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Output Capacitor (µF)

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REF6225, REF6230, REF6233, REF6241, REF6245, REF6250

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SBOS748 – SEPTEMBER 2016

Product Folder Links: REF6225 REF6230 REF6233 REF6241 REF6245 REF6250

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Feature Description (continued)

8.3.4 Stability

The REF62xx family of voltage references are stable with output capacitor values ranging from 10 µF to 47 µF.

At a low output-capacitor value of 10 µF, an effective series resistance (ESR) of 20 mΩ to 100 mΩ is required for

stability; whereas, at a higher value of 47 µF, an ESR of 5 mΩ to 100 mΩ is required. The shaded region in

Figure 52 shows the stable region of operation for the REF62xx devices.

Figure 52. Stable Output Capacitor Range

A capacitor of value 1 µF is required at the FILT pin for stability and noise performance. A low ESR (5 mΩ to 20

mΩ) is easily achieved by increasing the PCB trace length, thus eliminating the need for a discrete resistor.

Higher values of ESR (greater than 20 mΩ, but lesser than 100 mΩ) can be intentionally added to increase the

output bandwidth of the REF62xx. This higher ESR improves the transient performance of the REF62xx, but

worsens noise performance because of increased bandwidth.

8.4 Device Functional Modes

When the EN pin of the REF62xx is pulled high, the device is in active mode. The device must be in active mode

for normal operation.

To place the REF62xx into a shutdown mode, pull the ENABLE pin low. When in shutdown mode, the output of

the device becomes high impedance and the quiescent current of the device reduces to 1 µA (typ). See the

enable pin voltage parameter in the Electrical Characteristics table for logic high and logic low voltage levels.