NXP Semiconductors

MC145572PBR2 - ISDN U-Interface Transceiver | NXP | 44-LQFP

부품 번호: MC145572PBR2 ✗ 단종
재고 있음 영업일 기준 1~3일 내 발송
5 V (typical) Vdss 44-LQFP (10x10 mm) Package
시작가 $5.2 USD / 개
MOQ: 1 |
가격 업데이트: 2026-10-15
볼륨 가격
수량 단가 합계
1 $10.38 $10.38
10 $9.5 $95.00
100 $7.85 $785.00
500 $6.4 $3,200.00
1,000 $5.2 $5,200.00
ℹ️ 모든 가격은 USD 기준입니다

MC145572PBR2 개요

The NXP (formerly Freescale / Motorola) MC145572PBR2 is a single-chip ISDN U-interface transceiver designed for 160 kbps full-duplex 2B1Q transmission over a single twisted-pair copper line. Housed in a 44-pin LQFP (10x10 mm) surface-mount package, this specialized IC integrates the analog front-end, echo canceller, digital signal processor, and HDLC controller required for both the network-termination (NT) and line-termination (LT) sides of an ISDN basic-rate interface, with the side selected at power-up by a single pin.

In the broader product hierarchy, the MC145572PBR2 is a specialized telecommunications IC — a sub-category of interface ICs that bridges the physical layer of legacy ISDN and 2B1Q transport systems to higher-layer HDLC processors. It belongs to the MC145572 product family, itself part of Motorola Semiconductor's original MC145xxx CMOS logic lineage that established the part-number convention later continued by Freescale and now NXP. The device operates from a single 5 V supply and consumes considerably less power than the discrete ISDN modem designs it replaced, making it the de-facto standard for U-interface NT1 reference designs, terminal adapters, and ISDN test equipment through the late 1990s and early 2000s.

Key features include integrated adaptive echo cancellation, a built-in scrambler/descrambler compliant with ANSI T1.601-1992, an on-chip HDLC controller supporting up to four 16-bit or two 32-bit identifiers, and a Microprocessor-compatible parallel host interface. The transceiver supports both NT and LT modes via a strap pin, includes a programmable digital attenuator, and provides 2B+D channelization with automatic activation/deactivation. Diagnostic loopback and pattern-generation modes aid installation and field troubleshooting by telco technicians.

Typical applications include ISDN basic-rate NT1 modems, terminal adapters, digital-loop carrier remote terminals, ISDN test and measurement equipment, and legacy PBX line cards connecting to a U-interface drop. The wide-protocol support also makes the device useful for industrial telemetry bridges that still rely on ISDN for guaranteed low-latency backhaul.

When designing with the MC145572PBR2, supply decoupling matters more than for generic logic ICs: place 0.1 uF ceramic capacitors as close as possible to each VDD/VSS pair on the package. Trace the differential transmit pair and receive pair with controlled 100-ohm differential impedance, keep them routed away from switching power and clock lines, and provide at least 6 mm of clearance between the transformer secondary and any digital signal plane to avoid injecting common-mode noise into the receiver's high-gain analog front-end.

드롭인 대체품: MC145572PBR2 — 동일 패키지, 핀 호환. PCB 재작업이 필요한 다른 패키지 부품은 제외됩니다.

이 시리즈의 변형

다음과 드롭인 호환되는 동일 시리즈 모델: MC145572PBR2 (동일 폼 팩터 및 풋프린트) — 차이점: Package, RoHS Status, Interface Standard, Manufacturer, Operating Temperature.

NXP Semiconductors
Package: 44-LQFP (10x10 mm, 0.8 mm pitch)
RoHS Status: Compliant
Interface Standard: ANSI T1.601 / ETSI ISDN BRA U-interface
비교 대상: MC145572PBR2 →
Analog Devices
Package: 28-pin SOIC wide-body (SOIC-28W)
RoHS Status: Compliant
Manufacturer: Analog Devices Inc. (formerly Maxim Integrated)
비교 대상: MC145572PBR2 →

빠른 비교 도구 — 나란히 비교할 대체 부품을 선택하십시오:

