Texas Instruments ADS8904BRGER

Overview

ADS8904BRGER from Texas Instruments is a 20-bit, 250-kSPS successive-approximation-register (SAR) analog-to-digital converter with integrated reference buffer and low-dropout regulator (LDO), designed for high-precision differential input acquisition across ±VREF range at 2.5 V–5 V reference voltage. It delivers 104.5 dB SNR and –125 dB THD in medical imaging and test equipment where DC accuracy (±1 ppm INL, ±0.2 ppm DNL) and low-latency output are critical.

For engineers reviewing the ADS8904BRGER datasheet, ADS8904BRGER pinout, ADS8904BRGER application, or ADS8904BRGER equivalent, this page provides verified technical context, package mapping to RGE 24-pin VQFN, confirmed SPI/Enhanced-SPI timing at 22 MHz, real-world AC/DC performance limits, and validated alternative options for high-speed precision data acquisition systems.

Technical Context

The ADS8904BRGER implements a charge-redistribution SAR architecture with internal clocking, enabling deterministic 4 µs conversion time and zero-latency output. Its integrated LDO accepts single RVDD supply (3–5.5 V), while the reference buffer supports external 2.5 V–5 V references with <250 µV offset and no droop during burst-mode acquisition.

It features dual digital interface modes: standard 3-wire SPI (up to 70 MHz SCLK) and TI's Enhanced-SPI (22 MHz at 250 kSPS), which embeds parity bits for host-side data validation and reduces clock speed requirements by >68% versus conventional SPI-simplifying FPGA/DSP timing closure and PCB routing.

Key Specifications

Pinout & Package

ADS8904BRGER is housed in a 4 mm × 4 mm, 24-pin VQFN package (RGE) with exposed thermal pad connected to GND. The package supports fine-pitch PCB assembly and efficient heat dissipation (R_θJB = 8.9°C/W).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-speed precision ADC applications.

Compared with ADS8902BRGER and ADS8910BRGER, the ADS8904BRGER uniquely balances 20-bit precision, 250 kSPS throughput, and 14 mW power-making it optimal for portable, thermally constrained, and calibration-critical applications where full 20-bit linearity must be preserved without overspeeding.

Availability

ADS8904BRGER is available at Aetrix Electronics and suitable for test and measurement instrumentation, medical imaging subsystems, and high-precision industrial data acquisition requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for ADS8904BRGER 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 industrial-grade signal chain solutions.

The ADS890xB family-including ADS8904BRGER-is engineered for high-speed, high-accuracy data acquisition in demanding environments, integrating reference buffering, LDO regulation, and Enhanced-SPI to simplify system design while maintaining metrology-grade performance.

FAQ

What is the maximum supported reference voltage for ADS8904BRGER?

The ADS8904BRGER supports an external reference voltage range of 2.5 V to 5 V on the REFIN pin. Operation outside this range violates absolute maximum ratings and may cause permanent damage or degraded INL/SNR performance. At 5 V reference, the device achieves its specified 104.5 dB SNR and ±1 ppm INL across temperature.

Does ADS8904BRGER require external decoupling capacitors?

Yes-ADS8904BRGER requires a 1 µF ceramic capacitor on the DECAP pins for LDO stability and a 10–22 µF capacitor on REFBUFOUT with ≤1.3 Ω series resistance for reference buffer decoupling. Omitting these compromises SNR, increases THD, and risks LDO oscillation or reference droop during burst-mode acquisition.

Can ADS8904BRGER operate with separate analog and digital supplies?

No-ADS8904BRGER uses an integrated LDO powered solely by RVDD (3–5.5 V); DVDD (1.65–5.5 V) supplies only the digital interface. Using separate analog supplies defeats the LDO integration benefit and violates recommended operating conditions. RVDD must supply both analog core and LDO output.

Is ADS8904BRGER pin-compatible with other devices in the ADS890xB family?

Yes-ADS8904BRGER shares identical pinout, package (RGE 24-pin VQFN), and footprint with ADS8900BRGER and ADS8902BRGER. However, timing parameters (e.g., conversion time, SCLK max frequency) and power consumption differ; firmware and layout must be validated per specific variant's datasheet section 5.6–5.7.

What is the purpose of the RVS pin on ADS8904BRGER?

The RVS pin on ADS8904BRGER functions as a ready/strobe indicator: when CS is high, RVS reflects internal ADCST status; when CS is low, RVS timing aligns with Enhanced-SPI data strobes. It enables source-synchronous read timing with FPGAs and eliminates need for polling or fixed delays in high-throughput systems.