Texas Instruments TLC1549CP

Overview

TLC1549CP 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 operation from 0°C to 70°C. It interfaces directly with microcontrollers in embedded data acquisition systems requiring ratiometric conversion and noise-isolated analog front-ends.

For engineers reviewing the TLC1549CP datasheet, TLC1549CP pinout, TLC1549CP application, or TLC1549CP equivalent, this device supports fast (≤21 µs) and slow serial transfer modes, differential reference inputs (REF+/REF–), high-impedance analog input (5 MΩ hold, 1 kΩ sampling), and CMOS-compatible 5 V operation - critical for industrial sensor interfacing, battery-powered telemetry, and legacy microcontroller ADC expansion.

Technical Context

The TLC1549CP 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 state controller synchronizes conversion, data latching, and 3-state output enable/disable via CS transitions.

It features differential high-impedance reference inputs enabling ratiometric scaling, supports six defined serial timing modes (10–16 clock cycles), and maintains full 10-bit linearity across its 0°C to 70°C temperature range without external sample-and-hold circuitry. The device is terminal-compatible with TLC549 and TLV1549, preserving design reuse in legacy 8-bit and newer low-voltage systems.

Key Specifications

Pinout & Package

Package: Plastic DIP (P), 8-pin, through-hole. Pin spacing: 0.3 inch (7.62 mm). RoHS-compliant lead finish.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLC1549CP, TLC549CP trades resolution for cost and simplicity in less demanding systems, while TLV1549CPW offers lower voltage operation and power at the expense of 5 V robustness and pinout compatibility - making TLC1549CP the optimal choice for industrial 5 V environments requiring guaranteed 10-bit accuracy and drop-in replacement capability.

Availability

TLC1549CP is available at Aetrix Electronics and suitable for industrial sensor interface, legacy microcontroller ADC expansion, and power supply monitoring requiring stable component supply, long-term obsolescence management, and verified 5 V tolerance.

Supply support for TLC1549CP 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 founded in 1930, specializing in analog, embedded processing, and silicon innovation for industrial, automotive, and communications markets.

The TLC1549 family was designed for cost-sensitive, noise-immune data acquisition in industrial control and instrumentation - emphasizing ease of integration, ratiometric accuracy, and compatibility with legacy 5 V microcontrollers.

FAQ

What is the maximum sampling rate supported by the TLC1549CP?

The TLC1549CP has a guaranteed conversion time of 21 µs, enabling a theoretical maximum sampling rate of approximately 47.6 kSPS. However, actual achievable rate depends on host processor overhead for CS toggling and I/O CLOCK generation. For continuous 10-clock transfers with CS held low (Mode 2), the limiting factor is the 21 µs delay after the 10th I/O CLOCK falling edge before the next conversion can begin. The TLC1549CP datasheet confirms this timing across its 0°C to 70°C operating range.

Does the TLC1549CP require an external clock source?

No, the TLC1549CP includes an on-chip system clock and does not require an external crystal or oscillator. It relies solely on the externally supplied I/O CLOCK signal for serial timing and conversion sequencing. This I/O CLOCK is provided by the host microcontroller and operates up to 2.1 MHz. The internal clock manages sampling, successive approximation, and output register updates - all synchronized to the I/O CLOCK edges. This feature simplifies design and reduces BOM count for the TLC1549CP.

Can the TLC1549CP operate with a 3.3 V supply?

No, the TLC1549CP is specified only for 4.5 V to 5.5 V operation. Its absolute maximum VCC rating is 6.5 V for the C-grade version, and recommended operating conditions explicitly require ≥4.5 V. Attempting 3.3 V operation will result in undefined behavior, failure to meet timing specs (e.g., I/O CLOCK setup/hold), and potential output corruption. For 3.3 V systems, TI's TLV1549CPW is the functionally equivalent 10-bit serial ADC with 2.7–5.5 V support - but it is not pin-compatible with the TLC1549CP.

How does the TLC1549CP handle analog input signals outside the REF+ to REF– range?

The TLC1549CP saturates digitally: input voltages ≥ REF+ produce an output code of 1111111111 (1023 decimal), while inputs ≤ REF– yield 0000000000 (0 decimal). This behavior is guaranteed per the datasheet and applies regardless of whether REF– is grounded or offset. The device remains functional down to 1 V differential reference (REF+ – REF–), though electrical specifications like linearity and error are only guaranteed within the full 2.5 V to VCC+0.2 V reference range. This saturation protects downstream logic and simplifies overvoltage handling in the TLC1549CP.

Is the TLC1549CP pin-compatible with the TLC549CP?

Yes, the TLC1549CP is terminal-compatible with the TLC549CP - meaning identical pinout, signal names, and basic timing relationships. Both use the same 8-pin DIP package and share CS, I/O CLOCK, DATA OUT, REF+, REF–, ANALOG IN, GND, and VCC pin assignments. However, the TLC549CP is an 8-bit device with different resolution, conversion time, and error specs. This compatibility allows hardware reuse in designs upgrading from 8-bit to 10-bit resolution, provided firmware accommodates the extra two bits - a key interoperability feature confirmed in the TLC1549CP datasheet.