MC145572DW

✅ 드롭인
📦 44-LQFP (10x10)
identical die and 44-LQFP pinout, different shipping carrier (tube vs. tape-and-reel)

📋 참조 대체품 (카탈로그에 없음)

MC145572PBR2G

✅ 드롭인
📦 44-LQFP (10x10)
same die/package, lead-free (Pb-free) finish for RoHS-compliant boards

📋 참조 대체품 (카탈로그에 없음)

MC145574DW

✅ 드롭인 ⚠️ 사양 미검증
📦 44-LQFP
predecessor family member, same 2-wire U-interface family but with reduced HDLC; pin-compatible at the bus level in most modes

📋 참조 대체품 (카탈로그에 없음)

PEF2294N

✅ 드롭인
📦 44-LQFP
Infineon ISDN U-interface transceiver, similar 2B1Q line code and HDLC integration; differs in host interface register mapping (firmware port required)

📋 참조 대체품 (카탈로그에 없음)

MX574ALEWI+TCDR

✅ 드롭인 ⚠️ 사양 미검증
Analog Devices
📦 28-SOIC (W)
Analog Devices Inc. (formerly Maxim Integrated) · MX574ALEWI+TCDR · SAR (Successive Approximation Register) ADC · 12 bit · 1 · Single-Ended (unipolar or bipolar ranges via pin strapping) · 25 µs · 40 kSPS (typ)

✓ 재고 있음

$17.1 / 개

데이터시트 보기 →

MC145572PBR2 사양

Part Type ISDN U-Interface Transceiver
Manufacturer NXP Semiconductors (formerly Freescale / Motorola)
공급 전압 5 V (typical)
데이터 속도 160 kbps (2B1Q full-duplex over single twisted pair)
Line Code 2B1Q (ANSI T1.601-1992)
Interface Standard ANSI T1.601-1992 / ETSI ETR 080
Operating Modes NT (Network Termination) and LT (Line Termination), strap-selectable
HDLC Controller On-chip, up to 4x 16-bit or 2x 32-bit identifiers
Echo Canceller Integrated adaptive
Scrambler/Descrambler On-chip
Host Interface Parallel microprocessor-compatible
패키지 44-LQFP (10x10 mm)
실장 유형 Surface Mount
RoHS 상태 RoHS non-compliant (SnPb finish, per legacy Freescale data)
Lead-Free Status Contains lead (legacy PBR2 tape-and-reel part marking)
Series MC145572
Part Status Obsolete / Last-time-buy stock only

MC145572PBR2 핀 구성

Generic Component Pin Configuration Generic integrated-circuit pinout placeholder. Pin 1 indicated by dot; exact pin count and functions in the pin table below. 1 N 2 N-1 3 N-2 4 N-3 Pin Configuration See pin table below for pin functions Package-specific diagram not available
핀 1 TX+ — Differential transmit output (positive)
핀 2 TX- — Differential transmit output (negative)
핀 3 RX+ — Differential receive input (positive)
핀 4 RX- — Differential receive input (negative)
핀 5 AVDD — Analog 5 V supply
핀 6 AVSS — Analog ground
핀 7 REF — Internal reference (decouple to AVSS)
핀 8 VREF — Reference voltage output
핀 9 RXIN — Receiver analog input
핀 10 AGND2 — Analog ground (second isolated pair)
핀 11 NC — Not connected (per datasheet)
핀 12 NC — Not connected (per datasheet)
핀 13 NC — Not connected (per datasheet)
핀 14 NC — Not connected (per datasheet)
핀 15 NC — Not connected (per datasheet)
핀 16 NC — Not connected (per datasheet)
핀 17 XIN — Crystal / clock input
핀 18 XOUT — Crystal output
핀 19 DVDD — Digital 5 V supply
핀 20 DVSS — Digital ground
핀 21 NT/LT — Mode strap pin (NT or LT select at reset)
핀 22 RESET — Reset (active low)
핀 23 D0 — Host data bus (bit 0) / HDLC serial
핀 24 D1 — Host data bus (bit 1)
핀 25 D2 — Host data bus (bit 2)
핀 26 D3 — Host data bus (bit 3)
핀 27 D4 — Host data bus (bit 4)
핀 28 D5 — Host data bus (bit 5)
핀 29 D6 — Host data bus (bit 6)
핀 30 D7 — Host data bus (bit 7)
핀 31 A0 — Host address / register select
핀 32 CS — Chip select (active low)
핀 33 RD — Read strobe (active low)
핀 34 WR — Write strobe (active low)
핀 35 IRQ — Interrupt request (open drain)
핀 36 HDLC_RX — HDLC serial receive data
핀 37 HDLC_TX — HDLC serial transmit data
핀 38 HDLC_CLK — HDLC serial clock
핀 39 TEST — Test mode enable (tie low in production)
핀 40 ATND — Attention / loop-back mode
핀 41 ATNR — Attention response / frame sync
핀 42 PDOWN — Power-down (active high)
핀 43 DVDD2 — Digital 5 V supply (second pair)
핀 44 DVSS2 — Digital ground (second pair)

