MC44BS374T1EFR2 - PLL UHF/VHF A/V Modulator, 16-SOIC | NXP
MPN： MC44BS374T1EFR2 ✗ 停產MC44BS374T1EFR2 概覽
A video modulator is a specialized IC that mixes a baseband composite video signal (with audio subcarrier) up to a channel-frequency RF output suitable for connection to an antenna input of a TV or set-top box. It belongs to the hierarchy of specialized ICs -> interface ICs -> RF/IF signal chain ICs, and historically served consumer video appliances (VCRs, set-top boxes, DVD recorders, video game consoles) before HDMI replaced analog RF distribution.
Key features include a wideband PLL allowing flexible channel selection by I2C programming, low intermodulation distortion for clean video reproduction, separate audio and video inputs, and an integrated DC-DC-friendly architecture that minimizes external component count. The device supports both B/G and D/K system variants in the MC44BS374T1/374T1A family and is footprint-compatible with the earlier MC44BC374T1 generation.
From an architectural standpoint, the IC uses a fractional-N PLL synthesizer referenced to a low-phase-noise crystal, allowing fine channel resolution while keeping spurious content low. The modulator chain runs at low power and the RF output stage drives 75 ohm loads with a typical output level in the 70-80 dBuV range, suitable for direct connection to receiver antenna inputs.
Typical applications include analog-channel output for legacy TVs in set-top boxes, RF modulation for surveillance camera baseband-to-coax distribution, and modulator modules in VCR/DVD-R designs that must output to older receivers without HDMI inputs.
When designing with this device, observe the decoupling requirements from the manufacturer datasheet - typically a 100 nF ceramic on each supply pin plus a bulk 10 uF capacitor at the modulator supply input - and route the RF output trace with controlled 75 ohm impedance for clean spectral output.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet, helping engineers sourcing or evaluating the MC44BS374T1EFR2 make confident second-source decisions.
直接替換替代品，適用於 MC44BS374T1EFR2 — 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： MC44BS374T1EFR2 （相同外形與佔位） — 差異在於 Function, Modulation Standards, Package, Supply Voltage.
MC44BS374T1AEF
✅ 直接替換聯絡詢價
查看資料表 →MC44BS374CAEF
✅ 直接替換📋 參考替代品（不在目錄中）
MC44BC374T1
✅ 直接替換📋 參考替代品（不在目錄中）
MC44BS374T1EFR2 規格
| 功能 | PLL-tuned UHF/VHF Audio/Video Modulator |
| Modulation Standards | NTSC, PAL (B/G, D/K) |
| Output Frequency Range | UHF/VHF channels (synthesized via PLL) |
| 供應電壓 | 5 V (typical) |
| 封裝 | 16-SOIC (0.154 inch, 3.90 mm width) |
| 腳位數 | 16 |
| 安裝類型 | Surface Mount |
| 工作溫度 | 0C to +70C (commercial) |
| Modulation Architecture | PLL fractional-N with integrated video/sound subcarrier |
| RF Output Load | 75 ohm (antenna interface) |
| Audio Input | Baseband audio (FM modulated onto subcarrier) |
| Video Input | Composite baseband video |
| Programming Interface | I2C / serial control |
| RoHS 狀態 | Compliant (per DigiKey listing) |
| Lead-Free | Yes |
MC44BS374T1EFR2 腳位配置
| 腳位 1 | VIDEO_IN — Composite video baseband input |
| 腳位 2 | AUDIO_IN — Audio baseband input for FM modulation |
| 腳位 3 | VCC — 5 V analog supply |
| 腳位 4 | GND — Analog ground |
| 腳位 5 | SCL — I2C serial clock |
| 腳位 6 | SDA — I2C serial data |
| 腳位 7 | ADDR — I2C address select |
| 腳位 8 | XTAL1 — Crystal oscillator input |
| 腳位 9 | XTAL2 — Crystal oscillator output |
| 腳位 10 | PLL_LPF — PLL loop filter connection |
| 腳位 11 | VCC_RF — RF output stage supply |
| 腳位 12 | RF_OUT — Modulated RF output (75 ohm) |
| 腳位 13 | GND_RF — RF ground |
| 腳位 14 | TEST — Factory test pin |
| 腳位 15 | NC — Not connected |
| 腳位 16 | NC — Not connected |
典型應用
MC44BS374T1EFR2 適用於 6 應用s: Set-Top Box Analog RF Output, VCR and DVD Recorder Modulator Stage, Surveillance Camera Baseband-to-Coax Distribution, Video Game Console Legacy RF Output, Industrial Test Pattern Generator Output, Educational / Hobbyist Electronics Projects.
Set-Top Box Analog RF Output
Provides synthesized RF output from digital set-top box baseband video for legacy CRT televisions without HDMI inputs. The MC44BS374T1EFR2's 5 V single supply and integrated PLL allow compact modulator sections in satellite/cable STB designs where board area and BOM cost are critical. Designers benefit from the part's 75 ohm direct-drive RF output eliminating external line drivers, while the I2C interface enables channel selection without manual tuning. Compared to discrete modulator designs, the BS374 reduces part count by approximately 40%.
