Texas Instruments TLC8044CFN

Overview

TLC8044CFN from Texas Instruments is a 12-bit analog-to-digital interface IC designed specifically for CCD image sensors in flatbed and handy scanners. It integrates a 3-channel differential RGB multiplexer, three 8-bit+sign DACs for bipolar dc offset correction, correlated double sampling (CDS) capability, 6 MSPS ADC operation, and pixel-by-pixel digital dc restoration and shading compensation. It supports 600 dpi CCD sensors and operates from 0°C to 70°C.

For engineers reviewing the TLC8044CFN datasheet, TLC8044CFN pinout, TLC8044CFN application, or TLC8044CFN equivalent, this page delivers verified functional identity, validated 68-pin PLCC package mapping, confirmed CDS/normal sampling modes, calibrated DAC reference voltages (2.5 V), and real-world scanner system integration context - all critical for CCD signal chain design and BOM validation.

Technical Context

The TLC8044CFN implements a pipelined 12-bit ADC with programmable 8/10/12/16-bit output word length and dual internal default registers for even/odd pixel offset correction. Its DSP-based architecture performs real-time pixel-by-pixel offset and gain (shading) compensation using external 12-bit POC and PSC coefficient data streams synchronized to the multiplexed pixel rate.

It supports two sampling architectures: DAC-referenced normal sampling and correlated double sampling (CDS), with MCLK operating at 12 MHz max and VSMP timing defining sample alignment. Input configuration includes selectable single-ended or fully differential mode via serial interface control, with RU/RL/RT/RB terminals enabling precise 2.5 V full-scale ADC range derivation from a 5 V reference.

Key Specifications

Pinout & Package

68-terminal plastic leaded chip carrier (PLCC) package with standard 0.050″ pitch and JEDEC MO-047A outline. Pin 1 marked by corner notch; top-side view orientation matches datasheet FN package diagram.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar CCD analog-to-digital interface applications.

Compared with AD9845BSTZ and TLC8045CFN, the TLC8044CFN uniquely integrates CDS, dual pixel offset registers, and parallel POC/PSC coefficient loading - making it irreplaceable in cost-sensitive, volume scanner designs where system-level noise suppression and per-pixel correction are mandatory.

Availability

TLC8044CFN is available at Aetrix Electronics and suitable for flatbed scanners, handheld document scanners, color calibration systems, and OCR-optimized image preprocessing requiring stable component supply and long-term BOM continuity.

Supply support for TLC8044CFN 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 U.S.-based semiconductor company founded in 1930, specializing in analog, embedded processing, and high-performance data converters for industrial, automotive, and consumer applications.

The TLC8044CFN belongs to TI's legacy CCD interface product line, engineered specifically to replace multi-chip analog front-ends in document imaging systems with a single integrated solution supporting RGB color, CDS, and real-time digital correction.

FAQ

What is the primary function of the TLC8044CFN in a scanner system?

The TLC8044CFN serves as the dedicated analog-to-digital interface between CCD image sensors and digital processing units in flatbed and handheld scanners. It digitizes RGB video signals at up to 6 MSPS, applies correlated double sampling to suppress reset noise, performs pixel-by-pixel offset and shading correction using external coefficient data, and outputs programmable-length digital words. Its integrated DACs, CDS logic, and coefficient interfaces make the TLC8044CFN a complete front-end subsystem - eliminating the need for discrete op-amps, DACs, and timing controllers in scanner designs.

Does the TLC8044CFN support both color and monochrome CCD sensors?

Yes, the TLC8044CFN natively supports both color and monochrome operation. In color mode, its 3:1 differential multiplexer sequentially samples R/G/B channels synchronized to the VSMP pulse, delivering a 6 MSPS serial stream. In monochrome mode, it locks onto a single channel (R, G, or B selected via serial register) and samples continuously at up to 6 MSPS. The device also offers fast monochrome (4 MSPS) and max-speed monochrome (6 MSPS) modes, all configurable through its serial interface - ensuring full flexibility across scanner product tiers using the same TLC8044CFN footprint.

How does the TLC8044CFN implement correlated double sampling (CDS)?

The TLC8044CFN implements CDS by capturing two successive samples per pixel: one during the CCD reset (dark) period and one during the active video period. These samples are subtracted internally to cancel reset noise and fixed-pattern offsets. CDS mode is enabled via serial interface register bits (CDSR1/CDSR0), and timing is controlled by the VSMP pulse aligned to MCLK. Unlike external CDS solutions, the TLC8044CFN performs subtraction digitally post-ADC, preserving 12-bit resolution while avoiding analog subtraction errors - a key advantage confirmed in the SLAS128 datasheet's CDS timing diagrams and mode summary table.

What are the voltage requirements for the TLC8044CFN reference terminals RT, RB, RU, and RL?

The TLC8044CFN requires RT = 3.75 V and RB = 1.25 V to establish its 2.5 V full-scale ADC range. These voltages are derived from a 5 V reference applied between RU and RL, which connect to extensions of the internal reference string. Per the datasheet, RU–RL impedance is 1190–2210 Ω, and the resulting DAC reference voltage is tightly regulated at 2.475–2.525 V. All four terminals must be capacitively decoupled externally; failure to maintain these precise reference levels degrades INL/DNL performance and invalidates the 12-bit specification - a requirement explicitly defined in the "Reference String" electrical characteristics table.

Can the TLC8044CFN output word length be changed dynamically during operation?

Yes, the TLC8044CFN supports dynamic reconfiguration of output word length (8, 10, 12, or 16 bits) via its serial interface without interrupting conversion. When set to 8/10/12-bit modes, OP15 functions as an under-range indicator (active high), while ORNG signals over-range conditions. This runtime flexibility allows systems to adapt data throughput to processing load - e.g., using 8-bit mode for preview scans and 12-bit for final capture. The feature is implemented in hardware and verified in the "Output Word Length Select" block of the functional diagram and timing figures 3–4 of the SLAS128 datasheet.