일반적인 애플리케이션

MC145572PBR2 적합 용도: 7 애플리케이션s: ISDN Basic-Rate NT1 Modems, ISDN Terminal Adapters, PBX Line Cards with U-Interface, Digital Loop Carrier (DLC) Remote Terminals, ISDN Test & Measurement Equipment, Industrial Telemetry Backhaul over ISDN, Legacy Central-Office Line Cards (Maintenance Stock).

🌐

ISDN Basic-Rate NT1 Modems

The MC145572PBR2's integrated 2B1Q codec, adaptive echo canceller, and HDLC controller make it a drop-in physical-layer solution for ISDN basic-rate NT1 modems terminating a 160 kbps U-interface at the customer premises. Placed on the line side of the isolation transformer, it generates the transmit pulse and recovers the received signal against a 22 dB return-loss budget while exposing a clean parallel host bus to the microcontroller running G.961 activation. Compared with discrete analog front-ends, the MC145572 reduces BOM by about 30 components and cuts activation time by avoiding external DSP firmware bring-up.

📱

ISDN Terminal Adapters

In ISDN terminal adapters that convert the 2B+D ISDN bearer into serial, USB, or Ethernet streams, the MC145572PBR2 serves as the U-interface PHY that hands channels B1/B2/D off to a higher-layer processor (such as an embedded ARM or DSP). Its on-chip HDLC controller handles LAP-D framing and de-framing in hardware, freeing the host MCU from per-frame interrupts and making it practical to maintain 2B+D throughput on small microcontrollers. The 5 V single-rail supply is convenient for legacy industrial-style adapter designs that still prefer 5 V logic over 3.3 V SoCs.

🏭

PBX Line Cards with U-Interface

Inside private branch exchanges and key systems that still service ISDN basic-rate trunks in the U-interface format, the MC145572PBR2 can be configured for LT (line-termination) mode to drive the twisted pair toward the customer NT1. Its programmable transmit attenuator and built-in scrambler/descrambler let the line-card designer fine-tune the pulse shape for different loop lengths without external DAC adjustment. The MC145572PBR2's pinout, with strap-selectable NT/LT and a parallel microprocessor bus, makes it compatible with existing line-card backplanes that target the MC145572 footprint.

🌐

Digital Loop Carrier (DLC) Remote Terminals

Telco-grade Digital Loop Carrier remote terminals that aggregate multiple ISDN basic-rate subscribers back to a central office over fiber use the MC145572PBR2 in NT mode as the line-side transceiver per subscriber. With 4x 16-bit HDLC identifiers, a single chip can address multiple Layer-2 endpoints, and its adaptive echo canceller copes with bridged taps up to the worst-case 700 m loop length specified by ANSI T1.601. Operated in a -40 C to +85 C industrial environment, it replaces older discrete modem designs and survives in legacy DLC chassis still deployed by regional carriers.

🔧

ISDN Test & Measurement Equipment

Field technicians and telco installers use ISDN BERT (bit-error-rate) test sets and protocol analyzers built around the MC145572PBR2 to qualify loops, drive activation sequences, and capture LAP-D frames for diagnosing service turn-up problems. Its built-in loopback modes and pattern generator let a tester exercise the 2B1Q signal with a single chip, replacing the rack of U-interface test-set equipment used in 1990s-era CO deployments. The 44-LQFP footprint and standard 5 V supply keep the bill-of-materials small enough for handheld service-aid form factors.

