Data Sheet

ADR3625

THEORY OF OPERATION

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POWER CYCLE HYSTERESIS

By power cycling large numbers of samples, the power cycle hyste-

resis can be determined. To keep this measurement independent of

other variables and environmental effects, the power cycle testing

was performed using a high precision measurement system, includ-

ing an ultrastable oil bath.

Figure 46 shows the power cycle hysteresis. The units were pow-

ered down for approximately four hours and then powered up.

The ADR3625 does not have any power cycle hysteresis even

after a long power-down period, making these devices suitable

for equipment that must maintain its calibration accuracy between

power cycles.

Figure 46. Power Cycle Hysteresis

HUMIDITY SENSITIVITY

The ADR3625 is packaged in an MSOP. However, moisture

absorption from the air into the package changes the internal

mechanical stresses on the die, causing shifts in the output voltage.

Figure 47 shows the effects of a step change in relative humidity on

the output voltage over time. The humidity chamber is maintained

at an ambient temperature of +25°C, while the relative humidity

undergoes a step change from 30% to 70%. The relative humidity

is maintained at 70% for the duration of the testing. Note that the

output voltage shifts quickly compared to the overall settling time,

following the step change in relative humidity.

Figure 47. Change in Output Voltage vs. Time After Humidity Step (30% to

70% Relative Humidity (RH))