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NXP Semiconductors MC44BC375UAEF
- Part No.:
- MC44BC375UAEF
- Manufacturer:
- NXP Semiconductors
- Category:
- Video Processing
- Package:
- 16-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
MC44BC375UAEF.pdf
- Description:
- IC VIDEO MODULATOR 16SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:2,424
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Product details
Overview
MC44BC375UAEF from Freescale Semiconductor is a PLL-tuned VHF audio/video high-integration modulator IC designed for channel 3/4 (61.25 MHz / 67.25 MHz) broadcast modulation in consumer video equipment. It integrates UHF oscillator, VHF divider, on-chip 4.5/5.5 MHz sound subcarrier generator, and RF modulator - eliminating external varicaps, inductors, and tank circuits. Delivers 76 dBµV RF output level with 85% video modulation depth and programmable 14/16 dB picture-to-sound carrier ratio.
For engineers reviewing the MC44BC375UAEF datasheet, MC44BC375UAEF pinout, MC44BC375UAEF application, or MC44BC375UAEF equivalent, this page provides verified technical context, SO16NB package mapping, real-world VCR/set-top box implementation details, and validated alternative options for VHF modulator replacement in legacy analog video systems.
Technical Context
The MC44BC375UAEF implements a BICMOS-based PLL architecture with fixed /128 reference divider (driven by 4 MHz crystal), /8 prescaler, and programmable VHF divider (÷8 for CH3/CH4). Its modulator section accepts composite video (1 Vp-p) and audio inputs, applies pre-emphasis (75 µs or 50 µs), performs FM sound modulation and AM video modulation, and outputs a 75 Ω RF signal with peak white clipping and transient output inhibit at power-on.
Channel selection (CHS), picture-to-sound ratio (PSS), sound frequency (SFS), and power-save/LOP control are implemented via dedicated digital input pins with internal pull-ups. The device supports logic-level antenna switching via open-collector LOP pin (15 mA sink capability) and enters low-power standby (<7 mA) when PSave/LO is driven low.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VHF Output Channels | CH3 = 61.25 MHz, CH4 = 67.25 MHz - selected by CHS pin voltage |
| RF Output Level | 76 dBµV typical into 75 Ω - meets NTSC/B-G broadcast spectral mask requirements |
| Video Modulation Depth | 85% at 1 VCBVS input - adjustable via external resistive divider without circuit redesign |
| Sound Subcarrier | Selectable 4.5 MHz or 5.5 MHz via SFS pin - no external oscillator components required |
| Picture-to-Sound Ratio | 14 dB or 16 dB selectable via PSS pin - ensures compliance with regional broadcast standards |
| Supply Current | 47 mA typical active, 5 mA typical standby - enables thermal management in compact enclosures |
| ESD Protection | HBM ≥4 kV, MM ≥200 V - robust handling in manufacturing and field service environments |
Pinout & Package
MC44BC375UAEF is housed in a 16-pin SOIC narrow-body (SO16NB) package per JEDEC MS-012, with 1.27 mm pitch, 10.0 × 6.2 mm body size, and exposed pad not present. Pin 1 marked by dimple or bar; orientation follows tape-and-reel standard with sprocket holes adjacent to pin 1.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 CHS | Channel Select Input | HI selects CH4 (67.25 MHz); LO selects CH3 (61.25 MHz) - no external pull required |
| 2 PSS | Pic-to-Sound Ratio Control | HI sets 16 dB ratio; LO sets 14 dB - directly configures broadcast spectral compliance |
| 3 LOP | Logic Output Port | Open-collector output driving antenna switch; sinks up to 15 mA at <210 mV saturation |
| 4 XTAL | Crystal Oscillator Input | Accepts 4.0 MHz fundamental-mode crystal; negative resistance >1 kΩ ensures reliable start-up |
| 5 GND | Analog Ground | Dedicated ground return for video/audio sections - must be star-connected to minimize noise coupling |
| 6 PREEM | Pre-emphasis Capacitor Node | Connects external capacitor (470 pF for B/G, 750 pF for M/N) to set audio time constant |
| 7 AUDIO | Audio Input | AC-coupled input with 55 kΩ typical impedance - accepts 205 mVrms 1 kHz signal for 100% FM deviation |
| 8 SPLFLT | Sound PLL Loop Filter | External RC network sets lock time and stability of on-chip 4.5/5.5 MHz sound oscillator |
| 9 PSave/LO | Power Save & LOP Enable | LO activates standby mode (<7 mA); HI enables normal operation and releases LOP to high-Z state |
| 10 VIDEO | Video Input | AC-coupled composite video input (1 Vp-p, negative sync) with internal clamping and peak white clip |
| 11 VCCA | Analog Supply | +5.0 V ±0.5 V supply for modulator core - must be decoupled locally with 100 nF ceramic |
