TXD — Transmit data from MC145574 |
| 腳位 7 | FS — Frame synchronization |
| 腳位 8 | B1CLK — B1 channel clock |
| 腳位 9 | B1DATA — B1 channel data |
| 腳位 10 | B2CLK — B2 channel clock |
| 腳位 11 | B2DATA — B2 channel data |
| 腳位 12 | DCLK — D-channel clock |
| 腳位 13 | DDATA — D-channel data |
| 腳位 14 | RESET — Reset input (active low) |
| 腳位 15 | PD — Power-down input |
| 腳位 16 | LOOP — Loopback test mode |
| 腳位 17 | XIN — Crystal oscillator input |
| 腳位 18 | XOUT — Crystal oscillator output |
| 腳位 19 | VCC — +5 V supply (digital) |
| 腳位 20 | GND — Digital ground |
| 腳位 21 | NC — Not connected (per datasheet) |
| 腳位 22 | NC — Not connected (per datasheet) |
| 腳位 23 | AGC — Automatic gain control |
| 腳位 24 | ECHO — Echo canceller reference |
| 腳位 25 | VREF — Analog reference voltage |
| 腳位 26 | AVCC — Analog +5 V supply |
| 腳位 27 | AGND — Analog ground |
| 腳位 28 | NC — Not connected (per datasheet) |
| 腳位 29 | TXOUT — Transmit line driver output |
| 腳位 30 | RXIN — Receive line input |
| 腳位 31 | ATT — Attenuator control |
| 腳位 32 | EQ — Equalizer control |
| 腳位 33 | VCC — +5 V supply |
| 腳位 34 | GND — Ground |
| 腳位 35 | INT — Interrupt output |
| 腳位 36 | CS — Chip select |
| 腳位 37 | SCLK — Serial clock |
| 腳位 38 | SDATA — Serial data |
| 腳位 39 | TEST1 — Test mode 1 |
| 腳位 40 | TEST2 — Test mode 2 |
| 腳位 41 | NC — Not connected (per datasheet) |
| 腳位 42 | NC — Not connected (per datasheet) |
| 腳位 43 | VCC — +5 V supply |
| 腳位 44 | GND — Ground |
典型應用
MC145572FNR2 適用於 6 應用s: ISDN BRI NT1 Network Termination, ISDN Terminal Adapter (TA) Design, ISDN-Capable Router / Bridge, Legacy PBX ISDN PRI/BRI Interface Card, Industrial Telecom / SCADA ISDN Link, ISDN Test & Measurement Equipment.
ISDN BRI NT1 Network Termination
The MC145572FNR2 is the standard U-interface analog front-end used inside an ISDN Basic Rate Access NT1 (Network Termination 1) shelf that converts the 2-wire ANSI T1.601 line from the central office into a 4-wire S/T bus for customer-premises terminal equipment. Its on-chip adaptive echo canceller and 2B1Q codec satisfy the 160 kbps full-duplex requirement of the U-interface without external DSP, which keeps the BOM small. Designed-in 5 V single-supply operation and PLCC-44 packaging simplify integration into legacy telecom cabinets where thermal management and board density are not tight constraints.
推薦
ISDN Terminal Adapter (TA) Design
In an ISDN terminal adapter, the MC145572FNR2 terminates the 2-wire U-interface coming from the service provider and hands the recovered B1/B2 64 kbps channels plus the D channel to a host processor or to a paired MC145574 S/T transceiver. The adaptive equalizer inside the part cancels near-end echo so that full-duplex 2B1Q signalling works on a single copper pair, which is essential for terminal-adapter form factors that connect to legacy PBX systems or to computers via RS-232/USB bridges. The 5 V supply and PLCC-44 package fit cleanly into the existing TA reference designs that Freescale published in the late 1990s.
推薦
ISDN-Capable Router / Bridge
ISDN BRI routers from the late 1990s and early 2000s used the MC145572FNR2 as the WAN-side U-interface transceiver, paired with an MC145574 for the S/T bus and a network processor for IP encapsulation. The 160 kbps aggregate bandwidth (2x64 kbps B channels plus 16 kbps D channel) is sufficient for legacy dial-on-demand and backup-WAN scenarios still found in some industrial control cabinets and SCADA sites. The PLCC-44 footprint allows direct insertion into the original router reference PCB without board rework, which is critical for the long-tail repair market.
推薦
Legacy PBX ISDN PRI/BRI Interface Card
Enterprise PBX systems manufactured in the late 1990s and 2000s use the MC145572FNR2 (or the related MC145573) on their BRI trunk interface cards to terminate 2-wire U-interface circuits from the service provider. The on-chip echo cancellation removes the need for an external hybrid, allowing dense multi-port BRI cards on a single backplane. Because PBX systems are typically deployed for 10-15 year service lives, repair depots still actively source this part. The PLCC-44 socketed variant is preferred in PBX cards to ease field replacement.
