Texas Instruments ADS1245IDGSR

Overview

ADS1245IDGSR from Texas Instruments is a 24-bit delta-sigma analog-to-digital converter (ADC) with 3 GΩ buffered input impedance, ±2.5 V differential input range, and 15 SPS output rate at 2.4576 MHz clock. It delivers 0.0015% max INL, 158 µA AVDD current at 5 V, and simultaneous 50/60 Hz rejection-ideal for precision portable medical sensors and handheld instrumentation requiring low power and high input impedance.

For engineers reviewing the ADS1245IDGSR datasheet, ADS1245IDGSR pinout, ADS1245IDGSR application, or ADS1245IDGSR equivalent, this page provides verified technical context, real-world timing behavior, validated multi-channel synchronization capability, confirmed Sleep mode power-down sequence, and exact MSOP-10 package terminal mapping per TI SBAS287A Rev. September 2003.

Technical Context

The ADS1245IDGSR implements a third-order delta-sigma modulator with integrated digital filter that achieves single-cycle settling and full 24-bit resolution without post-processing. Its buffered analog front-end maintains 3 GΩ input impedance at 2.4576 MHz CLK, enabling direct connection to high-impedance sources like thermistors and pH electrodes without external amplification.

Dual-supply operation supports 2.5–5.25 V analog (AVDD) and 1.8–3.6 V digital (DVDD) rails, with independent power supply rejection >100 dB at DC. The two-wire serial interface uses DRDY/DOUT for data-ready indication and MSB-first data output on SCLK rising edges, eliminating need for CS or frame-sync signals.

Key Specifications

Pinout & Package

ADS1245IDGSR is housed in a 10-pin MSOP (DGS) package, 3.0 mm × 3.0 mm × 1.0 mm body height, with exposed thermal pad (not electrically connected). Pin 1 marked by dot; top-view orientation per TI SBAS287A.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-resolution, low-power ADC applications.

Compared with ADS1244IDGSR, ADS1245IDGSR adds critical high-impedance buffering for direct sensor interfacing; compared with ADS1256IPWR, it trades raw speed for ultra-low power and integrated line-noise rejection-making ADS1245IDGSR optimal for battery-powered, precision DC measurements.

Availability

ADS1245IDGSR is available at Aetrix Electronics and suitable for hand-held instrumentation, portable medical equipment, and industrial process control requiring stable component supply, long-term lifecycle support, and traceable sourcing from authorized Texas Instruments distribution channels.

Supply support for ADS1245IDGSR 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 converters and low-power signal chains.

The ADS1245IDGSR belongs to TI's precision delta-sigma ADC product line, engineered specifically for high-resolution, low-power, multi-channel measurement systems in space-constrained portable and industrial applications.

FAQ

What is the maximum analog input voltage range supported by the ADS1245IDGSR?

The ADS1245IDGSR supports a differential input range of ±2.5 V when using a 1.25 V reference (VREFP − VREFN = 1.25 V). Its absolute input voltage limits are GND + 0.1 V to AVDD − 1.25 V per AINP and AINN-exceeding these violates linearity specs. For example, with AVDD = 5 V, valid input spans 0.1 V to 3.75 V on each pin, enabling ±3.65 V differential swing if VREF is scaled accordingly.

How does the ADS1245IDGSR achieve simultaneous 50 Hz and 60 Hz rejection?

The ADS1245IDGSR achieves simultaneous 50 Hz and 60 Hz rejection through its fixed-coefficient digital filter, which places deep notches at both frequencies when the system clock is precisely 2.4576 MHz. This clock frequency sets the filter's fundamental notch spacing, allowing rejection without software configuration or external components-verified in TI SBAS287A Figure 19–20.

Can the ADS1245IDGSR operate from a single 3.3 V supply?

Yes-the ADS1245IDGSR supports single-supply operation: connect AVDD and DVDD together to 3.3 V. Both supplies must remain within their respective ranges (AVDD: 2.5–5.25 V; DVDD: 1.8–3.6 V), so 3.3 V satisfies both. Logic inputs CLK and SCLK accept 5 V levels regardless, and DRDY/DOUT output swings to DVDD, requiring level-shifting only if interfacing to lower-voltage controllers.

What is the purpose of the 25th and 26th SCLK pulses in ADS1245IDGSR operation?

The 25th SCLK pulse forces DRDY/DOUT high after data readout; the falling edge of the 26th SCLK initiates self-calibration. This two-pulse sequence-documented in TI SBAS287A Figure 26-is the defined hardware trigger for on-demand calibration, ensuring offset and gain correction without host MCU intervention or register writes.

Does the ADS1245IDGSR require external clock circuitry, or can it use a microcontroller-generated clock?

The ADS1245IDGSR accepts clock inputs from microcontrollers: TI explicitly cites the MSP430's FLL as capable of generating the required 2.4576 MHz clock from a 32.768 kHz crystal. The CLK input tolerates 5 V logic regardless of DVDD, and exhibits hysteresis-making it robust against MCU GPIO jitter. No external crystal or oscillator is mandatory.