Texas Instruments TLC1549IDR

Overview

TLC1549IDR 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), and on-chip system clock. It delivers ±1 LSB total unadjusted error, supports ratiometric conversion via differential reference inputs (REF+, REF–), and operates across –40°C to 85°C for industrial sensor data acquisition.

For engineers reviewing the TLC1549IDR datasheet, TLC1549IDR pinout, TLC1549IDR application, or TLC1549IDR equivalent, this page provides verified technical context, validated pin functions, confirmed operating parameters (21 µs conversion time, 2.1 MHz max I/O CLOCK, 5 V supply), and real-world interface timing modes - all specific to the TLC1549IDR D-package variant.

Technical Context

The TLC1549IDR implements a CMOS switched-capacitor SAR architecture with automatic sample-and-hold triggered on the third falling edge of I/O CLOCK and held after the tenth falling edge. Its differential high-impedance reference inputs (REF+, REF–) enable ratiometric scaling and isolation from supply noise, while the internal system clock eliminates external timing components.

It uses a 10-bit binary-weighted capacitor array and threshold detector for bit-by-bit charge redistribution, delivering full 10-bit resolution without external calibration. The device supports six distinct serial interface timing modes - including fast (≤21 µs data valid) and slow transfers - determined by CS state and I/O CLOCK count (10–16 clocks), with mode-specific MSB output timing.

Key Specifications

Pinout & Package

Package: SOIC-8 (D package), 8-pin small outline integrated circuit with gull-wing leads, JEDEC MS-012AC compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLV1549IDR and ADS7822U, the TLC1549IDR uniquely balances industrial temperature range, guaranteed ±1 LSB error, integrated S/H, and true 3-wire simplicity - making it the preferred choice for robust, low-component-count 10-bit data acquisition in harsh environments.

Availability

TLC1549IDR is available at Aetrix Electronics and suitable for industrial sensor interfaces, embedded data loggers, motor control feedback loops, and power supply monitoring systems requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for TLC1549IDR 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 and industrial-grade ICs.

The TLC1549 family was designed specifically for cost-sensitive, noise-resilient industrial data acquisition - emphasizing simplicity (3-wire interface), reliability (±1 LSB error), and ease of integration (on-chip clock, S/H, differential references).

FAQ

What is the maximum I/O CLOCK frequency supported by the TLC1549IDR?

The TLC1549IDR 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). This limit ensures proper sampling, conversion, and data output timing - exceeding it may cause invalid conversions or data corruption. The TLC1549IDR datasheet specifies pulse width requirements (≥190 ns high/low time) and transition time (≤1 µs) to maintain reliable operation at this maximum rate.

Does the TLC1549IDR require an external clock source?

No, the TLC1549IDR does not require an external clock source. It incorporates an on-chip system clock that drives the internal successive-approximation logic and sample-and-hold timing. The I/O CLOCK signal provided by the host processor serves only as a serial interface timing reference - controlling sampling start, bit shifting, and conversion handoff - not as the core conversion clock.

How does the TLC1549IDR handle analog input signals outside the REF+ to REF– range?

The TLC1549IDR saturates its output for out-of-range inputs: analog voltages ≥ REF+ convert to all ones (1111111111), and voltages ≤ REF– convert to all zeros (0000000000). This behavior is deterministic and documented in the electrical characteristics table. The device remains functional down to 1 V differential reference, though specified accuracy (±1 LSB) applies only within the recommended 2.5 V to VCC+0.2 V range.

Is the TLC1549IDR pin-compatible with the TLC549 or TLV1549?

Yes, the TLC1549IDR is terminal-compatible with the TLC549 and TLV1549 in the same SOIC-8 (D) package - sharing identical pin numbering, functions, and basic timing. However, differences exist in supply voltage range (TLC549: 3 V to 6 V; TLV1549: 2.7 V to 5.5 V), power consumption, and AC performance. Direct substitution requires verification of reference configuration, clock speed, and temperature requirements.

What is the purpose of the NC pins in the FK (ceramic LCC) package, and do they apply to the TLC1549IDR?

The NC (no internal connection) pins described in the FK package diagram do not apply to the TLC1549IDR, which uses the SOIC-8 (D) package. The TLC1549IDR has only eight functional pins (REF+, ANALOG IN, REF–, GND, CS, DATA OUT, I/O CLOCK, VCC) with no NC terminals. Any reference to NC pins in the datasheet pertains exclusively to the FK, JG, or P variants - not the D-package TLC1549IDR.