Texas Instruments TLC1549ID

Overview

TLC1549ID from Texas Instruments is a 10-bit switched-capacitor successive-approximation analog-to-digital converter with inherent sample-and-hold, ±1 LSB total unadjusted error, on-chip system clock, and three-wire serial interface (CS, I/O CLOCK, DATA OUT). It operates over –40°C to 85°C and supports ratiometric conversion via differential high-impedance reference inputs (REF+, REF–), enabling precision sensor signal digitization in industrial monitoring systems.

For engineers reviewing the TLC1549ID datasheet, TLC1549ID pinout, TLC1549ID application, or TLC1549ID equivalent, this device delivers verified 10-bit resolution, 21 µs conversion time, CMOS-compatible 3-state serial output, and terminal compatibility with TLC549 and TLV1549 - critical for legacy-replacement ADC selection, low-pin-count microcontroller interfacing, and noise-sensitive analog front-end designs.

Technical Context

The TLC1549ID implements a charge-redistribution successive-approximation architecture using binary-weighted capacitors, where sampling begins on the third falling edge of I/O CLOCK and holds on the tenth. Its internal system clock eliminates external timing components, and differential reference inputs (REF+/REF–) enable ratiometric scaling independent of supply voltage variation.

It supports six serial interface timing modes - including fast (≤21 µs post-tenth-clock MSB valid) and slow modes - selectable via CS state (high/low between transfers) and I/O CLOCK count (10–16 cycles). The 3-state DATA OUT is enabled only when CS is low, with automatic high-impedance reversion upon CS high.

Key Specifications

Pinout & Package

Package: SOIC-8 (D package), 8-pin small outline integrated circuit with standard pin spacing and gull-wing leads.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLC1549CP, the TLC1549ID extends operational reliability to –40°C cold starts, while TLV1549ID trades supply voltage flexibility and lower power for reduced linearity margin - making TLC1549ID optimal for industrial 5 V systems demanding proven temperature robustness and consistent ±1 LSB accuracy.

Availability

TLC1549ID is available at Aetrix Electronics and suitable for industrial sensor interfaces, legacy microcontroller ADC upgrades, and noise-sensitive analog front-ends requiring stable component supply across extended temperature ranges.

Supply support for TLC1549ID 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 expertise in precision data converters.

The TLC1549 family was designed for cost-sensitive, space-constrained industrial and embedded systems requiring reliable 10-bit digitization with minimal external components and straightforward serial interfacing.

FAQ

What is the maximum I/O CLOCK frequency supported by the TLC1549ID?

The TLC1549ID 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). 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 cause timing violations or conversion errors.

Does the TLC1549ID require an external clock source?

No, the TLC1549ID includes an on-chip system clock that drives the internal successive-approximation logic. The external I/O CLOCK signal is used solely for serial data synchronization - controlling sampling timing, bit shifting, and interface handshaking - not for core conversion timing.

How does the TLC1549ID handle analog input signals outside the REF+ to REF– range?

The TLC1549ID converts analog inputs ≥ REF+ to all ones (1111111111) and inputs ≤ REF– to all zeros (0000000000). This hard-clamp behavior is defined in the datasheet and applies regardless of whether REF– is grounded; it ensures predictable saturation without damage, provided absolute maximum ratings are observed.

Can the TLC1549ID be used with a 3.3 V microcontroller interface?

The TLC1549ID is specified for VCC = 4.5–5.5 V and has TTL-compatible input thresholds (VIH ≥ 2 V, VIL ≤ 0.8 V), so it can interface with 3.3 V MCUs only if their outputs meet these voltage levels. However, its DATA OUT high-level voltage is VCC–0.1 V (≥4.4 V), requiring level translation to avoid overdriving 3.3 V inputs unless the MCU tolerates 5 V inputs.

What is the purpose of the NC pins in the FK (ceramic LCC) package variant?

The NC (no internal connection) pins in the FK package - such as pins 1, 3, 9–10, 12–13, 15–17, and 19–20 - are physically present but electrically unconnected to die circuitry. They serve mechanical stability and thermal dissipation roles in the ceramic leadless chip carrier, and must remain unconnected in PCB layout to prevent unintended coupling or shorting.