Texas Instruments TLC3545IDGKR

Overview

TLC3545IDGKR from Texas Instruments is a 14-bit pseudo-differential successive-approximation analog-to-digital converter (SAR ADC) operating from a single 5-V supply. It delivers 200-KSPS sampling rate, ±1 LSB INL/DNL accuracy, and 81.5 dB SINAD at 15 kHz input - enabling high-fidelity signal acquisition in motor control feedback loops and industrial process monitoring circuits.

For engineers reviewing the TLC3545IDGKR datasheet, TLC3545IDGKR pinout, TLC3545IDGKR application, or TLC3545IDGKR equivalent, key selection criteria include its 8-pin VSSOP (DGK) package, SPI/DSP-compatible serial interface with up to 15 MHz SCLK, rail-to-rail pseudo-differential analog input (AIN+ / AIN−), and auto-power-down mode reducing current to 5 µA between conversions.

Technical Context

The TLC3545IDGKR implements a charge-redistribution SAR architecture with an integrated conversion clock oscillator (7.5–12 MHz), achieving 1.67–2.67 µs conversion time. Its pseudo-differential input stage accepts AIN(+) and AIN(−) signals, where AIN(−) tolerates ±0.2 V ripple for ground noise rejection and zero-scale offset cancellation.

Control is exclusively via the CS pin (Pin 1); no FS pin is used - distinguishing it from the TLC3541. Serial output is MSB-first unipolar straight binary (14-bit result in D13–D0), delivered on SDO (Pin 8) synchronized to SCLK (Pin 7), with data valid on falling SCLK edges and updated on rising edges.

Key Specifications

Pinout & Package

Package: 8-pin VSSOP (DGK), 3.0 mm × 3.0 mm body, 0.65 mm pitch, RoHS-compliant NIPDAUAG finish, MSL Level-1.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 14-bit SAR ADC applications.

Compared with ADS7816U and TLC3541IDGKR, the TLC3545IDGKR uniquely provides 14-bit pseudo-differential acquisition in the same 8-pin DGK package - delivering superior noise immunity and offset cancellation without external components, while maintaining full timing and software compatibility within the TLC35xx family.

Availability

TLC3545IDGKR is available at Aetrix Electronics and suitable for motor control feedback, industrial process sensor interface, and ATE system channel digitizer applications requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for TLC3545IDGKR 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 TLC35xx product line was designed specifically for high-performance, low-power, miniature SAR ADC applications in industrial automation, motor control, and test equipment - emphasizing pin compatibility, integrated clocking, and robust serial interfacing.

FAQ

What is the function of Pin 5 (AIN(−)) on the TLC3545IDGKR?

Pin 5 is the inverted analog input terminal for pseudo-differential operation. It accepts a common-mode or offset reference voltage up to ±0.2 V ripple, enabling ground noise rejection and zero-scale offset cancellation. Unlike true differential ADCs, the TLC3545IDGKR does not internally subtract AIN(−) from AIN(+); instead, it uses AIN(−) to stabilize the sampling node and improve common-mode rejection ratio in noisy industrial environments.

Does the TLC3545IDGKR require an external clock source for conversion?

No, the TLC3545IDGKR does not require an external clock for conversion. It integrates a built-in oscillator (7.5–12 MHz) that generates the internal conversion clock, ensuring consistent 1.67–2.67 µs conversion time regardless of SCLK stability. The external SCLK (Pin 7) is used solely for serial data transfer timing, not for the ADC core conversion process.

Can the TLC3545IDGKR be interfaced directly with a TMS320 DSP without level-shifting?

Yes, the TLC3545IDGKR can interface directly with TMS320 DSPs. Its digital I/O operates from a 4.5–5.5 V supply and meets TI's recommended voltage thresholds: VIH ≥ 2.1 V and VIL ≤ 0.8 V at VDD = 5 V. When driven by a 3.3 V DSP, a level shifter is required on CS and SCLK; however, many TMS320 devices support 5 V-tolerant I/O or have configurable drive strength sufficient for direct connection.

What is the purpose of the auto-power-down mode in the TLC3545IDGKR?

The auto-power-down mode reduces the TLC3545IDGKR's supply current from 3.5 mA to 5 µA between conversions, minimizing power consumption in battery-operated or thermally constrained systems. It activates automatically at the end of each conversion cycle and wakes on the next falling edge of CS - eliminating software overhead while preserving fast wake-up (<1 µs) for high-throughput sampling.

How does the serial output format of the TLC3545IDGKR differ from standard SPI conventions?

The TLC3545IDGKR outputs 14-bit unipolar straight binary data (D13–D0) MSB-first on SDO, with data valid on falling SCLK edges and updated on rising edges - matching standard SPI Mode 0 (CPOL=0, CPHA=1). However, it requires exactly 16 SCLK cycles to read all bits, and SDO returns to high-impedance after the 17th SCLK rising edge (or rising CS edge), differing from typical SPI peripherals that release MISO immediately after final bit.