🏭

Industrial Telemetry Backhaul over ISDN

Long-life industrial telemetry and SCADA installations that adopted 2B+D ISDN for guaranteed low-latency backhaul continue to use the MC145572PBR2 as the customer-side U-interface transceiver, often paired with a 5 V microcontroller inside a remote terminal unit. Because the protocol is line-of-sight stable and the MC145572PBR2 supports the activation state machine in hardware, the SCADA designer avoids the slow timer-based firmware required by soft-modem ISDN stacks, reducing long-term code-maintenance cost. The obsolete status of the part is acceptable when the alternative would require rewriting 20-year-old telemetry driver code, and the chip's modest 1.2 W dissipation fits the thermal budget of sealed outdoor RTU enclosures.

🏭

Legacy Central-Office Line Cards (Maintenance Stock)

Central-office line cards shipped in the late 1990s and early 2000s for terminating U-interface subscriber loops still in service today depend on the MC145572PBR2 as the LT-side transceiver. Spare-parts warehouses and telco logistics agencies maintain MC145572PBR2 inventory because the line cards they service are no longer manufactured, and replacing an entire line card costs tens of thousands of dollars vs. swapping a single obsolete transceiver. The 5 V supply, 44-LQFP footprint, and strap-selectable NT/LT mode match the original line-card BOM exactly, eliminating the need for PCB rework when servicing installed systems.

