Texas Instruments TLC0838CDWR

Overview

TLC0838CDWR from Texas Instruments is an 8-bit successive-approximation analog-to-digital converter (ADC) with integrated 8-channel multiplexer, serial control interface, and ratiometric operation using a 5-V supply. It delivers ±1 LSB total unadjusted error, 32 µs conversion time at 250 kHz clock, and supports single-ended, differential, and pseudodifferential input configurations for sensor signal digitization in industrial monitoring systems.

For engineers reviewing the TLC0838CDWR datasheet, TLC0838CDWR pinout, TLC0838CDWR application, or TLC0838CDWR equivalent, key selection criteria include its 20-pin SOIC (DW) package, 0°C to 70°C operating range, 0–5 V input range with external reference, serial DI/DO interface timing compatibility with microcontrollers, and functional equivalence to ADC0838 without internal Zener regulator.

Technical Context

The TLC0838CDWR implements a sample-data-comparator architecture with a 9-bit shift register for multiplexer addressing and conversion control. Its serial protocol uses a start bit followed by a 3–4-bit assignment word to select channel and input mode (SGL/DIF/ODD/EVEN), with SARS indicating conversion progress.

Conversion begins after multiplexer settling (one clock period), outputs MSB-first data, and supports LSB-first output via SE pin control. Input configuration is software-defined per cycle, enabling dynamic reassignment of polarity and common-mode reference on the COM pin for pseudodifferential operation across all eight channels.

Key Specifications

Pinout & Package

Package: 20-pin SOIC (DW) - surface-mount, 7.5 mm × 12.8 mm body, 1.27 mm pitch, RoHS-compliant NIPDAU finish, MSL Level-1.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADC0838CCN, TLC0838CDWR offers lower power and true ratiometric flexibility; versus TLC0838CPWR, it provides proven thermal performance in legacy SOIC footprints while maintaining identical signal integrity and timing behavior.

Availability

TLC0838CDWR is available at Aetrix Electronics and suitable for industrial sensor interfaces, automated test equipment, environmental monitoring systems, and motor control feedback requiring stable component supply and long-term manufacturability.

Supply support for TLC0838CDWR 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 delivering analog, embedded processing, and connectivity technologies for industrial, automotive, and consumer applications.

The TLC083x family was designed for cost-sensitive, microprocessor-connected systems needing flexible analog input acquisition with minimal external components and straightforward serial integration.

FAQ

What is the maximum clock frequency supported by the TLC0838CDWR?

The TLC0838CDWR supports a clock frequency range of 10 kHz to 600 kHz per the recommended operating conditions. At 600 kHz, conversion completes in eight clock periods (≈13.3 µs), though timing margins for setup/hold and propagation delay must be verified per layout. The device is characterized for reliable operation up to this limit with proper signal integrity.

Does the TLC0838CDWR require an external reference voltage?

Yes, the TLC0838CDWR requires an external reference voltage applied to the REF pin. It does not include an internal Zener regulator like the ADC0838. This enables true ratiometric operation - for example, tying REF to the same 5-V source powering a resistive sensor bridge - improving measurement accuracy against supply variations.

How does the COM pin function in pseudodifferential mode on the TLC0838CDWR?

In pseudodifferential mode, the COM pin serves as the common negative input for all eight channels. Each CHx input becomes the positive side of a differential pair referenced to COM. This allows digitizing signals biased above ground (e.g., 2.5 V common-mode) without level-shifting, rejecting noise common to all channels while preserving full 8-bit resolution across the selected span.

Can the TLC0838CDWR interface directly with a microcontroller GPIO without level-shifting?

Yes, the TLC0838CDWR's DI, DO, CS, CLK, and SARS pins are TTL- and MOS-compatible with V_IL ≤ 0.8 V and V_IH ≥ 2.0 V at V_CC = 5 V. When interfaced with 5-V microcontrollers (e.g., legacy 8051 or PIC18), no level-shifting is required. For 3.3-V MCUs, verify VIH minimum meets 2.0 V - most modern 3.3-V I/O tolerate 5-V inputs, but consult MCU datasheet.

What is the purpose of the SE pin on the TLC0838CDWR?

The SE (Serial Output Format Select) pin controls data output order: when high, the TLC0838CDWR outputs MSB-first (default); when pulled low before conversion completion, it switches to LSB-first output. This allows firmware alignment with microcontroller shift registers that expect LSB-first data, avoiding software bit-reversal overhead and reducing CPU load during high-speed acquisition.