Texas Instruments TLC3545IDGK

Overview

TLC3545IDGK from Texas Instruments is a 14-bit, pseudo-differential successive approximation register (SAR) analog-to-digital converter (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, targeting precision measurement in industrial process control and motor control systems.

For engineers reviewing the TLC3545IDGK datasheet, TLC3545IDGK pinout, TLC3545IDGK application, or TLC3545IDGK equivalent, key selection factors include its 8-pin VSSOP (DGK) package, SPI/DSP-compatible serial interface with up to 15 MHz SCLK, rail-to-rail analog input with 500 kHz bandwidth, and auto-power-down mode reducing current to 5 µA.

Technical Context

The TLC3545IDGK implements a charge-redistribution SAR architecture with an integrated oscillator-based conversion clock, enabling fixed 2.67 µs max conversion time. Its pseudo-differential input structure uses AIN(+) and AIN(−) pins, where AIN(−) accepts up to ±0.2 V ripple for ground noise rejection and zero-scale offset cancellation.

Control is exclusively via the CS pin (pin 1), supporting both SPI microcontroller interfaces (CS-driven cycle start) and TMS320 DSP frame sync integration (FS signal applied to CS). Serial output is MSB-first, 14-bit unipolar straight binary, delivered on SDO after CS falling edge with data valid on SCLK falling 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 ADS8325IDGK and TLC3541IDGK, the TLC3545IDGK uniquely balances 14-bit accuracy, 200-KSPS speed, pseudo-differential noise immunity, and self-clocked operation in an 8-pin VSSOP - making it optimal for space-constrained industrial sensing where ground integrity is compromised.

Availability

TLC3545IDGK is available at Aetrix Electronics and suitable for industrial process control, motor control feedback, and automated test equipment requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for TLC3545IDGK 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 family was designed specifically for high-accuracy, low-power, serial-interface ADC applications in harsh industrial environments - emphasizing robust timing, noise resilience, and drop-in upgrade paths across bit resolutions.

FAQ

What is the function of the AIN(−) pin on the TLC3545IDGK?

The AIN(−) pin on the TLC3545IDGK serves as the inverted input for pseudo-differential operation, accepting up to ±0.2 V ripple to enable ground noise rejection and zero-scale offset cancellation. Unlike true differential ADCs, it does not require matched signal pairs; instead, it references AIN(+) against a controlled common-mode point, improving measurement fidelity in electrically noisy industrial settings without demanding external differential drivers. This behavior is intrinsic to the TLC3545IDGK's architecture and confirmed in its functional description and terminal table.

Does the TLC3545IDGK require an external clock source?

No, the TLC3545IDGK does not require an external clock source for conversion. It integrates a built-in oscillator that generates the internal conversion clock, ensuring a guaranteed maximum conversion time of 2.67 µs regardless of host system timing. The external SCLK (up to 15 MHz) is used solely for serial data transfer synchronization - not for core ADC timing - which simplifies system design and improves jitter immunity. This self-timed operation is explicitly documented in the TLC3545IDGK datasheet features and principles of operation sections.

How does the auto-power-down mode work on the TLC3545IDGK?

The TLC3545IDGK enters auto-power-down mode automatically at the end of each conversion cycle, reducing supply current from 3.5 mA to 5 µA. It wakes up on the next falling edge of the CS pin, enabling rapid resumption of sampling with no initialization delay. This feature is hardware-managed and requires no software configuration - it operates transparently during normal SPI or DSP serial communication sequences. The power-down behavior and current values are specified in the electrical characteristics table and confirmed in the "auto-power down and power up" section of the TLC3545IDGK datasheet.

Can the TLC3545IDGK interface directly with a TMS320 DSP serial port?

Yes, the TLC3545IDGK interfaces directly with TMS320 DSP serial ports by connecting the DSP's FS (frame sync) output to the TLC3545IDGK's CS pin. Since the TLC3545IDGK uses CS exclusively for cycle initiation - unlike the TLC3541 which has a dedicated FS pin - this connection provides native frame-aligned sampling without additional logic. The timing relationships (setup/hold, SCLK alignment) are fully compatible per the TLC3545IDGK's timing diagrams and application examples, and this configuration is validated in TI's official interface schematics.

What is the absolute maximum input voltage range for AIN(−) on the TLC3545IDGK?

The absolute maximum input voltage range for AIN(−) on the TLC3545IDGK is −0.2 V to +0.2 V, as specified in the recommended operating conditions table under "Analog input voltage" for AIN(−). This narrow range reflects its role as a pseudo-differential reference node rather than a full-scale signal input. Exceeding ±0.2 V risks violating the device's absolute maximum ratings and may cause measurement error or latch-up. This limit is distinct from the rail-to-rail 0–VDD range of AIN(+), and is a defined operational constraint of the TLC3545IDGK.