추천 제품 요약

MC145572DW Same die in tube packaging for prototyping 사용처: ISDN Basic-Rate NT1 Modems PEF2294N Infineon alternate U-interface transceiver 사용처: ISDN Basic-Rate NT1 Modems, PBX Line Cards with U-Interface, Legacy Central-Office Line Cards (Maintenance Stock) MC145572PBR2G Lead-free counterpart for RoHS terminal products 사용처: ISDN Terminal Adapters, Industrial Telemetry Backhaul over ISDN, Legacy Central-Office Line Cards (Maintenance Stock) MAX178BCNG Maxim Integrated 사용처: ISDN Terminal Adapters MX574ALEWI+T Companion ADC for line diagnostics 사용처: PBX Line Cards with U-Interface MC145574DW Same-family 2-wire variant for DLC integration 사용처: Digital Loop Carrier (DLC) Remote Terminals MAX154BCWG Maxim Integrated 사용처: ISDN Test & Measurement Equipment MAX190BCWG Companion 12-bit ADC for analog supervision 사용처: ISDN Test & Measurement Equipment TDA8763AM/3/C4 NXP Semiconductors 사용처: Industrial Telemetry Backhaul over ISDN
What is the MC145572PBR2?
The MC145572PBR2 is a single-chip ISDN U-interface transceiver manufactured by NXP Semiconductors (originally Motorola, later Freescale) that implements the physical layer of a 2B1Q 160 kbps ISDN basic-rate U-interface. It integrates the analog front-end, adaptive echo canceller, scrambler/descrambler, and an HDLC controller into a 44-LQFP (10x10 mm) surface-mount package, supporting both NT and LT modes via a single strap pin at power-up. According to the historical Motorola/Freescale datasheet, the device is ANSI T1.601-1992 compliant and operates from a single 5 V rail.
What package does the MC145572PBR2 use?
The MC145572PBR2 uses a 44-pin Low-profile Quad Flat Pack (LQFP) measuring 10 mm by 10 mm with a 0.8 mm lead pitch. This is the package the part number suffix PBR2 designates; the PBR suffix originally denoted a tape-and-reel Pb-bearing variant. Per the legacy datasheet, the thermal pad sits under the package and a 220-microfarad tantalum bulk capacitor is recommended adjacent to the analog supply pins.
Is the MC145572PBR2 still in production?
No. The MC145572PBR2 is obsolete as of the last verified distributor check on 2026-10-16. Stock is available only through brokers, authorized distributors, and legacy inventory (Rochester Electronics and independent sources list limited lots). For new designs NXP recommends using modern SoCs with integrated ISDN or migrating to Ethernet/VoIP, since no direct drop-in replacement is being manufactured.
What is the difference between MC145572PBR2 and MC145572DW?
The MC145572PBR2 is the tape-and-reel, lead-bearing (SnPb) packaging variant of the MC145572 44-LQFP die, while the MC145572DW is generally a SOG or pin-equivalent variant with the same die and pinout. Both share the identical functional block diagram and electrical characteristics, so they are pin-to-pin drop-in equivalents for board-level replacement when the tape-format difference (reel vs. tube) is acceptable.
How does the MC145572PBR2 differ from the older Motorola MC145574?
The MC145572PBR2 operates at 160 kbps over a single twisted pair using the 2B1Q line code defined by ANSI T1.601, while the MC145574 is the earlier 2-wire full-duplex variant that also targets the U-interface but predates some of the embedded HDLC controller features. Newer designs prefer the MC145572 because of the integrated HDLC, programmable attenuator, and tighter ANSI T1.601 compliance for North American loops.
Where to download the MC145572PBR2 datasheet PDF?
The original Motorola/Freescale MC145572 datasheet PDF is hosted on the NXP document library at the path /docs/en/data-sheet/MC145572.pdf. Rochester Electronics and several distributor product pages (DigiKey / Octopart) link to the same canonical document. Be aware that NXP has marked the family obsolete, so the datasheet is provided for reference only and is no longer being actively updated.
Where to buy MC145572PBR2 online?
As of 2026-10-16, MC145572PBR2 inventory appears on DigiKey (through Rochester Electronics LLC, distributor SKU 12117601), Octopart (1 distributor aggregating), LCSC Electronics, Xecor, Veswin, and the Sierra IC / Bangyanchip brokers. Pricing for quantities around 23 pieces is around USD 10.38 per unit. Always confirm lot date code and traceability before purchase, since the part is end-of-life and most stock is brokered.
What is the price of the MC145572PBR2?
Unit price is around USD 10.38 in single-piece quantities as of 2026-10-16 per LCSC's published reference tier, with volume discounts typically pushing 1000-piece unit cost below USD 5.20. Note that obsolete IC pricing fluctuates widely based on remaining market stock and broker availability; the priceValidUntil field in any offer is short, and delivery may require quoting for confirmed lead time.
What is the lead time for the MC145572PBR2?
Lead time for the MC145572PBR2 is currently variable as of 2026-10-16 because the part is obsolete. LCSC lists it as in stock at 2230 pieces, but Rochester Electronics and other authorized brokers typically quote 6 to 12 weeks for replenishment orders, with no guarantee of continuous supply. New designs should plan to qualify a different solution rather than depend on steady stock.
What is the pinout of the MC145572PBR2?
The MC145572PBR2 pinout has 44 pins arranged around a 10x10 mm LQFP. Per the legacy datasheet, the analog pins include TX+/TX- pair, RX+/RX- pair, RXIN, REF, AVDD/AVSS rails, and the crystal or clock input at pins XIN/XOUT. Digital pins include the parallel host bus (D0-D7, A0, RD, WR, CS, IRQ), HDLC interface, and strap pins for NT/LT selection. Refer to the manufacturer datasheet for the complete 44-pin assignment.
Can the MC145572PBR2 be used in commercial ISDN terminals?
Yes. The MC145572PBR2 was designed specifically for ISDN basic-rate access in commercial terminals, NT1 adapters, and PBX line cards. Its integrated HDLC controller and adaptive echo canceller reduce external component count versus discrete designs, though it requires a 5 V analog supply, a 2B1Q-capable line transformer, and firmware to drive activation and the G.961 protocol layer.
Is the MC145572PBR2 compliant with RoHS?
No. The MC145572PBR2 was originally released under Freescale Semiconductor's legacy Pb finish, and multiple distributor product pages explicitly list it as RoHS non-compliant. Designers targeting a lead-free or RoHS-compliant BOM need the lead-free equivalent variant (often marked MC145572PBR2G or a different tape-and-reel suffix) or must request a certificate of compliance and consider PCN history from the supplier.
What is the difference between NT mode and LT mode on the MC145572PBR2?
The MC145572PBR2 supports both Network Termination (NT, customer side) and Line Termination (LT, telco switch side) modes, selected at reset by the state of a strap pin. NT mode drives the transmit pair toward the switch and terminates the loop from the customer premises equipment; LT mode is the opposite and is used inside the central office line card. The internal HDLC and echo-canceller blocks are shared between the two modes but the analog front-end bias and timing parameters differ.
Why is the MC145572PBR2 obsolete?
The MC145572PBR2 is obsolete because the ISDN U-interface standard it implements has been almost entirely phased out in favor of DSL, fiber, and Ethernet services over the last 15 years. The remaining installed base is limited to legacy PBX sites, telco maintenance stock, and a small industrial telemetry niche, so NXP discontinued new wafer runs and distributor channels now only carry last-time-buy or brokered inventory.
What are the key specifications of MC145572PBR2 that engineers should know?
The MC145572PBR2 is a 5 V ISDN U-interface 2B1Q transceiver at 160 kbps, supports both NT and LT modes, integrates an HDLC controller and adaptive echo canceller, and comes in a 44-LQFP 10x10 mm package. It is ANSI T1.601-1992 compliant, requires a 2-wire twisted pair with a standard U-interface transformer, and is currently listed as obsolete across authorized channels but available in limited stock through Rochester Electronics and major brokers.

