J

A

D

JA

T

T

P

R

T

u

6

PRE

POST

HYST

NOM

| V

V

|

V

10

ppm

V

§

·

u

¨

¸

©

¹

Time (hours)

0

100

200

300

400

500

600

700

800

900 1000

-40

-35

-30

-25

-20

-15

-10

-5

0

5

10

10

REF4132

SNAS794A – JUNE 2020 – REVISED JUNE 2020

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Product Folder Links: REF4132

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Copyright © 2020, Texas Instruments Incorporated

8.2 Long-Term Stability

One of the key parameters of the REF4132 references is long-term stability. Typical characteristic expressed as:

curves shows the typical drift value for the REF4132 is 30 ppm from 0 to 1000 hours. This parameter is

characterized by measuring 32 units at regular intervals for a period of 1000 hours. It is important to understand

that long-term stability is not ensured by design and that the output from the device may shift beyond the typical

30 ppm specification at any time. For systems that require highly stable output voltages over long periods of

time, the designer should consider burning in the devices prior to use to minimize the amount of output drift

exhibited by the reference over time.

Figure 17. Long Term Stability - 1000 hours (VREF)

8.3 Thermal Hysteresis

Thermal hysteresis is measured with the REF4132 soldered to a PCB, similar to a real-world application.

Thermal hysteresis for the device is defined as the change in output voltage after operating the device at 25°C,

cycling the device through the specified temperature range, and returning to 25°C. The PCB was baked at 150°C

for 30 minutes before thermal hysteresis was measured. Hysteresis can be expressed by Equation 1:

where

•

VHYST = thermal hysteresis (in units of ppm)

•

VNOM = the specified output voltage

•

VPRE = output voltage measured at 25°C pre-temperature cycling

•

VPOST = output voltage measured after the device has cycled from 25°C through the specified temperature

range of –40°C to +125°C and returns to 25°C.

(1)

8.4 Power Dissipation

The REF4132 voltage references are capable of source and sink up to 10 mA of load current across the rated

input voltage range. However, when used in applications subject to high ambient temperatures, the input voltage

and load current must be carefully monitored to ensure that the device does not exceeded its maximum power

dissipation rating. The maximum power dissipation of the device can be calculated with Equation 2:

where

•

PD is the device power dissipation

•

TJ is the device junction temperature

•

TA is the ambient temperature

•

RθJA is the package (junction-to-air) thermal resistance

(2)