REF62xx High-Precision Voltage References


Texas Instruments offers its REF62xx high-precision voltage references with integrated high-bandwidth buffer
Image of Texas Instruments’ REF62xx High-Precision Voltage ReferencesTexas Instruments’ voltage references in the REF6000 family have an integrated low output impedance buffer. This enables the user to directly drive the reference (REF) pin of precision data converters, while preserving linearity, distortion, and noise performance. Most precision SAR and delta-sigma analog-to-digital converters (ADCs) switch binary-weighted capacitors onto the REF pin during the conversion process. In order to support this dynamic load, the output of the voltage reference must be buffered with a low-output impedance, high-bandwidth buffer. While not limited to driving the REF pin of the ADS88xx family of SAR ADCs and ADS127xx family of delta-sigma ADCs, the REF6000 family devices are well suited for it.

The REF6000 family of is able to maintain an output voltage within 1LSB (18-bit) with minimal droop, even during the first conversion, while driving the REF pin of the ADS8881. This feature is useful in burst-mode, event-triggered, equivalent-time sampling, and variable-sampling-rate data-acquisition systems. The REF62xx variants of the REF6000 family specify a maximum temperature drift of just 3 ppm/°C and initial accuracy of ±0.05% for both the voltage reference and the low output impedance buffer combined.

Excellent temperature drift performance
3 ppm/°C (max.) from 0°C to 70°C
Extremely low noise
Total noise: 5 μVRMS with 47 μF capacitor
1/f noise (0.1 Hz to 10 Hz): 3 μVPP/V
Integrated ADC drive buffer
Low output impedance:
<50 mΩ (0 kHz to 200 kHz)
First sample precise to 18-bits with ADS8881
Enables burst-mode DAQ systems
Low supply current: 820 μA
Low shutdown current: 1 μA
High initial accuracy: ±0.05%
Very-low noise and distortion
SNR: 100.5 dB, THD: -125 dB (ADS8881)
SNR: 106 dB, THD: -120 dB (ADS127L01)
Output current drive: ±4 mA
Programmable short-circuit current
Verified to drive REF pin of ADS88xx family of SAR ADCs and ADS127xx family of wideband ΔΣ ADCs