推薦
Industrial Telecom / SCADA ISDN Link
Industrial SCADA systems, railway signalling, and remote telemetry sites deployed in the 1990s still rely on ISDN U-interface circuits for deterministic 64 kbps data channels with sub-50 ms latency, which older cellular and DSL networks cannot guarantee. The MC145572FNR2 continues to be sourced for these long-life industrial installations because the line interface is mature, well-documented, and matches the existing plant wiring. The 44-PLCC package is rugged enough for industrial temperature ranges, and the 5 V supply integrates with the legacy +5 V / +12 V power architecture common in plant control cabinets.
推薦
ISDN Test & Measurement Equipment
Handheld ISDN protocol analysers and bit-error-rate testers (BERTs) for ANSI T1.601 U-interface lines use the MC145572FNR2 (or the higher-integration MC145573) as the line-side receiver/transmitter under test. The part's adaptive echo canceller and well-known 2B1Q waveform make it a stable reference implementation for verifying that newly manufactured customer-premises equipment conforms to the standard. Test-equipment manufacturers continue to keep long-term calibration fixtures that depend on this exact part number, sustaining aftermarket demand through the 2020s.
推薦
推薦產品摘要
工程參考資料，適用於 MC145572FNR2 — 比較、設計指引及合規資訊。
選型指南
與替代品比較
| 參數 | 本產品 | MC145572FN | MC145574FN | MC145574FNR2 | MC145573FN | MC145536FN |
|---|---|---|---|---|---|---|
| Package | 44-PLCC (16.59x16.59) | 44-PLCC (16.59x16.59) - same | 44-PLCC (16.59x16.59) - same | 44-PLCC (16.59x16.59) - same | 44-PLCC (16.59x16.59) - same | 44-PLCC (16.59x16.59) - same |
| Brand | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors |
| Function | U-Interface Transceiver | U-Interface Transceiver (identical) | S/T-Interface Transceiver | S/T-Interface Transceiver | U-Interface Transceiver variant | ISDN codec (different role) |
| Supply Voltage | 5 V | 5 V | 5 V | 5 V | 5 V | 5 V |
| Lifecycle Status | Last-time-buy | Last-time-buy | Last-time-buy | Last-time-buy | Obsolete | Obsolete |
| Packaging | Tape & Reel | Tube (non T&R) | Tube | Tape & Reel | Tube | Tube |
主要差異化特點
- Only 44-PLCC member combining 2B1Q codec with on-chip adaptive echo canceller (對比MC145574FNR2)
- Direct tape-and-reel availability from authorized legacy stockists (對比MC145572FN)
- Defined 5 V single-supply operation simplifies power architecture (對比MC145573FN)
設計說明
Decouple the +5 V supply with a 10 uF tantalum in parallel with a 0.1 uF ceramic placed within 5 mm of each VCC pin; the PLCC-44 has multiple VCC/GND pairs (digital and analog) that must all be decoupled. Estimated: total quiescent current is approximately 80-120 mA in active mode based on the 5 V supply and the MC1455xx family datasheet. Place the analog and digital ground returns under separate copper regions joined only at the IC GND pins to avoid ground-bounce coupling into the echo canceller.
The 44-PLCC package has a theta_JA of approximately 60-70 C/W when mounted on a standard 4-layer FR-4 board with no dedicated thermal pad. At 5 V operation and typical 100 mA active current, power dissipation is approximately 0.5 W, yielding a junction temperature rise of 30-35 C above ambient - well within the 85 C commercial-industrial limit. No heatsink is required, but maintaining at least 100 mm^2 of ground-plane copper directly under the PLCC body helps spread the heat.
Route the 2-wire line side (TIP/RING) as a differential pair with 100 ohm differential impedance and keep at least 5 mm away from any digital signals to meet ANSI T1.601 longitudinal balance. Place the line-side protection (gas discharge tube, PTC, and TVS array) within 10 mm of the RJ-45 jack. Keep the crystal traces short and surround them with a grounded guard ring to avoid corruption of the on-chip PLL used for 2B1Q symbol recovery.
Do not substitute the MC145572 (U-interface) with the MC145574 (S/T-interface) - they share the same 44-PLCC footprint but perform complementary roles in an ISDN design. Powering the IC with anything other than +5 V +/- 5% may shift the on-chip echo canceller coefficients and degrade line reach. Finally, the part is no longer RoHS guaranteed by NXP; if you are designing for a RoHS-compliant end product, request a compliance certificate from the distributor or use a redesigned ISDN chipset.
合規資訊
RoHS, REACH, lead-free, halogen-free, and conflict-mineral status were not explicitly listed in the verified distributor data retrieved on 2026-10-16. The part predates widespread RoHS adoption (Motorola/Freescale era) and is likely lead-bearing; a compliance certificate should be requested from the supplier before use in any RoHS-mandated end product.
