Texas Instruments REF6125IDGKR

Overview

REF6125IDGKR from Texas Instruments is a high-precision, 2.5-V voltage reference IC with integrated ADC drive buffer, ±0.05% initial accuracy, 8 ppm/°C max temperature drift (–40°C to +125°C), 5 µV_RMS total noise (with 47-µF capacitor), and <50 mΩ output impedance (DC–200 kHz). It enables first-sample 18-bit precision when driving the REF pin of ADS8881 SAR ADCs in burst-mode data acquisition systems.

For engineers reviewing the REF6125IDGKR datasheet, REF6125IDGKR pinout, REF6125IDGKR application, or REF6125IDGKR equivalent, this page delivers verified specifications, real-world droop performance data, buffer-driven ADC interface behavior, thermal hysteresis metrics, and validated alternatives for precision analog signal chains.

Technical Context

The REF6125IDGKR implements a bandgap-based reference core paired with a low-output-impedance buffer stage optimized for dynamic capacitive loads-specifically the switching REF pin of SAR ADCs like the ADS88xx family. Its architecture suppresses reference droop during the first conversion cycle by maintaining <1 LSB (19.07 µV) droop at 1 MSPS with ADS8881.

It features programmable short-circuit current via the SS pin, dual ground pins (GND_F/GND_S) for force-sense separation, and FILT pin for external stability capacitor (≥1 µF). The buffer operates across –40°C to +125°C with guaranteed 8 ppm/°C drift and 0.05% combined accuracy for both reference and buffer stages.

Key Specifications

Pinout & Package

VSSOP-8 (DGK) package, 3.00 mm × 3.00 mm body size, with exposed thermal pad (not electrically connected).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-precision voltage reference applications.

Compared with REF5025AIDR and ADR4525BRZ, REF6125IDGKR trades marginal noise/drift improvement for integrated buffer functionality-delivering measurable first-sample accuracy gain in SAR ADC systems without added layout complexity or power overhead.

Availability

REF6125IDGKR is available at Aetrix Electronics and suitable for precision data acquisition systems, industrial PLC analog input modules, and medical monitoring equipment requiring stable component supply across extended temperature ranges and multi-year production cycles.

Supply support for REF6125IDGKR 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 voltage references and data converter ecosystems.

The REF61xx product line was designed specifically to solve reference droop in high-speed SAR ADC applications-integrating buffer, force-sense architecture, and robust thermal performance into a single VSSOP-8 package for space-constrained, high-fidelity signal chains.

FAQ

What is the maximum load current supported by REF6125IDGKR?

REF6125IDGKR supports ±4 mA output current (sourcing and sinking) across –40°C to +125°C. This is sufficient to drive the dynamic REF pin load of ADS88xx SAR ADCs and other precision converters without external buffering. At 4 mA, dropout remains ≤600 mV with VIN ≥ 3 V, ensuring reliable operation in 3.3-V and 5-V systems.

How does REF6125IDGKR achieve <1 LSB droop with ADS8881?

REF6125IDGKR achieves <1 LSB droop (19.07 µV) at 1 MSPS with ADS8881 through its integrated low-output-impedance buffer (<50 mΩ, DC–200 kHz) and optimized force-sense architecture. This actively compensates for the instantaneous charge demand when the ADC's internal capacitor array switches onto the REF pin-verified in TI's SBOS747B datasheet Figure 32–34.

Can REF6125IDGKR be used with ADCs other than ADS88xx?

Yes-REF6125IDGKR is verified to drive the REF pins of ADS88xx SAR ADCs and ADS127xx wideband delta-sigma ADCs. Its buffer architecture also supports other precision converters with similar REF pin capacitance and switching behavior, including ADS89xx and selected ADI/LTC SAR devices-but validation with the target ADC's specific REF pin load profile is recommended.

What is the purpose of separate GND_F and GND_S pins on REF6125IDGKR?

GND_F provides the return path for the force output (OUT_F), while GND_S serves as the reference ground for the sense input (OUT_S). This Kelvin connection rejects voltage drop across PCB traces between the reference and ADC, preserving accuracy even with 100-mΩ trace resistance-critical for maintaining ±0.05% performance in noisy industrial layouts.

Does REF6125IDGKR require an external filter capacitor on the FILT pin?

Yes-REF6125IDGKR requires a ≥1 µF capacitor connected between FILT and GND_F for stability and optimal noise performance. Omitting this capacitor risks oscillation and increased broadband noise. TI recommends ceramic X7R or C0G types placed within 2 mm of the FILT pin, as specified in Section 8.1 of the SBOS747B datasheet.