Texas Instruments TLC1542CN

Overview

TLC1542CN 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 TLC1542CN datasheet, TLC1542CN pinout, TLC1542CN application, or TLC1542CN equivalent, key selection considerations include its 21 µs conversion time, 10-bit resolution with self-test modes, 0°C to 70°C operating range, serial timing flexibility (10–16 clock cycles), and compatibility with host processors via SPI-like control without external clock source.

Technical Context

The TLC1542CN implements a switched-capacitor successive-approximation architecture with internal system clock generation, eliminating need for external timing components. Its 14-channel multiplexer selects among 11 analog inputs (A0–A10) or three internal self-test voltages (VREF−, VREF+, mid-scale), using a break-before-make switching scheme to minimize inter-channel crosstalk.

Serial communication uses a 4-wire protocol where ADDRESS accepts 4-bit MSB-first channel address on first four rising edges of I/O CLOCK; sampling begins on fourth falling edge and completes on tenth falling edge, while DATA OUT shifts out previous result's 10 bits synchronously. EOC output signals completion with precise 70–240 ns delay after tenth clock edge.

Key Specifications

Pinout & Package

Package: 20-pin plastic DIP (N package), through-hole mounting, 0.3-inch width, JEDEC MS-001AC compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLC1543CN, the TLC1542CN offers identical pin compatibility and core functionality but lacks auto-increment addressing and has looser zero-scale tolerance; versus ADS7822U, it trades speed and resolution for channel count, DIP form factor, and legacy design continuity.

Availability

TLC1542CN is available at Aetrix Electronics and suitable for industrial sensor monitoring, microcontroller data acquisition, and power supply monitoring requiring stable component supply and long-term commercial-grade availability.

Supply support for TLC1542CN 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 industrial ICs.

The TLC1542CN belongs to TI's legacy 10-bit serial ADC product line, designed specifically for cost-sensitive, medium-speed data acquisition in commercial-grade embedded systems where reliability, ease of interface, and multi-channel integration are critical.

FAQ

What is the maximum sampling rate achievable with the TLC1542CN?

The TLC1542CN has a guaranteed conversion time of 21 µs. In fast mode with 10-clock transfers and CS toggled per cycle, the minimum total cycle time is approximately 21 µs plus interface overhead. At 2.1 MHz I/O CLOCK, this supports up to ~47.6 kSPS for single-channel operation. Multi-channel throughput depends on serial transfer mode and host timing - actual sustained rate for 11-channel scan is ~3–4 kSPS per channel.

Does the TLC1542CN require an external clock source?

No, the TLC1542CN does not require an external clock source. It incorporates an on-chip system clock that drives the successive-approximation conversion process. The I/O CLOCK signal provided by the host controls serial timing only - sampling, conversion, and internal state sequencing are fully self-timed by the device's internal oscillator.

How does the TLC1542CN handle analog input overvoltage conditions?

The TLC1542CN clamps analog inputs to safe levels per absolute maximum ratings: VI must stay within -0.3 V to VCC + 0.3 V. Inputs exceeding REF+ produce all-ones output (1111111111); inputs below REF− yield all-zeros (0000000000). Exceeding ±20 mA peak input current risks permanent damage - external series resistors and clamping diodes are recommended for field-deployed designs.

Can the TLC1542CN be used with a 3.3 V microcontroller?

The TLC1542CN is specified for 4.5 V to 5.5 V supply and logic levels. While its inputs tolerate up to VCC + 0.3 V, driving ADDRESS, CS, and I/O CLOCK from a 3.3 V MCU may violate VIH (min 2.0 V at VCC = 4.5 V) and cause unreliable operation. Level-shifting or using a 5 V-tolerant MCU GPIO is required - the TLC1542CN itself cannot operate from 3.3 V supply.

What self-test functions are available on the TLC1542CN and how are they accessed?

The TLC1542CN provides three internal self-test modes accessed by writing specific 4-bit addresses to the ADDRESS pin: 1011b selects VREF− (outputs 0x200), 1100b selects VREF+ (outputs 0x000), and 1101b selects mid-scale (outputs 0x3FF). These are sampled and converted identically to external channels, enabling verification of reference integrity, gain/offset performance, and ADC functionality without external stimulus.