Texas Instruments TLC1518IDW

Overview

TLC1518IDW from Texas Instruments is a 10-bit, 400 kSPS, 8-channel serial analog-to-digital converter (ADC) with built-in 4-V reference, 8× FIFO, and SPI/DSP-compatible interface. It operates from a single 5-V supply, supports differential/single-ended inputs, and features hardware- and software-controllable power-down modes (1 µA max in auto power-down). Used in industrial data acquisition systems requiring low-power, multi-channel sampling with deterministic timing.

For engineers reviewing the TLC1518IDW datasheet, TLC1518IDW pinout, TLC1518IDW application, or TLC1518IDW equivalent, key selection considerations include its 8-channel multiplexed SAR architecture, programmable sweep sequencing, extended sampling via CSTART, FIFO-triggered interrupt capability, and compatibility with both microcontroller SPI and TMS320 DSP frame-sync interfaces.

Technical Context

The TLC1518IDW implements a charge-redistribution successive approximation register (SAR) ADC with integrated 8-input analog multiplexer and on-chip sample-and-hold. Its conversion clock is derived directly from SCLK (or SCLK/2), enabling precise synchronization with host controllers.

It supports four conversion modes-single-shot, repeat, sweep, and repeat-sweep-with configurable FIFO trigger levels (1/4 to full) and programmable sampling periods (12 or 24 SCLK cycles). The EOC/INT pin functions as either end-of-conversion flag or interrupt output, while CSTART enables asynchronous, hardware-controlled sampling initiation independent of SCLK timing.

Key Specifications

Pinout & Package

Package: 20-pin SOIC (DW) - surface-mount, industry-standard footprint compatible with automated assembly and thermal management up to 85°C ambient.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 10-bit serial ADC applications.

Compared with TLC2558IPW and ADS7822U, the TLC1518IDW uniquely balances 8-channel count, FIFO buffering, CSTART-triggered sampling, and dual SPI/DSP interface-making it optimal for mid-complexity industrial acquisition where deterministic timing and moderate resolution are prioritized over maximum bits or speed.

Availability

TLC1518IDW is available at Aetrix Electronics and suitable for industrial sensor monitoring, motor control feedback, portable data loggers, and DSP-based signal analysis requiring stable component supply and long-term production continuity.

Supply support for TLC1518IDW 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 digital signal solutions for industrial, automotive, and communications markets.

The TLC1518IDW belongs to TI's precision data acquisition product line, designed specifically for cost-sensitive, low-power, multi-channel industrial measurement systems requiring robust serial interfacing and flexible sampling control.

FAQ

What is the maximum sampling rate supported by the TLC1518IDW?

The TLC1518IDW supports a maximum throughput of 400 kSPS under specified conditions (5-V supply, internal reference, 24-SCLK sampling period). This rate assumes full 10-bit accuracy and accounts for conversion time plus serial readout overhead. Actual achievable rate depends on host interface speed, FIFO usage, and selected sampling mode-shorter sampling (12 SCLK) enables higher effective rates in repeat or sweep modes when paired with fast SCLK (up to 20 MHz).

Does the TLC1518IDW require an external reference voltage?

No, the TLC1518IDW includes an internal 4-V reference and operates fully functional without external reference components. REFP and REFM pins can be configured for internal reference use (REFP = 4 V, REFM = GND) or accept an external differential reference. External reference is optional and only needed when custom full-scale range, improved temperature stability, or higher absolute accuracy is required beyond the internal reference's ±1% initial tolerance.

How does the CSTART pin function in the TLC1518IDW?

The CSTART pin provides hardware-controlled, asynchronous sampling initiation for the TLC1518IDW. A falling edge starts the sampling period; a rising edge ends sampling and triggers conversion. This function operates independently of SCLK and CS, allowing precise timing alignment with external events (e.g., PWM edges or sensor excitation pulses). When unused, CSTART must be tied to VCC to prevent floating input conditions.

Can the TLC1518IDW interface directly with a TMS320 DSP?

Yes, the TLC1518IDW supports direct connection to TMS320-series DSPs via its FS (frame sync) input. When FS is active, data is shifted on falling edges of SCLK and output changes on rising edges-matching standard DSP serial port timing. The FS signal resets the internal command counter and enables SDI, eliminating the need to toggle CS between conversions. This enables efficient, low-overhead streaming into DSP DMA buffers without CPU intervention.

What are the key differences between TLC1518IDW and TLC1514IDW?

The TLC1518IDW features 8 analog inputs (A0–A7), while the TLC1514IDW has only 4 (A0–A3). Both share identical core architecture, timing, power specs, and interface logic-but the TLC1518IDW's extended channel count enables broader sensor coverage without external multiplexing. Pinout differs: TLC1518IDW uses all 20 DW-package pins including A4–A7, whereas TLC1514IDW leaves those pins unconnected or repurposed. Command sets also differ, with TLC1518IDW supporting additional channel-select codes (0001b–0111b) for A1–A7.