ADR425B Solder Heat Shift

Document created by analog-archivist Employee on Feb 23, 2016Last modified by RobK on Mar 19, 2018
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Question is regarding the Electrical Specifications of the ADR425B (b-grade).

The initial Accuracy of 0.04% (2mV) has a note "initial accuracy does not
include shift due to solder heat effect"

This 'solder heat effect shift' is not specified and does not have a
graph/histogram. It is simply not mentioned anymore.

I have a few boards here where the measured voltage of the Voltage Ref. is
5.0022V , even one 5.0027V.

When I look in the datasheet of a similar type Voltage reference ADR4550, 5V

Can I assume that the ADR425B has a similar 'Solder Heat Shift' error to the


We have started putting the SHR note and typical numbers in the datasheets spec
table since it has become more relevant and popular. It is highly dependent on
the customer’s temperature profile. We have started collecting data using the
JDEC standard profile as shown in page 21 of REF19x datasheet  linked below.

The architecture and process of ADR425 and ADR4550 are very different and I
will not assume that they will have similar SHR performance. But 2mV is a large
shift that this customer is experiencing assuming his temp. profile is similar
to the one outlined in JDEC and REF19x spec. See attached for the data we have
on SHR in our files.

A grade is much less susceptible to B Grade because the parts shift by about
~1mV on average.