Texas Instruments TLC3545IDR

Overview

TLC3545IDR 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, targeting precision data acquisition in industrial motor control and process monitoring systems.

For engineers reviewing the TLC3545IDR datasheet, TLC3545IDR pinout, TLC3545IDR application, or TLC3545IDR equivalent, key selection considerations include its 8-pin SOIC 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 TLC3545IDR implements a charge-redistribution SAR architecture with built-in conversion clock (7.5–12 MHz oscillator), enabling fixed 2.67 µs max conversion time. Its pseudo-differential input pair (AIN(+) and AIN(−)) supports zero-scale offset cancellation and ground noise rejection, with AIN(−) tolerating ±0.2 V ripple.

Control is exclusively via the CS pin (pin 1), supporting both SPI microcontroller interfaces (CPOL = 0, CPHA = 1) and TMS320 DSP frame-sync operation. Serial output is MSB-first unipolar straight binary (14-bit result + 2 don't-care bits), presented on SDO after CS falling edge with data valid on SCLK falling edges.

Key Specifications

Pinout & Package

Package: 8-pin SOIC (D), RoHS-compliant, MSL Level-1, −40°C to +85°C operating temperature.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADS7822U and TLC3541IDR, the TLC3545IDR uniquely delivers 14-bit pseudo-differential acquisition in an 8-pin SOIC, enabling direct connection to noisy industrial sensors without added components - critical for compact, high-reliability measurement front-ends.

Availability

TLC3545IDR is available at Aetrix Electronics and suitable for industrial process control, motor control feedback, and automated test equipment requiring stable component supply and long-term production continuity.

Supply support for TLC3545IDR 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 over 90 years of innovation in precision signal chain solutions.

The TLC35xx family was designed specifically for high-speed, low-power, miniature data acquisition in resource-constrained industrial and test systems - emphasizing pin efficiency, integrated clocking, and robust serial interfacing.

FAQ

What is the maximum sampling rate supported by the TLC3545IDR?

The TLC3545IDR supports a maximum sampling rate of 200 KSPS, achieved with a 15 MHz SCLK and fixed 2.67 µs conversion time. This rate is guaranteed across the full −40°C to +85°C operating temperature range and enables accurate digitization of signals up to 500 kHz (−1 dB full-power bandwidth). The built-in oscillator eliminates dependency on external clock stability for timing consistency.

Does the TLC3545IDR require an external reference voltage?

Yes, the TLC3545IDR requires an external reference voltage applied to the REF pin (pin 2). The reference must be between 4 V and VDD (max 5.5 V), and directly determines full-scale range and absolute accuracy. TI recommends using a low-noise, stable 4.096 V reference to achieve specified 81.5 dB SINAD and ±1 LSB INL performance - the device does not include an internal reference.

How does the pseudo-differential input of the TLC3545IDR differ from true differential input?

The TLC3545IDR uses pseudo-differential input: AIN(+) accepts rail-to-rail signals (0 to VDD), while AIN(−) serves as a dedicated reference node tolerant of ±0.2 V ripple. Unlike true differential ADCs, it does not perform symmetrical subtraction - instead, it rejects common-mode noise by referencing AIN(+) to a stabilized AIN(−) baseline, making it ideal for shunt current sensing and noisy ground environments.

Can the TLC3545IDR interface directly with a TMS320 DSP without additional logic?

Yes, the TLC3545IDR interfaces directly with TMS320 DSPs using the CS pin (pin 1) as the frame sync input - eliminating need for level shifters or glue logic. The device accepts standard DSP serial port timing (CPOL = 0, CPHA = 1), presents MSB-first data on SDO, and requires only three connections: CS (FS), SCLK, and SDO. No FS pin is present on TLC3545IDR, simplifying routing versus TLC3541.

What power-saving features does the TLC3545IDR offer?

The TLC3545IDR features automatic power-down mode that activates at the end of each conversion cycle, reducing supply current from 3.5 mA to 5 µA. Wake-up occurs on the next CS falling edge, with no additional latency - enabling energy-efficient burst-mode sampling in battery-powered instruments. This feature is fully integrated and requires no configuration registers or external control signals.