Texas Instruments TLC0820ACFN

Overview

TLC0820ACFN from Texas Instruments is an Advanced LinCMOS™ 8-bit analog-to-digital converter using modified flash architecture, featuring 1.18 µs conversion time, ±1 LSB total unadjusted error, differential reference inputs, and parallel TTL-compatible microprocessor interface. It operates from a single 5-V supply and integrates on-chip track-and-hold for continuous analog signals up to 100 mV/µs slew rate - used in high-speed data acquisition systems for industrial instrumentation and motor control feedback loops.

For engineers reviewing the TLC0820ACFN datasheet, TLC0820ACFN pinout, TLC0820ACFN application, or TLC0820ACFN equivalent, key selection criteria include its read/write dual-mode operation (MODE-selectable), overflow flag (OFLW) for cascaded resolution extension, interrupt-driven timing (INT), and compatibility with legacy 8-bit microcontrollers via WR/RDY and RD control signals.

Technical Context

The TLC0820ACFN implements a two-stage modified flash architecture: first, a 4-bit flash ADC digitizes the MSBs; then a precision 4-bit DAC generates a reconstructed analog voltage, whose difference from the input is measured by a second 4-bit flash ADC for the LSBs. This architecture achieves full 8-bit resolution without external clocking or sampling components.

It supports two distinct interface modes: Read Mode (MODE = low), where RD initiates conversion and WR/RDY acts as a ready output; and Write-Read Mode (MODE = high), where WR/RDY initiates conversion and INT signals completion after ~800 ns. Both modes use CS for device selection and provide 3-state digital outputs (D0–D7) with TTL-level compatibility.

Key Specifications

Pinout & Package

PLCC-20 (FN package), 0.9-inch square body, 1.27 mm lead pitch, J-lead configuration with pin 1 index corner. RoHS-compliant, obsolete but available through authorized channels.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 8-bit parallel ADC applications.

Compared with ADC0820CCN and AD7820KN, the TLC0820ACFN delivers superior speed and integrated track-and-hold in a LinCMOS process, making it optimal for real-time control loops - whereas ADC0820CCN trades power for legacy equivalence, and AD7820KN prioritizes low power over throughput.

Availability

TLC0820ACFN is available at Aetrix Electronics and suitable for industrial instrumentation, motor control feedback, and legacy microcontroller interface applications requiring stable component supply and long-term obsolescence management.

Supply support for TLC0820ACFN 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 leader specializing in analog, embedded processing, and connectivity technologies, with decades of expertise in precision data conversion and industrial-grade IC design.

The TLC0820A family was developed for high-speed, low-latency 8-bit digitization in resource-constrained industrial and control systems - emphasizing interface flexibility, on-chip integration, and compatibility with legacy 8-bit microprocessors.

FAQ

What is the maximum analog input slew rate supported by the TLC0820ACFN without external track-and-hold?

The TLC0820ACFN integrates an on-chip track-and-hold circuit with a 100-ns sample window, enabling accurate digitization of analog signals with slew rates up to 100 mV/µs. This specification is verified across the full operating temperature range (0°C to 70°C) and eliminates the need for external sampling components in most high-speed industrial sensing applications using the TLC0820ACFN.

Does the TLC0820ACFN require an external clock or oscillator to operate?

No, the TLC0820ACFN does not require an external clock or oscillator. Its modified flash architecture and internal timing logic enable autonomous conversion initiation and completion using only control signals (RD, WR/RDY, CS, and MODE). This self-timed operation simplifies system design and removes clock distribution and jitter concerns - a confirmed feature of the TLC0820ACFN per its datasheet SLAS064A.

How does the MODE pin affect the interface timing behavior of the TLC0820ACFN?

The MODE pin selects between two distinct interface protocols: when MODE is low, the TLC0820ACFN operates in Read Mode (RD initiates conversion, WR/RDY acts as ready output); when MODE is high, it enters Write-Read Mode (WR/RDY initiates conversion, INT signals completion after ~800 ns). These modes are electrically and functionally separate - the TLC0820ACFN's timing diagrams (Figures 1–4) confirm mode-dependent delays including td(int), ta(R1), and td(WR).

Can the TLC0820ACFN be used to achieve more than 8-bit resolution?

Yes, the TLC0820ACFN includes an overflow flag (OFLW) specifically designed to cascade multiple units. As shown in Figure 6 of the datasheet, two TLC0820ACFN devices can be configured in master-slave arrangement to deliver 9-bit resolution - the master's OFLW controls the slave's conversion trigger, and results are combined in software or logic. This capability is intrinsic to the TLC0820ACFN's architecture and requires no external components beyond standard interconnect.

Is the TLC0820ACFN pin-compatible with other industry-standard 8-bit ADCs?

Yes, the TLC0820ACFN is pin-compatible with National Semiconductor's ADC0820C/CC and Analog Devices' AD7820K/B/T in the 20-pin PDIP (N) and PLCC (FN) packages. The pin functions, electrical characteristics, and timing behavior align sufficiently to allow direct substitution in existing designs - a claim explicitly stated in the "TLC0820A Is Direct Replacement" section of the TLC0820ACFN datasheet SLAS064A.