Texas Instruments TLC1549IPG4

Overview

TLC1549IPG4 from Texas Instruments is a 10-bit switched-capacitor successive-approximation analog-to-digital converter with integrated sample-and-hold, serial three-wire interface (CS, I/O CLOCK, DATA OUT), ±1 LSB total unadjusted error, on-chip system clock, and differential high-impedance reference inputs (REF+, REF–). It operates across –40°C to 85°C and is used in microcontroller-based data acquisition systems requiring ratiometric conversion and noise-isolated analog front-ends.

For engineers reviewing the TLC1549IPG4 datasheet, TLC1549IPG4 pinout, TLC1549IPG4 application, or TLC1549IPG4 equivalent, this page delivers verified technical context, validated pin functions, confirmed timing modes (including 10- and 16-clock transfers), real-world sampling behavior (sampling starts on third I/O CLOCK↓, holds on tenth), and precise electrical limits (VCC = 4.5–5.5 V, I/O CLOCK ≤ 2.1 MHz).

Technical Context

The TLC1549IPG4 implements a CMOS switched-capacitor SAR architecture with automatic sample-and-hold, where analog input sampling occurs over seven I/O CLOCK periods (from third to tenth falling edge), followed by charge redistribution-based bit determination from MSB to LSB. Its internal system clock eliminates external timing components.

It supports six serial interface timing modes defined by CS state (active-low continuous vs. toggled) and I/O CLOCK count (10, 11–16), with guaranteed 21 µs conversion time and strict setup/hold requirements (e.g., tsu(CS) = 1.425 µs, twH/twL ≥ 190 ns). Reference inputs enable ratiometric operation, and differential REF+/REF– inputs isolate analog circuitry from logic supply noise.

Key Specifications

Pinout & Package

Package: 8-pin plastic DIP (P package), through-hole mounting, JEDEC MS-001BA compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLC1549IPG4, TLC549CP sacrifices industrial temperature range for lower cost, while TLV1549IDR trades through-hole compatibility for SOIC packaging and lower quiescent current-neither is pin-compatible in footprint, but both retain identical serial protocol and functional behavior.

Availability

TLC1549IPG4 is available at Aetrix Electronics and suitable for industrial sensor interfaces, microcontroller data acquisition systems, power supply monitoring circuits, and portable test equipment requiring stable component supply across extended temperature ranges.

Supply support for TLC1549IPG4 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 power management ICs, with decades of legacy in precision data converters.

The TLC1549 family was designed for cost-sensitive, microcontroller-coupled data acquisition in industrial and instrumentation applications-emphasizing simplicity, noise immunity, and drop-in compatibility with earlier TI ADCs.

FAQ

What is the maximum I/O CLOCK frequency supported by the TLC1549IPG4?

The TLC1549IPG4 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 +85°C). Exceeding this limit risks timing violations, including loss of synchronization during 11–16-clock transfers. The device guarantees correct operation only within this spec-no derating or margin is implied beyond 2.1 MHz.

Does the TLC1549IPG4 require an external clock source?

No, the TLC1549IPG4 contains an on-chip system clock and does not require an external clock source. All timing-including sampling, conversion, and serial data shifting-is derived internally and synchronized to the externally supplied I/O CLOCK signal. This eliminates the need for additional crystal oscillators or clock generators in the TLC1549IPG4 system design.

How does the TLC1549IPG4 handle analog input signals outside the REF+ to REF– range?

The TLC1549IPG4 converts analog inputs ≥ REF+ to the full-scale code (1111111111) and inputs ≤ REF– to the zero-scale code (0000000000). Inputs between REF– and REF+ are linearly quantized into 1024 steps. This clamping behavior is inherent to the SAR architecture and requires proper external scaling to avoid saturation in the TLC1549IPG4 application.

What is the purpose of the DATA OUT pin being driven low on the tenth I/O CLOCK falling edge?

On the tenth I/O CLOCK falling edge, the TLC1549IPG4 drives DATA OUT low to ensure that any additional clock pulses beyond ten produce zero-padded LSBs. This guarantees deterministic output behavior during 11–16-clock transfers and prevents undefined logic states on the serial bus-enabling robust communication even when host firmware sends extra clocks in the TLC1549IPG4 interface.

Can the TLC1549IPG4 operate with a 3.3-V supply?

No, the TLC1549IPG4 is not specified for 3.3-V operation. Its recommended VCC range is 4.5 V to 5.5 V, and absolute maximum ratings cap VCC at 6.5 V for the I-grade version. Operating below 4.5 V violates the datasheet's recommended conditions and may cause increased linearity error, timing failures, or output instability in the TLC1549IPG4 circuit.