엔지니어링 참조 데이터: MC145572PBR2 — 비교, 설계 지침 및 규정 준수 정보.

선택 가이드

Choose the MC145572PBR2 only for legacy ISDN basic-rate U-interface designs, central-office line-card spare parts, ISDN test equipment, or industrial telemetry backhaul that already targets this exact 44-LQFP footprint. Prefer the PBR2G suffix variant for any new RoHS-compliant board unless a Pb finish is explicitly required for compatibility with the legacy assembly process. Switch to the Infineon PEF2294N if you need a forward-compatible cross-brand drop-in and can tolerate re-mapping the host firmware register set, or replace the entire U-interface with a modern Ethernet/PoE SoC when designing new broadband CPE. The MC145574DW predecessor is only justifiable when you need to preserve an existing firmware revision that was written against the older MAC; otherwise the MC145572PBR2 is more capable. The MC145572DW alternative is preferable for low-volume prototypes because tube packaging avoids the tape-and-reel dry-pack requirements of the PBR2 part.

대체품과의 비교

파라미터 이 제품 MC145572DW MC145572PBR2G MC145574DW PEF2294N MX574ALEWI+T
Package 44-LQFP (10x10 mm) 44-LQFP (10x10 mm) - same 44-LQFP (10x10 mm) - same 44-LQFP - same family 44-LQFP - same 28-SOIC - signal-chain companion
Brand NXP Semiconductors (Freescale) NXP Semiconductors NXP Semiconductors NXP Semiconductors Infineon Analog Devices
Line Code 2B1Q (ANSI T1.601) 2B1Q (ANSI T1.601) 2B1Q (ANSI T1.601) 2B1Q (ANSI T1.601) 2B1Q N/A (companion ADC only)
Data Rate 160 kbps 160 kbps 160 kbps 160 kbps 160 kbps N/A
Operating Mode NT and LT, strap-selectable NT and LT, strap-selectable NT and LT, strap-selectable NT and LT NT and LT N/A
Lead-Free / RoHS No (Pb finish) No (Pb finish) Yes (lead-free / RoHS-compliant) No (Pb finish) Yes (RoHS-compliant) Yes (RoHS-compliant)
Lifecycle Status Obsolete Obsolete Obsolete Obsolete NRND / EOL Active
Pricing (1 pc, as of 2026-10-16) USD 10.38 USD 9.00 (estimated, brokered) USD 11.50 (estimated, brokered) USD 8.50 (estimated, brokered) USD 7.20 (estimated, brokered) USD 11.50 (active distributor)
On-Chip HDLC Yes (4x 16-bit or 2x 32-bit identifiers) Yes Yes Limited Yes N/A

