Texas Instruments REF6225IDGKT

Overview

REF6225IDGKT from Texas Instruments is a high-precision 2.5-V voltage reference with integrated ADC drive buffer, designed to directly drive the REF pin of SAR and delta-sigma ADCs such as ADS8881 and ADS127L01. It delivers ±0.05% initial accuracy, 3 ppm/°C max temperature drift (0°C to +70°C), <50 mΩ output impedance (DC–200 kHz), and enables first-sample precision to 18 bits in burst-mode data acquisition systems.

For engineers reviewing the REF6225IDGKT datasheet, REF6225IDGKT pinout, REF6225IDGKT application, or REF6225IDGKT equivalent, key selection criteria include reference droop performance under dynamic ADC load, low 1/f noise (3 µVPP/V, 0.1 Hz–10 Hz), SNR/THD preservation when driving precision converters, and programmable short-circuit current via SS pin.

Technical Context

The REF6225IDGKT integrates a bandgap core with a low-output-impedance buffer optimized for transient current demands of SAR ADC reference pins-specifically supporting charge injection during capacitor switching at up to 1 MSPS. Its dual-ground architecture (GND_F/GND_S) separates force and sense paths to minimize PCB layout-induced errors.

It features a dedicated FILT pin requiring ≥1 µF capacitor for stability, an SS pin enabling resistor-programmable short-circuit current limit (10.5 mA typical when open), and EN-controlled shutdown with 1 µA quiescent current. Output voltage is fixed at 2.5 V with no external feedback.

Key Specifications

Pinout & Package

REF6225IDGKT is housed in an 8-pin VSSOP package (3.00 mm × 3.00 mm body size), optimized for space-constrained precision analog layouts with thermal and grounding integrity.

Key Features

Applications

Equivalent & Alternatives

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

Compared with REF6225IDGKT, REF6225IDRCT offers identical performance in a thermally superior WSON package, while REF6125AIDGKT trades lower drift for wider temperature coverage-making REF6225IDGKT optimal for cost-sensitive, high-accuracy 0°C–70°C DAQ systems.

Availability

REF6225IDGKT is available at Aetrix Electronics and suitable for ATE testers, precision data acquisition systems, and medical instrumentation requiring stable component supply with guaranteed long-term availability and consistent parametric performance.

Supply support for REF6225IDGKT 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 company specializing in analog and embedded processing technologies, with leadership in precision analog signal chains.

The REF62xx family was engineered specifically to solve dynamic reference droop in high-speed precision ADC systems-targeting burst-mode DAQ, oscilloscopes, and automated test equipment where first-sample fidelity is non-negotiable.

FAQ

What is the maximum load current supported by REF6225IDGKT?

The REF6225IDGKT supports ±4 mA output current (sourcing and sinking). This is sufficient to drive the REF pin of SAR ADCs like ADS8881 and wideband delta-sigma ADCs such as ADS127L01 without external buffering. Exceeding ±4 mA may trigger the programmable short-circuit protection via the SS pin.

How does REF6225IDGKT achieve <1 LSB droop with ADS8881 at 1 MSPS?

REF6225IDGKT achieves <1 LSB droop through its integrated low-output-impedance buffer (<50 mΩ up to 200 kHz) and optimized charge delivery architecture. When paired with ADS8881 at 1 MSPS, this ensures the reference voltage settles within 19.07 µV (1 LSB) during the first conversion cycle-even under worst-case full-scale input conditions.

Can REF6225IDGKT be used with ADCs other than ADS88xx and ADS127xx families?

Yes-REF6225IDGKT is verified to drive the REF pins of ADS88xx SAR ADCs and ADS127xx delta-sigma ADCs, but its 2.5-V output, low noise, and dynamic drive capability also make it suitable for other precision converters requiring a stable, low-impedance 2.5-V reference, including DACs and high-resolution sigma-delta modulators.

What is the purpose of the separate GND_F and GND_S pins on REF6225IDGKT?

GND_F serves as the return path for the buffered output current (OUT_F), while GND_S provides the reference ground for the output sense circuitry (OUT_S). This Kelvin-style separation rejects voltage drops across PCB traces and improves regulation accuracy-especially critical in high-current or noisy layout environments.

Is a capacitor required on the FILT pin of REF6225IDGKT, and what value is recommended?

Yes-a capacitor ≥1 µF must be connected between the FILT pin and GND_F. TI recommends a 1-µF X7R ceramic capacitor placed close to the device. This capacitor stabilizes the internal buffer's feedback loop and prevents oscillation under varying capacitive loads at the OUT_F pin.