Texas Instruments TLC1542IDWR

Overview

TLC1542IDWR from Texas Instruments is a 10-bit CMOS successive-approximation analog-to-digital converter with 11 analog input channels, on-chip 14-channel multiplexer, inherent sample-and-hold, and serial 4-wire interface (CS, I/O CLOCK, ADDRESS, DATA OUT). It delivers ±1 LSB total unadjusted error, operates from 4.5 V to 5.5 V, and supports ratiometric conversion via differential REF+/REF− inputs - used in industrial sensor signal conditioning and microcontroller-based data acquisition systems.

For engineers reviewing the TLC1542IDWR datasheet, TLC1542IDWR pinout, TLC1542IDWR application, or TLC1542IDWR equivalent, this page provides verified technical context, validated pin functions, real-world timing behavior (21 µs conversion time, 10–16-clock serial transfer), confirmed self-test modes (VREF−, VREF+, full-scale), and precise package mapping to SOIC-20 (DW).

Technical Context

The TLC1542IDWR implements a switched-capacitor SAR architecture with automatic sample-and-hold triggered on the fourth falling edge of I/O CLOCK and held after the tenth falling edge. Its 14-channel multiplexer selects among 11 external analog inputs (A0–A10) or three internal self-test voltages using a 4-bit MSB-first address sequence.

Serial communication uses a synchronous 4-wire protocol: CS enables the interface, ADDRESS latches the channel select, I/O CLOCK controls sampling timing and bit-shift sequencing, and DATA OUT delivers 10-bit results in MSB-first order with EOC signaling completion. The device features differential high-impedance reference inputs and operates with an on-chip system clock - no external oscillator required.

Key Specifications

Pinout & Package

Package: SOIC-20 (DW), 0.300-inch wide body, surface-mount, 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, TLC1542IDWR provides 2× resolution, integrated 11-channel MUX, and industrial temperature rating - making it superior for deterministic multi-sensor acquisition. Compared with TLC1543IDWR, it offers identical mechanical and electrical compatibility with marginally tighter linearity (±0.5 LSB vs ±1 LSB) in C-grade variants, though both meet ±1 LSB spec at I-grade.

Availability

TLC1542IDWR is available at Aetrix Electronics and suitable for industrial sensor monitoring, motor control feedback, and programmable logic controller (PLC) analog input cards requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for TLC1542IDWR 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 and embedded processing technologies, with decades of expertise in precision data converters and industrial-grade ICs.

The TLC1542 series was designed specifically for cost-sensitive, high-reliability industrial data acquisition - emphasizing serial interface simplicity, built-in diagnostics, and robust operation across –40°C to +85°C without external support components.

FAQ

What is the maximum sampling rate achievable with the TLC1542IDWR?

The TLC1542IDWR has a guaranteed conversion time of 21 µs. In fast-mode operation with continuous CS low and 10-clock transfers, the minimum cycle time is determined by I/O CLOCK frequency (up to 2.1 MHz) and conversion latency. This yields a practical maximum sampling rate of approximately 47.6 kSPS - confirmed by TI's timing diagrams and electrical characteristics table under recommended operating conditions.

Does the TLC1542IDWR require an external clock source?

No, the TLC1542IDWR incorporates an on-chip system clock and does not require an external oscillator. All timing is derived from the host-provided I/O CLOCK signal, which controls address latching, sampling window, data shifting, and state transitions. The internal clock synchronizes conversion phases - eliminating BOM cost and layout complexity associated with external timing components.

How does the TLC1542IDWR handle analog input overvoltage conditions?

The TLC1542IDWR clamps analog inputs to the absolute maximum ratings: VI must remain within –0.3 V to VCC + 0.3 V. Inputs exceeding REF+ produce an all-ones code (1111111111); inputs below REF− yield all-zeros (0000000000). Per TI's datasheet, the device remains functional with reference spans as low as 1 V, but electrical specs (e.g., linearity, error) apply only within the recommended 2.5 V to VCC differential range.

Can the TLC1542IDWR perform simultaneous sampling across multiple channels?

No, the TLC1542IDWR uses a single ADC core with a 14-channel multiplexer - it performs sequential sampling, not true simultaneous acquisition. Channel switching is break-before-make to minimize crosstalk, and each conversion requires dedicated I/O CLOCK cycles. For synchronized multi-channel capture, external sample-hold amplifiers or parallel ADCs (e.g., dual-TLC1542IDWR with staggered triggers) are required.

What is the purpose of the EOC pin on the TLC1542IDWR?

The EOC (End-of-Conversion) pin on the TLC1542IDWR is an active-low, open-drain output that transitions low on the tenth falling edge of I/O CLOCK and returns high once conversion completes (~21 µs later). It serves as hardware synchronization for host processors - enabling interrupt-driven data reads, DMA triggering, or precise timing of subsequent channel selections without polling delays.