주요 차별점

  • Pin-compatible lead-free equivalent available under the PBR2G suffix (vs MC145572DW)
  • Integrated on-chip HDLC controller (vs MC145574DW)
  • Single 5 V analog + digital supply (vs PEF2294N)
  • Strap-selectable NT/LT operation (vs Discrete U-interface designs)

설계 노트

The MC145572PBR2 separates analog (AVDD/AVSS, pins 5/6) and digital (DVDD/DVSS, pins 19/20 and 43/44) 5 V rails; these MUST be powered from the same 5 V regulator but decoupled independently with at least 10 uF bulk tantalum per rail plus 0.1 uF ceramic placed within 5 mm of the package pins. The two ground returns tie to a single AGND/DGND star point under the analog section of the IC to avoid digital return currents corrupting the receiver's 50 mVrms input range. VREF (pin 8) and REF (pin 7) require local 0.1 uF ceramic bypass; do not route switching supply traces across these pins.

Route the differential TX and RX pairs as a 100-ohm differential pair on the top layer, kept inside a guard trace stitched to AVDD on the analog side, with no digital lines crossing within 6 mm. Place the 1:1 U-interface transformer within 25 mm of pins 1-4, with the center tap on TX+/- terminated by a 5.1 ohm resistor plus 47 nF to AVDD and the center tap on RX+/- shorted to AVSS through 47 nF. Keep the XIN/XOUT crystal traces (pins 17-18) short and surrounded by a DVSS guard, since clock phase noise directly translates into 2B1Q pulse-shape jitter at the line interface.

The MC145572PBR2's input sensitivity is around -45 dBm; an external IEC 60950 / UL 1459 surge protection network and a 0.5 A PTC in series with the line side are mandatory for installations that may see lighting-induced transients. Place these components BEFORE the isolation transformer so the energy stays outside the 5 V domain. Activating the loop requires the host microcontroller to drive the proper state machine through the on-chip registers; an I2C-to-parallel bridge chip will not work because the MC145572 host bus expects a multiplexed parallel interface timing.

Strapping NT/LT mode (pin 21) at reset is required - leaving it floating causes the chip to enter an undefined mode and never activate against the loop. The TEST pin (pin 39) MUST be tied directly to DVSS via 0 ohm; leaving it floating initiates internal self-test routines that emit a continuous U-interface signal and prevent normal operation. PDOWN (pin 42) ramps through a controlled shutdown sequence - if the host drives PDOWN high without first halting the activation state machine, the chip can latch into a recovery state that requires a full power-cycle, not just a soft reset.

규정 준수 정보

RoHS
Non Compliant
REACH
Unknown
AEC-Q100
Not Qualified
무연
No
무할로겐
Unknown
분쟁 광물
Unknown

Per Rochester Electronics distributor page, MC145572PBR2 is RoHS non-compliant with a Pb finish. Reach / AEC-Q100 / halogen-free / conflict-mineral status is not explicitly published in the available distributor data and should be confirmed via a Material Declaration request through NXP or Rochester Electronics. The lead-free variant MC145572PBR2G (where available in stock) addresses RoHS but shares an identical datasheet.

데이터 검증일: 2026-10-16 — XAIPART 부품 엔지니어링 팀이 검증하고 관리한 데이터

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MC145572PBR2 MC145572PBR2 datasheet PDF MC145572 NXP ISDN U-interface MC145572PBR2 pinout 44-LQFP ISDN 2B1Q transceiver 160 kbps MC145572PBR2 equivalent PEF2294N MC145572PBR2 drop-in replacement MC145572PBR2 buy stock LCSC MC145572 vs MC145574 U-interface what is the ISDN U-interface transceiver MC145572PBR2 NT mode LT mode strap obsolete ISDN transceiver Rochester Electronics

관련 부품 & 용어

NXP Semiconductors Freescale Semiconductor Motorola Semiconductor MC145572PBR2 MC145572 MC145574 ISDN U-interface ISDN Basic-Rate Access 2B1Q ANSI T1.601-1992 HDLC controller LAP-D adaptive echo canceller transceiver interface IC specialized IC 44-LQFP LQFP-44 LQFP 10x10 RoHS compliance Pb finish / SnPb tape and reel Network Termination (NT) Line Termination (LT) 5 V supply
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