NXP Semiconductors MC44BC375UAEFR2

Overview

MC44BC375UAEFR2 from Freescale Semiconductor is a PLL-tuned VHF audio/video modulator IC for CH3/CH4 broadcast channels (Americas), integrating UHF oscillator, VHF divider, sound subcarrier generator, and envelope modulator in a single SO16NB package. It delivers 76 dBµV RF output level, supports 4.5 MHz or 5.5 MHz sound subcarrier selection via SFS pin, enables 14 dB or 16 dB picture-to-sound carrier ratio via PSS pin, and operates from 4.5 V to 5.5 V supply with 47 mA typical active current. It targets VCRs and set-top boxes requiring fully integrated analog TV modulation.

For engineers reviewing the MC44BC375UAEFR2 datasheet, MC44BC375UAEFR2 pinout, MC44BC375UAEFR2 application, or MC44BC375UAEFR2 equivalent, key selection considerations include channel-specific VHF divider ratio (8 for CH3/CH4), integrated 4 MHz crystal-based PLL reference, programmable power-save mode with logic output port (LOP), peak-white clipping, and absence of external varicaps or tank components.

Technical Context

The MC44BC375UAEFR2 implements a dual-loop PLL architecture: a UHF oscillator (divided by 8 for VHF output) locked to a 4 MHz crystal via a /128 reference divider yielding 31.25 kHz, and a separate sound PLL generating 4.5 MHz or 5.5 MHz subcarriers. Both loops use charge-pump phase-frequency detectors with externally filtered loop responses (PLLFLT and SPLFLT pins).

Modulation is performed via analog envelope modulation - video input (1 V_p-p, AC-coupled, clamped sync tip) drives a peak-white clipped modulator stage, while audio (pre-emphasis enabled) feeds an FM modulator. The device includes dedicated LOP open-collector output (15 mA sink capability) for antenna switching and transient output inhibit (263 ms delay at power-on to prevent spurious emissions during PLL lock).

Key Specifications

Pinout & Package

MC44BC375UAEFR2 is housed in a 16-pin SO16NB (Small Outline Integrated Circuit, narrow body) package per JEDEC MS-012, with 1.27 mm pitch, 10.0 mm × 6.2 mm body size, and exposed pad not present. Pin 1 is marked by a dot/dimple adjacent to sprocket holes on tape-and-reel packaging (R2 suffix).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar VHF analog TV modulator applications.

Compared with MC44BC375UAEFR2, MC44BC374UAEFR2 sacrifices sound integration for marginally lower cost but increases BOM and layout effort, while SA606DK/01 serves entirely different signal-chain roles and cannot fulfill the modulator function - making MC44BC375UAEFR2 the sole production-ready integrated solution for CH3/CH4 VCR and STB applications.

Availability

MC44BC375UAEFR2 is available at Aetrix Electronics and suitable for VCRs, set-top boxes, and home AV recorders requiring stable component supply, long-lifecycle support, and guaranteed traceability for consumer electronics manufacturing.

Supply support for MC44BC375UAEFR2 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Freescale Semiconductor (now part of NXP Semiconductors) is a fabless semiconductor company specializing in analog, mixed-signal, and RF solutions for automotive, industrial, and consumer markets.

The MC44BC375UAEFR2 belongs to Freescale's legacy broadcast modulator product line, designed specifically for cost-sensitive, high-volume analog TV equipment requiring fully integrated, crystal-referenced VHF modulation with minimal external components.

FAQ

What is the operating temperature range for the MC44BC375UAEFR2?

The MC44BC375UAEFR2 is rated for operation from –20°C to +85°C ambient temperature. This industrial-grade range supports deployment in consumer electronics such as VCRs and set-top boxes that may experience elevated internal temperatures during extended playback or recording sessions. The device's thermal resistance (R_thJA) is 140°C/W, requiring appropriate PCB copper pour and airflow management for sustained full-load operation.

Does the MC44BC375UAEFR2 require external tuning components for VHF channel synthesis?

No, the MC44BC375UAEFR2 does not require external tuning components for VHF channel synthesis. Its integrated PLL uses a 4 MHz crystal and on-die UHF oscillator divided by 8 to generate CH3 (61.25 MHz) or CH4 (67.25 MHz) frequencies. No external varicaps, inductors, or tank circuits are needed - eliminating manual alignment and improving production yield and long-term stability.

How is the sound subcarrier frequency selected on the MC44BC375UAEFR2?

The sound subcarrier frequency on the MC44BC375UAEFR2 is selected via the SFS pin (Pin 16): applying logic HIGH yields 5.5 MHz (for PAL-B/G), while logic LOW yields 4.5 MHz (for NTSC-M). This selection is implemented using an on-chip multivibrator oscillator with internal low-pass filtering, ensuring low harmonic content (<–65 dBc) without external crystal or LC networks.

What is the purpose of the PSave/LO pin (Pin 9) on the MC44BC375UAEFR2?

The PSave/LO pin (Pin 9) on the MC44BC375UAEFR2 serves dual functions: driving the device into power-save mode (disabling internal VCOs, mixers, and modulators) when pulled LOW, and controlling the Logic Output Port (LOP) state. In power-save mode, LOP is automatically forced LOW to drive external antenna switches - enabling single-pin control of both low-power operation and RF path selection.

Can the MC44BC375UAEFR2 be used for CH1 or CH2 VHF channels?

No, the MC44BC375UAEFR2 is specifically configured for CH3 and CH4 (Americas band) and cannot be used for CH1 or CH2. Those channels are supported only by the MC44BC375JD variant (Japan band), which uses a different VHF divider ratio (6 instead of 8) and distinct pin behavior on CHS. Using MC44BC375UAEFR2 for CH1/CH2 would result in incorrect output frequency and failed regulatory compliance.