Texas Instruments TLC1542CDW

Overview

TLC1542CDW 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 TLC1542CDW datasheet, TLC1542CDW pinout, TLC1542CDW application, or TLC1542CDW equivalent, key selection considerations include its 21 µs conversion time, 10-bit resolution with self-test modes, compatibility with TLC542 terminal layout, and operation across 0°C to 70°C ambient temperature range.

Technical Context

The TLC1542CDW implements a switched-capacitor SAR architecture with internal system clock generation, enabling autonomous sampling and conversion without external timing components. Its 4-bit serial address register selects among 11 analog inputs (A0–A10) or three internal self-test voltages (VREF−, VREF+, mid-scale), with break-before-make multiplexing to minimize inter-channel crosstalk.

Serial communication uses a 10- to 16-clock cycle with configurable CS timing modes (fast/slow, continuous/inactive), where the tenth I/O CLOCK falling edge triggers EOC assertion and initiates hold phase. The device features high-impedance REF+ and REF− inputs (10 µA max static current) and differential reference capability supporting ratiometric measurement against supply or isolated references.

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 TLC1543CDW, the TLC1542CDW offers explicit channel addressing flexibility at the cost of added software control; versus ADS7822U, it trades resolution and speed for integrated 11-channel multiplexing and broader supply tolerance.

Availability

TLC1542CDW is available at Aetrix Electronics and suitable for industrial sensor monitoring, microcontroller data acquisition, and power supply monitoring requiring stable component supply across commercial temperature range.

Supply support for TLC1542CDW 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 company headquartered in Dallas, Texas, delivering analog and embedded processing solutions for industrial, automotive, and communications markets.

The TLC1542 series was designed specifically for cost-sensitive, multi-channel data acquisition in microcontroller-based systems requiring serial interface simplicity, self-contained timing, and robust analog front-end performance.

FAQ

What is the maximum recommended clock frequency for the TLC1542CDW I/O CLOCK input?

The TLC1542CDW supports an I/O CLOCK frequency up to 2.1 MHz under recommended operating conditions (VCC = 4.5 V to 5.5 V, TA = 0°C to 70°C). At this rate, the minimum pulse width is 190 ns for both high and low states. Exceeding 2.1 MHz may cause timing violations, incomplete address latching, or invalid conversion results - always verify setup/hold times per Figure 4 and Figure 5 in the SLAS052G datasheet when designing the host interface for TLC1542CDW.

Does the TLC1542CDW require an external crystal or oscillator to operate?

No, the TLC1542CDW does not require an external crystal or oscillator. It incorporates an on-chip system clock generator that drives the successive-approximation logic and internal timing control. The only external timing signal needed is the host-provided I/O CLOCK for serial communication. This internal clock eliminates BOM cost and board space associated with external timing components while ensuring consistent conversion timing across voltage and temperature for TLC1542CDW.

How does the TLC1542CDW handle analog input overvoltage conditions beyond the REF+ and REF− range?

When an analog input exceeds REF+, the TLC1542CDW outputs the maximum code (1111111111 = 1023 decimal); when below REF−, it outputs the minimum code (0000000000 = 0). These saturation behaviors are guaranteed per the datasheet's absolute maximum ratings and electrical characteristics. However, input voltages outside the –0.3 V to VCC + 0.3 V range risk permanent damage - always use clamping diodes or series resistors to protect TLC1542CDW analog inputs in overvoltage-prone environments.

Can the TLC1542CDW perform conversions while the host is not actively clocking the interface?

Yes, the TLC1542CDW can complete conversions autonomously once initiated. After the host presents the 4-bit address and applies the tenth I/O CLOCK falling edge, the device enters conversion mode and asserts EOC low upon completion - independent of further clock activity. During this period, the host may pause or service other tasks. The result remains latched and ready for readout on the next serial transfer, enabling efficient multitasking in resource-constrained systems using TLC1542CDW.

Is the TLC1542CDW pin-compatible with any newer TI ADCs for upgrade paths?

The TLC1542CDW is not pin-compatible with newer TI ADC families such as the ADS78xx or TLV series due to differences in pin count, function allocation, and interface protocol. While the TLC1543CDW shares identical DW-package pinout and electrical behavior, it is a functional variant rather than a successor. For migration, redesign is required: newer devices typically use standard SPI (with separate MOSI/MISO) instead of the proprietary 4-wire interface of TLC1542CDW, and offer enhanced features like internal references or higher resolution at the cost of layout changes.