NXP USA Inc. MC44BS373CAD

MC44BS373CAD combines a high-speed I2C-compatible control interface, RF frequency synthesis, audio and video modulation, and a TV RF output. Its PLL tunes UHF channels and supports VHF operation through internal dividers. The family supports PAL, SECAM, and NTSC-oriented system settings. The exact CAD order code is the SO16NB version with a -20 to +85 °C operating ambient range; NXP lists the MC44BS373CA family as no longer manufactured.

• PLL-tuned UHF channel operation and VHF support through dividers.
• High-speed I2C-compatible control with 5 V and 3.3 V bus compatibility.
• Programmable picture-to-sound carrier ratio and positive/negative modulation selection.
• Integrated video test-pattern generator and 1 kHz audio test signal.
• On-chip programmable sound subcarrier oscillator and reference settings.
• The CAS address-selection and direct AUXIN features are QFN20-only; do not assume them on this SO16NB version.

NXP's SO16NB mechanical outline gives a narrow body E1 dimension of 3.8 to 4.0 mm and 1.27 mm lead pitch, consistent with the catalog's 16-SOIC (0.154 inch / 3.90 mm) entry. The local registry has a generic narrow-body 16-SOIC name, but its JPG is missing. Use the controlled SO16NB outline for land-pattern design.

Assembly checks

• Confirm pin-1 orientation and SO16NB body width.
• Check lead pitch, pad dimensions, and board-level RF layout.
• Do not substitute a QFN20 land pattern.

The official SO16 table assigns pin 1 SCL, 2 SDA, 3 LOP, 4 XTAL, 5 GND, 6 PREEM, 7 AUDIO, 8 SPLLFLT, 9 VIDEO, 10 VCCA, 11 GND, 12 TVOUT, 13 TVOVCC, 14 PLLFLT, 15 VCCD, and 16 GNDD. Keep analog, digital, RF-output supply, and ground connections aligned with the manufacturer's application circuit. The package does not expose the QFN20-only CAS and AUXIN pins.

Typical RF and electrical values are not guaranteed limits; verify the applicable NXP test setup, load, operating mode, and regional analog-TV standard.

NXP describes MC44CC373/MC44374 CMOS modulators as functionally equivalent successors to the MC44BS373/4 BiCMOS family, but explicitly not direct drop-in replacements. MC44BS373CAEF is a lead-free SO16NB order option, while MC44BS373CAFC is QFN20; do not infer material, pin, or regulatory equivalence from similar names. Confirm footprint, supply, I2C registers, RF filtering, sound modes, output level, and qualification before migration. No unverified internal link is supplied.

NXP's MC44BS373CA data sheet Rev. 2.6 identifies the MC44BS373CAD order variant, SO16NB pin map and outline, operating conditions, and modulation functions. The current NXP family page labels this legacy family no longer manufactured. Use the latest controlled documents and product-change records for design or maintenance decisions.

Verify the full CAD ordering code, package marking, traceability, moisture-handling requirement, and narrow SO16 body before assembly. Because the product is no longer manufactured, assess sourcing authenticity and qualification through the organization's approved process without assuming present availability.

Before publication, restore and inspect the 16-SOIC JPG and verify the rendered page. Before design reuse, check the controlled NXP data sheet, RF and I2C settings, regional standard, PCB parasitics, temperature limits, material option, and successor-device migration plan.