Texas Instruments TLC1543QDW

Overview

TLC1543QDW from Texas Instruments is a 10-bit CMOS switched-capacitor successive-approximation analog-to-digital converter with 11 analog input channels, on-chip 14-channel multiplexer, and serial 4-wire interface (CS, I/O CLOCK, ADDRESS, DATA OUT). It features inherent sample-and-hold, differential high-impedance reference inputs (REF+/REF−), end-of-conversion (EOC) output, and operates across −40°C to 125°C for automotive and industrial sensing applications.

For engineers reviewing the TLC1543QDW datasheet, TLC1543QDW pinout, TLC1543QDW application, or TLC1543QDW equivalent, this page delivers verified technical context, exact pin functions, real-world timing behavior (21 µs conversion time, 10–16-clock serial transfer), ratiometric reference support, and validated alternatives for precision data acquisition systems requiring extended temperature operation.

Technical Context

The TLC1543QDW implements a charge-redistribution successive-approximation architecture with binary-weighted capacitor array, enabling 10-bit resolution and ±1 LSB total unadjusted error. Its internal system clock drives sampling (6 I/O CLOCK periods after 4th falling edge) and conversion, with automatic hold initiated on the 10th I/O CLOCK falling edge.

Serial control uses MSB-first 4-bit address loading on ADDRESS during first four rising edges of I/O CLOCK, selecting one of 11 analog inputs (A0–A10) or three self-test voltages. DATA OUT shifts out previous result's 10 bits synchronously, while EOC transitions low on the 10th I/O CLOCK falling edge and returns high when conversion completes.

Key Specifications

Pinout & Package

Package: 20-pin SOIC (DW), body width 7.5 mm, JEDEC MS-013AC, RoHS-compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADS7822U and TLC1549CP, the TLC1543QDW uniquely combines 11-channel capability, −40°C to +125°C qualification, and hardware self-test-making it the only option among the three qualified for AEC-Q100-relevant automotive subsystems and high-reliability industrial controllers.

Availability

TLC1543QDW is available at Aetrix Electronics and suitable for automotive engine management, industrial programmable logic controllers, medical patient monitors, and energy metering systems requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for TLC1543QDW 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 heritage in precision data converters and automotive-grade ICs.

The TLC154x family was designed specifically for high-reliability, multi-channel data acquisition in electrically noisy and thermally demanding environments-targeting automotive, industrial automation, and instrumentation markets.

FAQ

What is the maximum recommended I/O CLOCK frequency for reliable operation of the TLC1543QDW?

The TLC1543QDW supports an I/O CLOCK frequency up to 2.1 MHz under recommended operating conditions (VCC = 4.5–5.5 V, TA = −40°C to +125°C). At this rate, the minimum I/O CLOCK period is 476 ns, with pulse widths ≥190 ns high/low. Exceeding 2.1 MHz may cause timing violations in address capture or data shift-out, especially at temperature extremes. The TLC1543QDW datasheet specifies setup/hold times referenced to this maximum frequency.

Does the TLC1543QDW require an external sample-and-hold circuit?

No, the TLC1543QDW does not require an external sample-and-hold circuit. It incorporates an inherent sample-and-hold function that automatically acquires the analog input voltage during the sampling phase (triggered by the fourth falling edge of I/O CLOCK) and holds it for conversion. This integrated capability eliminates external components and simplifies PCB layout while maintaining ±1 LSB total unadjusted error across its operating temperature range.

How does the TLC1543QDW handle analog inputs outside the REF+ to REF− range?

The TLC1543QDW clamps out-of-range inputs digitally: analog voltages ≥ REF+ convert to 0x3FF (1023, all ones), and voltages ≤ REF− convert to 0x000 (0, all zeros). This behavior is guaranteed across the full −40°C to +125°C range. The device remains functional with reference spans as low as 1 V (REF+ − REF−), though electrical specifications like linearity and total error apply only within the recommended 2.5 V to VCC span.

Can the TLC1543QDW be used with a 3.3-V microcontroller SPI interface?

Yes, the TLC1543QDW can interface with 3.3-V microcontrollers, but level translation is required on CS, I/O CLOCK, and ADDRESS inputs since they are 5-V-tolerant but not 3.3-V–compatible for reliable logic thresholds. DATA OUT is 3.3-V–safe when VCC = 5 V (VOH ≈ 4.9 V min, VOL ≈ 0.4 V max), but EOC and DATA OUT outputs may exceed 3.3-V logic-high limits-use resistor dividers or buffer ICs to ensure safe interfacing without damaging the MCU.

What self-test voltages are available on the TLC1543QDW and how are they selected?

The TLC1543QDW provides three internal self-test voltages: VREF− (code 0x200), VREF+ (code 0x000), and mid-scale (code 0x3FF). These are selected by writing 4-bit ADDRESS values B (1011), C (1100), or D (1101) respectively during the serial address phase. Each test voltage is routed through the same analog path-including multiplexer and sample-and-hold-as external inputs, enabling full signal-chain validation without external stimulus.