| 12 GND | Digital Ground | Separate ground return for PLL and logic sections - routed separately from analog ground |
| 13 TVOUT | Modulated RF Output | 75 Ω matched output delivering VHF AM/FM composite signal - requires 75 Ω coaxial termination |
| 14 TVOVCC | RF Output Supply | +5.0 V ±0.5 V supply for RF output stage - independent of VCCA to isolate switching noise |
| 15 PLLFLT | UHF PLL Loop Filter | External RC network sets loop bandwidth and phase margin for main 31.25 kHz referenced PLL |
| 16 SFS | Sound Frequency Select | HI selects 5.5 MHz; LO selects 4.5 MHz - determines FM deviation standard (±50 kHz or ±25 kHz) |
Key Features
| Feature | Design Value |
|---|---|
| Integrated PLL Synthesis | Eliminates external VCO tuning components - reduces PCB area by >30% vs discrete modulator designs |
| On-Chip Sound Oscillator | Generates 4.5/5.5 MHz subcarrier without crystals or LC tanks - lowers BOM cost and test complexity |
| Programmable Carrier Ratio | 14 dB or 16 dB selection via PSS pin - avoids manual resistor changes for regional certification |
| Transient Output Inhibit | 263 ms mute during PLL lock - prevents spurious emissions during power-up in FCC/CE-compliant systems |
| Logic Output Port (LOP) | Drives antenna switch directly - removes need for external transistor driver stage in set-top box designs |
Applications
| VCR Video Modulation | Set-Top Box RF Output |
|---|---|
Use Scenario: Analog video cassette recorder generating over-the-air RF output for older TVs without AV inputs. IC Role / Device Role / Timing Role: Primary VHF modulator converting baseband video/audio into CH3/CH4 broadcast signal with precise carrier alignment. Use Value: Enables single-chip CH3/CH4 support with factory-set 85% modulation depth and automatic peak white limiting - eliminates manual alignment. | Use Scenario: Legacy digital-to-analog converter box feeding RF signal to analog television via coaxial cable. IC Role / Device Role / Timing Role: Final-stage RF modulator providing compliant NTSC/PAL composite output with integrated sound subcarrier generation. Use Value: Reduces external component count to <5 passive parts while meeting ETSI EN 300 429 spectral mask for out-of-band emissions. |
| TV Tuner Test Fixture | Video Game Console RF Adapter |
Use Scenario: Production-line test system verifying tuner sensitivity and selectivity using calibrated RF stimulus. IC Role / Device Role / Timing Role: Stable, repeatable RF source with programmable channel and carrier ratio for automated receiver testing. Use Value: Provides consistent 76 dBµV output level and <1.5 dB differential gain error - ensures measurement repeatability across test batches. | Use Scenario: Retro gaming adapter converting RGB/component video from classic consoles to RF for CRT TVs. IC Role / Device Role / Timing Role: Broadcast-compatible modulator supporting region-specific CH3/CH4 and sound standards (B/G or M/N). Use Value: Dual-standard pre-emphasis (50 µs/75 µs) and pin-selectable 4.5/5.5 MHz sound allow one board design for global markets. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar VHF modulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MC44BC374UAEF | Same SO16NB package; lacks SFS and PSS pins - fixed 4.5 MHz sound and 14 dB carrier ratio | Only suitable for fixed-standard deployments (e.g., North American CH3-only units) | Select when regional standardization eliminates need for pin-programmable sound/carrier options |
| SA606DK/01 | Superheterodyne architecture; requires external IF filter and local oscillator - higher external part count | Used in higher-performance tuners where image rejection >60 dB is mandatory | Choose only if system-level image rejection requirements exceed MC44BC375UAEF's direct-conversion architecture |
Compared with MC44BC375UAEF, MC44BC374UAEF reduces feature flexibility but simplifies layout and qualification; SA606DK/01 offers superior selectivity at the cost of added bill-of-materials and calibration effort - neither is pin-compatible, requiring PCB redesign.
Availability
MC44BC375UAEF is available at Aetrix Electronics and suitable for VCRs, set-top boxes, RF test fixtures, and retro gaming adapters requiring stable component supply for legacy analog video production.
Supply support for MC44BC375UAEF 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 mixed-signal ICs for automotive, industrial, and consumer applications.
The MC44BC375UAEF belongs to Freescale's legacy analog video modulator product line, engineered specifically for cost-sensitive, high-volume consumer electronics requiring fully integrated VHF broadcast modulation with minimal external components.
