Texas Instruments TLC0838CDW

Overview

TLC0838CDW from Texas Instruments is an 8-bit successive-approximation analog-to-digital converter (ADC) with integrated 8-channel multiplexer and serial interface. It operates with a single 5-V supply, supports ratiometric or external 5-V reference operation, delivers ±1 LSB total unadjusted error, and achieves 32 µs conversion time at 250 kHz clock frequency. It is used in industrial sensor signal conditioning where compact serial ADCs interface directly to microcontrollers.

For engineers reviewing the TLC0838CDW datasheet, TLC0838CDW pinout, TLC0838CDW application, or TLC0838CDW equivalent, key selection criteria include its 20-pin SOIC (DW) package, software-configurable single-ended/differential/pseudodifferential input modes, 0°C to 70°C operating range, and compatibility with TTL/MOS logic levels for embedded data acquisition systems.

Technical Context

The TLC0838CDW implements a sample-data-comparator architecture with an internal SAR (successive approximation register) and resistive ladder network. Its multiplexer supports eight analog inputs (CH0–CH7) plus COM terminal, enabling pseudodifferential mode where COM serves as common negative reference across all channels.

Serial communication uses a 9-bit shift register: 1 start bit, 3–4 address bits for channel and mode selection, and 8-bit output data (MSB-first by default, LSB-first when SE is asserted low). Conversion is initiated by CS low, synchronized to CLK edges, with SARS indicating active conversion status.

Key Specifications

Pinout & Package

Package: 20-pin SOIC (DW), 7.5 mm × 12.8 mm body, 1.27 mm pitch, RoHS-compliant NIPDAU lead finish, MSL Level-1 (260°C peak reflow).

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLC0838CDW, ADC0838CCN adds internal voltage regulation at the cost of higher quiescent current and fixed reference accuracy, while TLC0838IDW maintains identical electrical performance with enhanced thermal robustness-enabling drop-in replacement in upgraded environmental designs.

Availability

TLC0838CDW is available at Aetrix Electronics and suitable for industrial sensor interfaces, portable data loggers, and test equipment requiring stable component supply with guaranteed long-term availability and traceable sourcing.

Supply support for TLC0838CDW 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 precision data converter expertise.

The TLC0838 series was designed for cost-sensitive, microprocessor-based data acquisition systems needing compact serial ADCs with flexible input configuration and minimal external components.

FAQ

What is the maximum clock frequency supported by the TLC0838CDW?

The TLC0838CDW supports clock frequencies from 10 kHz to 600 kHz. At 600 kHz, conversion time remains fixed at 8 clock cycles (13.3 µs), but timing margins for setup/hold and propagation delay must be verified per Figure 1 and Figure 2 in the datasheet. For guaranteed operation across temperature, TI specifies 250 kHz as the nominal design point yielding 32 µs total conversion time.

Does the TLC0838CDW require an external reference voltage?

No-the TLC0838CDW operates ratiometrically using VCC as the reference when REF is tied to VCC, or accepts an external 5-V reference for improved accuracy. Its input resistance at REF is 1.3–5.9 kΩ, so external buffers may be needed for low-noise, high-impedance reference sources. The device does not include an internal voltage reference or regulator.

How is differential input configured on the TLC0838CDW?

Differential input on the TLC0838CDW is configured by selecting adjacent channel pairs (e.g., CH0/CH1 or CH2/CH3) via the 3–4-bit serial address, then assigning polarity (+/–) to each terminal. The functional block diagram confirms differential mode uses the internal comparator with two analog inputs; polarity selection determines which channel serves as IN+ or IN– in the subtraction.

Can the TLC0838CDW interface directly with a microcontroller GPIO without level shifting?

Yes-the TLC0838CDW inputs (CS, DI, CLK, SE) and outputs (DO, SARS) are fully compatible with TTL and MOS logic levels. With VCC = 5 V, VIH ≥ 2 V and VIL ≤ 0.8 V meet standard 5-V MCU thresholds, and VOH ≥ 2.4 V / VOL ≤ 0.4 V ensure clean signal reception. No level-shifting circuitry is required for direct connection to 5-V microcontrollers.

What is the purpose of the COM pin on the TLC0838CDW?

The COM pin on the TLC0838CDW serves as the common analog reference for pseudodifferential input mode. When enabled, it acts as the shared negative input for all eight channels (CH0–CH7), allowing each channel to be measured relative to a common bias voltage-useful when sensor circuits operate at non-ground reference potentials, such as in isolated or floating systems.