Texas Instruments TLC2558IPWR

Overview

TLC2558IPWR from Texas Instruments is a 12-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). It is used in industrial data acquisition systems requiring low-power, multi-channel sampling with programmable sweep sequencing.

For engineers reviewing the TLC2558IPWR datasheet, TLC2558IPWR pinout, TLC2558IPWR application, or TLC2558IPWR equivalent, key selection considerations include its 8-channel multiplexing capability, 12-bit SAR architecture with ±1 LSB DNL/INL, 69 dB SNDR at 12 kHz, auto-sweep mode support, and compatibility with both microcontroller SPI and TMS320 DSP frame-sync interfaces.

Technical Context

The TLC2558IPWR implements a successive-approximation register (SAR) ADC using a 2-bit resistor-string DAC and binary-weighted capacitor array for charge redistribution. Conversion clock is derived directly from SCLK (up to 20 MHz), enabling 1.6 µs conversion time. Sampling is configurable as normal (12 or 24 SCLK cycles) or extended via asynchronous CSTART control.

It integrates an 8-input analog multiplexer with break-before-make switching, on-chip 4-V reference (selectable vs external), and a 12-bit configuration register (CFR) that retains settings across power-down states. Four conversion modes - one-shot, repeat, sweep, and repeat-sweep - are controlled via CFR bits D6–D5 and supported by FIFO-triggered interrupt generation.

Key Specifications

Pinout & Package

The TLC2558IPWR is housed in a 20-pin TSSOP (PW) package with 0.65-mm pitch, rated for –40°C to +85°C operation.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 12-bit, multi-channel, serial ADC applications.

Compared with ADS7822U and MCP3208-I/P, the TLC2558IPWR delivers higher throughput (400 kSPS), integrated FIFO and reference, lower power-down current (1 µA), and dual-interface support (SPI/DSP), making it optimal for resource-constrained, multi-channel embedded systems requiring deterministic timing and minimal external components.

Availability

TLC2558IPWR is available at Aetrix Electronics and suitable for industrial sensor monitoring, automated test equipment, portable data loggers, and motor drive current sensing requiring stable component supply and long-term production continuity.

Supply support for TLC2558IPWR 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 power management technologies.

The TLC2558IPWR belongs to TI's precision data acquisition product line, designed specifically for low-power, multi-channel industrial and instrumentation applications demanding high resolution, flexible timing, and robust serial interfacing.

FAQ

What is the maximum sampling rate achievable with the TLC2558IPWR?

The TLC2558IPWR achieves a maximum throughput of 400 kSPS when operated with a 20-MHz SCLK and short sampling period (12 SCLK cycles). This corresponds to a 1.6-µs conversion time per sample. The actual sustained rate depends on host interface overhead, FIFO management, and selected conversion mode - for example, sweep mode with FIFO threshold set to full (8 entries) enables burst acquisition at this peak rate before requiring a read cycle.

Does the TLC2558IPWR require an external reference voltage?

No, the TLC2558IPWR includes an internal 4-V reference that can be selected via the CFR.D11 bit. When internal reference is enabled, REFP and REFM must be decoupled with 10-µF and 0.1-µF capacitors. An external reference may be used for improved accuracy or customized full-scale range, but it is not required for basic operation of the TLC2558IPWR.

How does the CSTART pin function in the TLC2558IPWR?

The CSTART pin provides asynchronous control over sampling timing in the TLC2558IPWR. A high-to-low transition initiates sampling; a low-to-high transition ends sampling and starts conversion. This extended sampling mode operates independently of SCLK and CS, allowing precise control of acquisition window duration - especially useful for high-impedance sources or when SCLK frequency limits normal sampling time. CSTART must be tied to V_CC if unused.

Can the TLC2558IPWR interface directly with a TMS320 DSP?

Yes, the TLC2558IPWR supports direct interfacing with TMS320 DSPs via its FS (frame sync) pin. When FS is active, input data is latched on falling SCLK edges and output data changes on rising SCLK edges - matching standard DSP serial port timing. The CS pin may be tied high and FS used exclusively as the frame synchronization signal, simplifying connection and eliminating the need for additional glue logic in the TLC2558IPWR design.

What are the key differences between the TLC2558IPWR and TLC2554IPWR?

The TLC2558IPWR features 8 analog inputs (A0–A7) versus 4 in the TLC2554IPWR (A0–A3), and supports more sweep sequence options (four 8-channel patterns vs. four 4-channel patterns). Both share identical core specs: 12-bit resolution, 400 kSPS, FIFO, reference options, and power-down modes. Pinout differs - TLC2558IPWR uses 20-pin TSSOP with A4–A7 and CSTART exposed; TLC2554IPWR uses 16-pin packages without those pins. The TLC2558IPWR is not pin-compatible with TLC2554IPWR.