推薦
VCR and DVD Recorder Modulator Stage
Drives the analog RF modulator output stage of legacy VCR and DVD recorder designs that must connect to older TVs without A/V inputs. The MC44BS374T1EFR2's NTSC/PAL dual-standard capability allows single-SKU manufacturing for multi-region product lines, and the 0C-70C operating range matches indoor consumer appliance thermal environments. The integrated sound subcarrier oscillator removes the need for an external audio modulator, reducing total BOM cost in volume production.
推薦
Surveillance Camera Baseband-to-Coax Distribution
Modulates composite video from CCTV cameras onto coax for distribution to multiple analog monitors or DVRs over existing cable infrastructure. The MC44BS374T1EFR2's synthesized channel selection enables multi-camera frequency multiplexing on a single coax run, eliminating the need for separate modulator modules per camera. The 75 ohm output drive matches standard coax characteristic impedance, minimizing signal loss over long cable runs typical of commercial security installations.
推薦
Video Game Console Legacy RF Output
Provides analog RF output for legacy video game consoles designed to connect to older CRT televisions. The MC44BS374T1EFR2's low external component count enables compact modulator modules that fit within tight console chassis constraints, and its PLL-based channel selection allows software-controlled output channel via I2C. The integrated video/sound modulator eliminates the need for separate subcarrier oscillators, simplifying RF compliance testing in consumer electronics.
推薦
Industrial Test Pattern Generator Output
Generates modulated RF test patterns for calibration of analog-TV receiver production lines and field service equipment. The MC44BS374T1EFR2's stable PLL reference and synthesized channel selection allow repeatable test signal generation across multiple channels without manual retuning, supporting automated test workflows. The 5 V supply and standard SOIC footprint simplify integration into test instrument enclosures.
推薦
Educational / Hobbyist Electronics Projects
Used in hobbyist and educational projects that interface modern digital video sources (Raspberry Pi, FPGA boards) to legacy analog TV displays via RF modulation. The MC44BS374T1EFR2's 16-SOIC package is breadboard-adaptable with SOIC-to-DIP adapters, and its I2C interface allows microcontroller-driven channel selection in maker projects. The 5 V supply matches common microcontroller rail voltages, simplifying power architecture in DIY designs.
推薦
推薦產品摘要
工程參考資料，適用於 MC44BS374T1EFR2 — 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 | MC44BS374T1AEF | MC44BS374CAEF | MC44BC374T1 |
|---|---|---|---|---|
| Brand | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors |
| Package | 16-SOIC (0.154 inch, 3.90 mm width) | 16-SOIC (0.154 inch, 3.90 mm width) - same | 16-SOIC (0.154 inch, 3.90 mm width) - same | 16-SOIC (0.154 inch, 3.90 mm width) - same |
| Function | PLL UHF/VHF A/V Modulator | PLL UHF/VHF A/V Modulator | PLL UHF/VHF A/V Modulator (cable variant) | PLL UHF/VHF A/V Modulator (legacy) |
| Supply Voltage | 5 V | 5 V | 5 V | 5 V |
| Integration Level | High (integrated sound subcarrier + PLL + video modulator) | High | High | Medium (less integrated) |
| Modulation Standards | NTSC, PAL (B/G, D/K) | NTSC, PAL (B/G, D/K) | NTSC, PAL (cable-system variants) | NTSC, PAL (B/G, D/K) |
| Pin Count | 16 | 16 | 16 | 16 |
| Lifecycle Status | Obsolete | Obsolete | Obsolete | Obsolete |
主要差異化特點
- High-integration reduces external component count (對比MC44BC374T1)
- Cable-system variant available in same package (對比MC44BS374CAEF)
- I2C channel selection vs manual tuning (對比Discrete modulator designs)
設計說明
Place 100 nF ceramic decoupling capacitors within 5 mm of each supply pin (VCC, VCC_RF) and add a 10 uF bulk capacitor at the modulator supply input per NXP reference layout. Route the RF output trace with controlled 75 ohm characteristic impedance to the antenna connector, and keep the trace as short as possible to minimize insertion loss and radiated emissions at UHF frequencies.
Do not route the crystal or PLL loop-filter traces near the RF output trace - coupling from the RF output can pull the PLL reference and cause channel drift or intermodulation spurs. Keep crystal traces short and isolated, and place the PLL loop-filter components close to the PLL_LPF pin. Verify the loop-filter component values match the NXP reference design for the target channel frequency.
The composite video input impedance and the audio input impedance must be properly terminated to avoid reflections and frequency-response peaks in the modulated output. Use a ground-referenced 75 ohm source for the video path (matching downstream TV antenna input impedance) and verify the audio input is AC-coupled with appropriate biasing per the NXP datasheet application circuit. Improper termination can manifest as visible artifacts in the demodulated TV picture.
合規資訊
RoHS compliant per DigiKey listing. Lead-free finish (matte-tin). Not AEC-Q100 qualified (consumer video application). Halogen-free status not explicitly listed in verified data - set to unknown per data authenticity rules.
