REF194FS

Overview

The REF194FS is a precision micropower low dropout voltage reference from the Analog Devices REF19x series. It provides a nominal output voltage of 4.50 V with an initial accuracy of ±2 mV maximum. The device features a temperature coefficient of 5 ppm/°C maximum and supports an output current of 30 mA while consuming only 45 μA of supply current. It includes a sleep mode that reduces current to 15 μA maximum. The unit operates within a temperature range of −40°C to +85°C and is housed in an 8-lead SOIC package.

Feature Summary

• Utilizes patented temperature drift curvature correction circuitry and laser-trimmed thin-film resistors for high stability.
• Features a dedicated sleep pin that allows the output to be turned off, significantly reducing supply current consumption.
• Incorporates short-circuit protection to safeguard the device during fault conditions.

Applications

• Portable instruments
• ADCs and DACs
• Smart sensors
• Solar powered applications
• Loop-current-powered instruments

Procurement Notes

Verify the specific suffix FS against official documentation to confirm package type and grade availability. Confirm RoHS compliance status and ensure the ordering part number matches the required electrical grade specifications for your design requirements.

Selection Notes

Select this component when a stable 4.50 V reference is needed with minimal power consumption. Consider the low dropout characteristic for battery-operated systems where supply voltage may approach the output level. Ensure the load current does not exceed the 30 mA limit and verify thermal dissipation capabilities within the operating temperature range.

Part Context

The REF194FS belongs to the REF19x series of precision band gap voltage references manufactured by Analog Devices Inc. This series is designed for applications requiring high accuracy and low power consumption. The REF194 variant specifically targets the 4.50 V output requirement within this family.

Replacement Considerations

Direct replacements include other members of the REF19x series such as REF194ESZ or REF194ES, provided they meet the same electrical specifications and package requirements. Verify compatibility with existing PCB footprints and thermal management strategies.

FAQ

What is the function of Test Pins 1 and 5 on the REF194FS?

Test Pins 1 and 5 are reserved for in-package Zener zap trimming used during manufacturing to achieve high accuracy. Users should leave these pins unconnected.

How does the sleep mode operate on the REF194FS?

Sleep mode is enabled by applying a low TTL or CMOS level to the SLEEP pin. This turns off the output and reduces the supply current to less than 15 μA.