Texas Instruments TMS3471C

Overview

TMS3471C from Texas Instruments is a monolithic NTSC timing generator IC designed specifically to drive the TI TC241 monochrome CCD image sensor. It delivers synchronized CCD drive signals (PI, PS, T, GT1–3), NTSC sync outputs (CSYNC, CBLK, BF, SC, SC(90)), and sample-and-hold pulses (SH1, SH2,3) using a single 5-V supply and 14.318-MHz crystal input. It operates from –20°C to 45°C in a 44-pin plastic flat package.

For engineers reviewing the TMS3471C datasheet, TMS3471C pinout, TMS3471C application, or TMS3471C equivalent, key selection considerations include NTSC-compatible timing accuracy, eight selectable antiblooming modes, clamp-pulse configuration options, vertical/horizontal counter synchronization, and compatibility with TI's TMS3472A/TMS3473B drivers and TL1593/TL1051 video signal processors.

Technical Context

The TMS3471C integrates a 14.318-MHz crystal oscillator, divide-by-4 and divide-by-7 logic to generate 3.58-MHz subcarrier and 2.045-MHz vertical timing, respectively. Its horizontal and vertical counters produce precisely timed gate clocks (HGATE, VGATE), transfer pulses (T), and storage/parallel-area clocks (PS, PI) aligned to NTSC 525-line/60-Hz frame structure.

It implements configurable antiblooming via ABS0–ABS2 inputs selecting among eight clocking modes (250 kHz–2.2 MHz, flyback-only or continuous), while BCPS0/BCPS1 control optical black clamp pulse placement relative to horizontal scan. E/L selects early/late serial-transfer timing versus sample-and-hold, and VDS sets vertical-dump frequency (1 MHz or 2 MHz) or functions as a reset input.

Key Specifications

Pinout & Package

Package: FS/S-PQFP-G44 - 44-pin plastic quad flatpack with 0.55 mm max lead pitch, 17.40–18.20 mm body length, and 14.20 mm max square footprint.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar NTSC timing generator applications.

Compared with TMS3471C, TMS3471 offers wider temperature margin above zero but no cold-start capability, while TMS3471A provides enhanced ESD protection without altering timing behavior - making it the recommended upgrade path for reliability-critical deployments where the –20°C lower limit is not mandatory.

Availability

TMS3471C is available at Aetrix Electronics and suitable for monochrome CCTV cameras, industrial machine vision sensors, medical endoscope modules, and legacy broadcast equipment repair requiring stable component supply and long-lifecycle support.

Supply support for TMS3471C 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

Texas Instruments is a global semiconductor company founded in 1930, specializing in analog, embedded processing, and digital signal technologies with broad industrial and automotive reach.

The TMS3471C belongs to TI's legacy imaging timing product line, engineered specifically to support 2/3-inch monochrome CCD sensors like the TC241 in NTSC-standard video acquisition systems.

FAQ

What is the primary function of the TMS3471C in a CCD imaging system?

The TMS3471C serves as the core NTSC timing generator for 2/3-inch monochrome CCD sensors such as the TI TC241. It produces all essential drive signals - including parallel-storage (PS), parallel-image (PI), and transfer-gate (T) clocks - along with NTSC synchronization outputs (CSYNC, CBLK, BF, SC, SC(90)) and sample-and-hold pulses (SH1, SH2,3). Its design eliminates the need for discrete timing logic in broadcast-compliant monochrome video systems.

Does the TMS3471C support both interlaced and noninterlaced scanning modes?

Yes, the TMS3471C supports both interlaced and noninterlaced operation via the I/N (interlace select) input. When I/N is high, the device generates timing for interlaced NTSC fields (262.5 lines per field); when low, it configures for noninterlaced (progressive) scanning. This flexibility allows use in both traditional CCTV and specialized machine vision applications requiring full-frame capture.

How does the TMS3471C implement antiblooming control, and what are the configuration options?

The TMS3471C implements antiblooming through the ABIN output and three digital inputs - ABS0, ABS1, and ABS2 - which select among eight distinct antiblooming modes. These modes define whether antiblooming pulses occur continuously or only during vertical flyback, and at frequencies of 250 kHz, 500 kHz, 1 MHz, or 2.2 MHz. The configuration is static and set at power-on, enabling optimization for specific lighting and scene-dynamic-range requirements.

Can the TMS3471C operate with a 5-V supply only, or does it require additional voltage rails?

The TMS3471C operates exclusively from a single 5-V supply (VCC = 4.5 V to 5.5 V), with no auxiliary voltage rails required. All internal circuitry - including the crystal oscillator, counters, logic, and output drivers - is designed for 5-V CMOS/TTL compatibility. Ground (GND) is the sole reference, and unused inputs must be tied to VCC or GND to prevent floating states that could increase power consumption or cause erratic timing.

What is the role of the VDS pin on the TMS3471C, and how does it affect vertical timing?

The VDS pin on the TMS3471C controls vertical-dump speed: when high, it selects a 2.045-MHz vertical-dump frequency; when low, it selects 1.022-MHz. Additionally, VDS can serve as a hardware reset input - dropping its voltage from VCC to VCC/2 and back triggers a timer reset. This dual function enables both frame-rate adaptation and safe recovery from timing lock-up without requiring external logic.