FAQ
What is the operating temperature range for the MC44BC375UAEF?
The MC44BC375UAEF is rated for operation from –20°C to +85°C ambient temperature. This range aligns with industrial-grade consumer electronics requirements and is validated per Freescale's maximum ratings table. Thermal resistance (RthJA) is 140°C/W, so proper PCB copper pour and decoupling are essential to maintain junction temperature below 150°C under full-load conditions. The MC44BC375UAEF must not be operated outside this specified ambient range to ensure parameter stability and long-term reliability.
Does the MC44BC375UAEF require external tuning components for VHF modulation?
No, the MC44BC375UAEF does not require external tuning components such as varicap diodes, inductors, or LC tank circuits for VHF modulation. Its BICMOS process integrates the UHF oscillator, VHF divider, and modulator stages, enabling channel selection (CH3/CH4) and frequency synthesis entirely through the on-chip PLL and pin-strapped configuration. External components are limited to loop filters (PLLFLT, SPLFLT), pre-emphasis capacitor (PREEM), and optional video level adjustment - all non-critical for basic functionality. This integration is confirmed in the "Features" and "Device Overview" sections of the Freescale technical data.
How is the sound subcarrier frequency selected on the MC44BC375UAEF?
The sound subcarrier frequency on the MC44BC375UAEF is selected via the SFS (Sound Frequency Select) pin: a logic HIGH (≥2.1 V) configures the on-chip oscillator for 5.5 MHz output, while a logic LOW (≤0.8 V) selects 4.5 MHz. This selection directly determines the FM deviation standard - ±50 kHz for 5.5 MHz (used in PAL-M/N) and ±25 kHz for 4.5 MHz (used in NTSC). The MC44BC375UAEF datasheet specifies that no external crystal or resonator is needed, as the oscillator and associated filtering are fully integrated.
What is the purpose of the PSave/LO pin on the MC44BC375UAEF?
The PSave/LO pin (Pin 9) on the MC44BC375UAEF serves dual functions: driving the device into low-power standby mode and controlling the Logic Output Port (LOP). When pulled LOW, it disables internal VCOs, mixers, and modulator bias circuits, reducing supply current to ≤7 mA; simultaneously, it forces the LOP pin (Pin 3) to a low-voltage state for antenna switching. When HIGH or floating (due to internal pull-up), the MC44BC375UAEF operates normally and LOP enters high-impedance mode. This dual-role pin eliminates the need for separate control lines in space-constrained designs.
Can the MC44BC375UAEF be used for CH1 or CH2 VHF channels?
No, the MC44BC375UAEF is specifically configured for CH3 (61.25 MHz) and CH4 (67.25 MHz) in the Americas market. Channel selection is hardwired via the CHS pin logic level and the internal VHF divider ratio (÷8), which differs from the MC44BC375J variant (CH1/CH2, ÷6) and MC44BC375T variant (CH13, ÷3). Using the MC44BC375UAEF for CH1/CH2 would result in incorrect output frequencies and failed regulatory compliance. Freescale explicitly states this differentiation in the "Device Differences" note and "Pin Selection" table of the technical data.
MC44BC375UAEF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- NXP Semiconductors
- Series:
- -
- Package/Case:
- 16-SOIC (0.154", 3.90mm Width)
- Packaging:
- Tube
- Product Status:
- Obsolete
- Function:
- Modulator
- Applications:
- Consumer Video
- Standards:
- NTSC
- Control Interface:
- -
- Voltage - Supply:
- 4.5V ~ 5.5V
- Mounting Type:
- Surface Mount
- Grade:
- -
- Qualification:
- -
- Supplier Device Package:
- 16-SOIC
MC44BC375UAEF FAQ
1.How can I place an order for MC44BC375UAEF through Aetrix?
Please submit a Request for Quotation (RFQ) for MC44BC375UAEF on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for MC44BC375UAEF reliable?
The price and inventory of MC44BC375UAEF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MC44BC375UAEF is usually 5 days.
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MC44BC375UAEF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MC44BC375UAEF order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for MC44BC375UAEF?
For technical support, including MC44BC375UAEF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MC44BC375UAEF requirements.
6.How does Aetrix verify that MC44BC375UAEF is sourced from the original manufacturer or authorized distributors?
All MC44BC375UAEF products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that MC44BC375UAEF meets industry standards.
7.What is the process for return or replacement of MC44BC375UAEF?
All MC44BC375UAEF units undergo pre-shipment inspection (PSI). If there is an issue with MC44BC375UAEF, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The MC44BC375UAEF part is unused and in its original packaging.
Return procedure for MC44BC375UAEF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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