REF194ES

Overview

The REF194ES is a discontinued precision micropower low dropout voltage reference from the Analog Devices REF19x series. It provides a fixed nominal output voltage of 4.5 V with an initial accuracy of ±0.04%. The device features a maximum temperature coefficient of 5 ppm/°C and supports a maximum output current of 30 mA while consuming only 45 μA of supply current. It operates within an extended industrial temperature range of -40°C to +85°C and includes short-circuit protection.

Feature Summary

• Utilizes patented temperature drift curvature correction circuitry and laser-trimmed thin-film resistors for high stability.
• Features a dedicated sleep mode pin that reduces supply current to less than 15 μA when activated by logic levels.
• Incorporates internal 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Verify component authenticity through authorized channels as this part is obsolete. Confirm package integrity and pin alignment against the 8-lead SOIC specification. Check for solder heat effect shifts if reflowed, as initial accuracy specifications exclude such thermal history impacts. Ensure replacement strategies account for the discontinuation status.

Selection Notes

Select this component for designs requiring a stable 4.5 V reference with minimal power consumption. Consider the low dropout characteristic for battery-operated systems where supply voltage approaches the output level. Evaluate the need for sleep mode functionality to extend battery life in intermittent use applications.

Part Context

This part belongs to the REF19x series of precision band gap voltage references manufactured by Analog Devices Inc. The series offers various fixed output voltages including 2.048 V, 2.5 V, 3.0 V, 3.3 V, 4.096 V, 4.5 V, 5.0 V, and others. All variants share similar architectural features regarding low power operation and precision trimming techniques.

Replacement Considerations

REF194ESZ is confirmed as a direct substitute for the REF194ES.

FAQ

What is the function of Test Pins 1 and 5 on the REF194ES?

Test Pins 1 and 5 are reserved for in-package Zener zap factory trimming processes. Users should leave these pins unconnected to maintain optimal output accuracy.

How does the REF194ES achieve its low temperature coefficient?

It uses a patented temperature drift curvature correction circuit combined with laser trimming of highly stable thin-film resistors to minimize drift over temperature variations.