REF194FSZ

Overview

The REF194FSZ 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 and a temperature coefficient of 5 ppm/°C maximum. The device operates within a supply voltage range of 4.75 V to 15 V, drawing a maximum supply current of 45 μA. It features a high output current capability of 30 mA and includes short-circuit protection. The component is specified for operation over an extended industrial temperature range of −40°C to +85°C.

Feature Summary

• Utilizes patented temperature drift curvature correction circuitry and laser trimming of thin-film resistors to achieve high initial accuracy and low temperature coefficients.
• Features a dedicated sleep mode that reduces supply current to less than 15 μA when enabled by applying a low logic level to the SLEEP pin.
• Incorporates internal short-circuit protection to safeguard the device during output overload conditions.

Applications

• Portable instrumentation
• Analog-to-digital (ADC) and digital-to-analog (DAC) converters
• Smart sensors
• Solar powered applications
• Loop-current-powered instruments

Procurement Notes

Verify the specific electrical grade (E or G) required for your application, as performance specifications such as line regulation and load regulation vary between grades. Confirm package availability, as the datasheet indicates PDIP and TSSOP packages are restricted to the lowest electrical grade, while all grades are available in SOIC. Ensure compatibility with the REF194FSZ ordering suffix requirements.

Selection Notes

Select this component when a stable 4.50 V reference is needed with minimal power consumption. Consider the E grade for tighter line and load regulation specifications compared to the G grade. Evaluate the low dropout voltage characteristics against your minimum supply voltage requirements. Verify that the 30 mA output current meets the load demands of your circuit design.

Part Context

The REF194FSZ belongs to the REF19x series of precision voltage references manufactured by Analog Devices Inc. This family is characterized by micropower operation and low dropout capabilities, designed for applications requiring high stability and accuracy. The series utilizes band gap technology with advanced curvature correction to maintain performance across varying temperatures.

Replacement Considerations

Direct substitutes include other parts within the REF19x series offering different nominal voltages, such as the REF195 for 5.00 V or REF196 for 3.30 V. Cross-reference with other manufacturers' precision voltage references ensuring matching output voltage, accuracy, and package dimensions if physical replacement is necessary.

FAQ

What is the function of Test Pins 1 and 5 on the REF194FSZ?

Test Pins 1 and 5 are factory test points reserved for in-package Zener zap trimming to achieve high output accuracy. Users should leave these pins unconnected.

How does the REF194FSZ enter sleep mode?

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