Texas Instruments TLC1542IDW

Overview

TLC1542IDW from Texas Instruments is a 10-bit CMOS successive-approximation analog-to-digital converter (ADC) 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−), ±1 LSB total unadjusted error, and operates from 4.5 V to 5.5 V supply across −40°C to +85°C. It is used in industrial sensor data acquisition systems requiring ratiometric conversion and isolated analog front-ends.

For engineers reviewing the TLC1542IDW datasheet, TLC1542IDW pinout, TLC1542IDW application, or TLC1542IDW equivalent, key selection considerations include its 10-bit resolution, 11-channel analog multiplexing, EOC signaling, 21 µs conversion time, and compatibility with microcontroller SPI-like serial interfaces using address-driven channel selection.

Technical Context

The TLC1542IDW implements a switched-capacitor successive-approximation architecture with internal system clock generation. Its 14-channel multiplexer selects among 11 external analog inputs (A0–A10) or three internal self-test voltages based on a 4-bit serial address shifted in MSB-first on the ADDRESS line.

Conversion timing is tightly coupled to the I/O CLOCK: sampling begins on the fourth falling edge and holds on the tenth falling edge; EOC asserts low after the tenth falling edge and remains low until conversion completes (21 µs typical). The device supports six serial interface timing modes-fast (10-clock) and slow (11–16-clock)-with CS-controlled synchronization and DATA OUT 3-state behavior.

Key Specifications

Pinout & Package

Package: SOIC-20 (DW), 7.5 mm × 12.8 mm body, 0.65 mm pitch, surface-mount.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLC1543IDW, the TLC1542IDW lacks auto-increment addressing but offers identical 11-channel capability and industrial temperature range; versus ADS7822U, it trades resolution and supply flexibility for integrated multiplexing and deterministic EOC signaling-making it optimal for cost-sensitive, multi-sensor industrial nodes.

Availability

TLC1542IDW is available at Aetrix Electronics and suitable for industrial sensor monitoring, automotive body control, and energy metering front-ends requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.

Supply support for TLC1542IDW 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 innovation.

The TLC1542I series belongs to TI's legacy precision ADC product line designed for cost-effective, multi-channel industrial data acquisition where serial interface simplicity, self-test capability, and robust temperature operation are critical.

FAQ

What is the maximum recommended I/O CLOCK frequency for the TLC1542IDW?

The TLC1542IDW supports an I/O CLOCK frequency up to 2.1 MHz under recommended operating conditions (VCC = 4.5 V to 5.5 V, TA = −40°C to +85°C). At this rate, the minimum I/O CLOCK period is 476 ns, with pulse widths ≥190 ns high/low and transition times ≤1 µs. Exceeding 2.1 MHz may violate setup/hold timing and cause data corruption or missed EOC assertion.

Does the TLC1542IDW require an external clock source for conversion?

No, the TLC1542IDW does not require an external clock source for conversion. It incorporates an on-chip system clock that drives the successive-approximation process. The I/O CLOCK signal is used solely for serial interface timing-address loading, data shifting, and sampling control-not for the core ADC conversion clock.

How does the TLC1542IDW handle analog input overvoltage conditions?

The TLC1542IDW converts analog inputs above REF+ to all ones (1111111111) and inputs below REF− to all zeros (0000000000). Absolute maximum ratings limit analog input voltage to −0.3 V to VCC + 0.3 V. Input leakage current remains ≤±1 µA (TLC1542I grade) at rated conditions, but sustained overvoltage risks permanent damage per absolute maximum limits.

Can the TLC1542IDW perform conversions while CS is held continuously low?

Yes, the TLC1542IDW supports continuous CS-low operation in Mode 2 (fast, 10-clock) and Mode 4 (fast, 16-clock), where EOC rising edge initiates each new conversion cycle. In these modes, CS remains low between conversions, reducing GPIO toggling overhead and enabling high-throughput streaming-provided host timing aligns with EOC and I/O CLOCK specifications.

What is the purpose of the three self-test modes in the TLC1542IDW?

The three self-test modes (selected via ADDRESS = 1011, 1100, 1101) apply internal reference voltages-REF−, REF+, and mid-scale (≈(REF+ + REF−)/2)-to the ADC input. These generate expected output codes (0x000, 0x3FF, 0x200) for in-system functional verification, enabling diagnostics without external test equipment or signal injection.