LT1027ECH-5

Voltage Reference Overview

The LT1027ECH-5 is a precision 5V voltage reference from Analog Devices, housed in an 8-lead TO-5 metal can package. It delivers a nominal output of 5.000V with a guaranteed range of 4.995V to 5.005V for the E grade. The device features a maximum temperature coefficient of 3ppm/°C and operates within a commercial temperature range of 0°C to 70°C. It provides line regulation of 6ppm/V and load regulation of 6ppm/mA while sourcing up to 15mA. The unit incorporates a noise reduction pin and utilizes a subsurface Zener process for low drift and stability.

Voltage Reference Feature Summary

• Utilizes proprietary advanced subsurface Zener bipolar process to eliminate noise and stability issues associated with surface breakdown devices.
• Features a dedicated Noise Reduction (NR) pin that allows external filtering to significantly lower wideband output noise.
• Optimized class B NPN/PNP output stage ensures fast transient response and quick recovery from load steps typical of A-to-D converter inputs.
• Includes a VTRIM adjustment pin enabling precise output voltage calibration without affecting the temperature coefficient.

Voltage Reference Applications

• 12-bit to 16-bit A-to-D and D-to-A converter systems
• High-precision digital voltmeters
• Precision current source circuits
• Reference standard applications

Voltage Reference Procurement Notes

Verify the specific grade suffix 'E' corresponds to the required 3ppm/°C temperature coefficient and 4.995V–5.005V output voltage range. Confirm the H package designation matches the 8-lead TO-5 metal can requirement. Ensure the operating environment stays within the specified 0°C to 70°C commercial temperature limits. Check datasheet notes regarding obsolete package status and potential alternate source recommendations if necessary.

Voltage Reference Selection Notes

Select this component when system accuracy demands low drift without the power consumption of heated references. The E grade offers tighter initial accuracy than C or D grades. Consider the TO-5 package for superior thermal and environmental stability compared to plastic variants. Use the NR pin if peak-to-peak noise below 1ppm is critical for the application's signal integrity requirements.

Voltage Reference Part Context

The LT1027 series represents a family of high-performance precision voltage references designed for demanding measurement systems. The E grade specifically targets applications requiring stricter tolerance bounds on output voltage and temperature drift. This part bridges the gap between general-purpose references and expensive heated substrates, offering military-grade performance characteristics in a commercial package configuration.

Voltage Reference Replacement Considerations

LT1027BCN8-5

Voltage Reference FAQ

How does the Noise Reduction pin affect the output impedance?

Connecting a capacitor to the NR pin reduces wideband noise but increases the impedance looking into the pin to approximately 7kΩ. This may increase start-up settling time to several milliseconds, though it does not affect transient response under load.

What is the recommended output capacitor for best settling time?

For best settling time, either no output bypass capacitor or a 4.7µF tantalum unit is recommended. An 0.1µF ceramic capacitor is not recommended as it maximizes output ringing.