REF191ESZ-REEL

Overview

The REF191ESZ-REEL is a precision micropower voltage reference from the Analog Devices REF19x series, housed in an 8-lead SOIC package. It provides a fixed nominal output voltage of 2.048 V with an initial accuracy of ±2 mV maximum. The device features a low dropout voltage and consumes a maximum supply current of 45 μA, which reduces to 15 μA in sleep mode. It operates over an extended industrial temperature range of −40°C to +85°C, with typical performance specified up to +125°C.

Feature Summary

• Utilizes patented temperature drift curvature correction circuitry and laser trimming for high stability.
• Includes a dedicated SLEEP pin that allows the output to be turned off while reducing supply current significantly.
• Features short-circuit protection and low dropout voltage characteristics for efficient operation.
• Test pins are provided internally for factory Zener zap trimming but must remain unconnected by the user.

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, F, or G) required for your application, as specifications such as temperature coefficient and line regulation vary between grades. Confirm that the REEL suffix matches your automated assembly needs. Ensure the input voltage remains within the absolute maximum ratings to prevent damage. Check for any recent Product Change Notifications regarding manufacturing site updates.

Selection Notes

Select this component when a stable 2.048 V reference is needed with minimal power consumption. The E grade offers the best temperature coefficient and accuracy, while F and G grades provide lower cost options with relaxed specifications. Consider the low dropout capability if the supply voltage is close to the output voltage. The sleep mode feature is advantageous for battery-operated systems requiring periodic shutdown.

Part Context

This part belongs to the REF19x series of precision band gap voltage references. The series includes various output voltages such as 2.5 V, 3.0 V, 4.5 V, and 5.0 V. All devices in the series share similar architectural features, including micropower operation and low dropout characteristics, making them suitable for a wide range of precision analog applications.

Replacement Considerations

Other members of the REF19x series, such as REF192ESZ or REF193ESZ, offer different nominal output voltages but share the same package and functional interface. Direct substitutes with identical electrical parameters may not exist; verify compatibility based on required output voltage and accuracy grade.

FAQ

What is the function of Pins 1 and 5?

Pins 1 and 5 are Test Pins (TP) reserved for internal factory Zener zap trimming. They should not be connected by the user to maintain accuracy.

How does the SLEEP pin operate?

Applying a low TTL or CMOS level to the SLEEP pin turns off the output and reduces the supply current to less than 15 μA.

Is a capacitor required for proper operation?

Yes, a 1 μF capacitor is required between the output pin and the ground pin for proper operation.