Texas Instruments ADS1253E/2K5

Overview

ADS1253E/2K5 from Texas Instruments is a 24-bit delta-sigma analog-to-digital converter (ADC) with four differential inputs, 20.8kHz maximum data rate, ±15ppm INL, 1.8ppm rms noise, and external reference support (0.5V–5V). It operates from a single +5V supply and targets high-precision measurement in cardiac diagnostics and chromatography systems.

For engineers reviewing the ADS1253E/2K5 datasheet, ADS1253E/2K5 pinout, ADS1253E/2K5 application, or ADS1253E/2K5 equivalent, key selection criteria include effective resolution vs. data rate trade-offs, channel multiplexing timing, sinc5 filter notch placement for 50/60Hz rejection, and SSOP-16 layout compatibility with isolated serial interface requirements.

Technical Context

The ADS1253E/2K5 employs a 4th-order delta-sigma modulator with fixed 64× oversampling ratio and a sinc5 digital filter that requires five full conversions (1920 system clock cycles at 8MHz) to settle. Its modulator clock is derived by dividing the system clock (CLK) by six, enabling precise control of data rate and filter notches via CLK frequency tuning.

Channel selection uses two Schmitt-trigger digital inputs (CHSEL0/CHSEL1) to route among four fully differential analog inputs; each input pair supports bipolar operation up to ±VREF with common-mode rejection exceeding 90dB at 60Hz. The DOUT/DRDY pin serves dual functions-data-ready indication and MSB-first serial output-with timing tightly coupled to CLK and SCLK edges.

Key Specifications

Pinout & Package

ADS1253E/2K5 is housed in a 16-pin SSOP (DBQ) package with 0.65mm pitch, optimized for compact PCB layouts and thermal performance in industrial measurement modules.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar precision delta-sigma ADC applications.

Compared with ADS1253E/2K5, ADS1254IPWT improves supply-domain isolation at identical speed and resolution, while AD7730BRUZ trades raw throughput for on-chip signal conditioning-making ADS1253E/2K5 optimal for high-speed, externally conditioned sensor arrays.

Availability

ADS1253E/2K5 is available at Aetrix Electronics and suitable for cardiac diagnostics equipment, liquid/gas chromatography instruments, and precision process control systems requiring stable component supply with guaranteed long-term manufacturability.

Supply support for ADS1253E/2K5 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 and embedded processing technologies, with decades of expertise in precision data conversion and signal chain solutions.

The ADS1253E/2K5 belongs to TI's high-resolution delta-sigma ADC product line, engineered specifically for demanding industrial and medical measurement applications where noise, linearity, and temporal coherence are critical.

FAQ

What is the maximum data rate achievable with ADS1253E/2K5, and what system clock frequency is required?

The ADS1253E/2K5 achieves a maximum data rate of 20.8kHz when operated with an 8MHz system clock (CLK). This relationship is fixed: data rate = CLK ÷ 384. Lower CLK frequencies proportionally reduce data rate-e.g., 7.3728MHz yields 19.2kHz-enabling precise notch placement for 50Hz or 60Hz interference rejection in the sinc5 filter response.

How does the ADS1253E/2K5 handle channel multiplexing, and what is the minimum settling time between channel changes?

The ADS1253E/2K5 uses CHSEL0 and CHSEL1 pins to select among four differential input channels. After a channel change, internal logic resets the conversion process on the falling edge of CLK, and valid data appears after five full conversions (1920 CLK cycles at 8MHz). This corresponds to ~0.24ms settling time at maximum data rate, enabling effective multiplexed sampling up to ~4kHz per channel.

Can ADS1253E/2K5 operate with a reference voltage below 0.5V, and what impact does VREF have on noise performance?

No-ADS1253E/2K5 specifies a minimum VREF of 0.5V per its absolute ratings and electrical characteristics. Reducing VREF below this threshold risks violating input stage bias conditions and invalidating specifications. Conversely, increasing VREF up to 4.096V lowers rms noise expressed in ppm of full-scale (e.g., 1.8ppm at 4.096V), thereby improving effective resolution without altering absolute noise floor.

What is the function of the DOUT/DRDY pin, and how is it used during normal data readout?

The DOUT/DRDY pin on ADS1253E/2K5 serves dual roles: it pulses LOW to signal valid data (DRDY mode), then shifts out the 24-bit result MSB-first (DOUT mode) upon receiving SCLK edges. Data must be fully clocked out before the next DRDY pulse; incomplete reads leave residual bits on the pin. The device expects SCLK rising edges to latch data, with propagation delays defined in Table III of the datasheet.

Does ADS1253E/2K5 support synchronization across multiple units, and how is it implemented?

Yes-ADS1253E/2K5 supports hardware synchronization by holding SCLK HIGH for 4–20 consecutive DOUT/DRDY cycles. This forces all connected devices into modulator reset; release occurs on the falling edge of SCLK, aligning their conversion start times. Critical for phase-coherent multi-channel acquisition in chromatography or vibration analysis systems where timing skew must be <1 DRDY period.