• Calculate the temperature using the formula:

• Verify that the temperature measured is within ±2°C

of the ambient board temperature. Measure the

ambient board temperature using an accurate cali-

brated temperature sensor.

threshold versions) and observe the state change of

the logic output.

• Disconnect OUT from ground and observe that the

logic output reverts to its initial state.

Hysteresis Testing

The MAX6516–MAX6519 can be programmed with 2°C

GND, respectively. Below is a test feature that can be

used to measure the accuracy of the device’s hystere-

sis using a device with a +65°C threshold:

• Power up the device and observe the state of the

digital output.

• Drive the OUT voltage down gradually.

(high to low or low to high).

• Calculate trip temperature (T1) using:

• Calculate trip temperature (T2).

Thermal Considerations

The MAX6516–MAX6519 supply current is typically 22µA.

When used to drive high-impedance loads, the devices

dissipate negligible power. Therefore, the die tempera-

ture is essentially the same as the package temperature.

Accurate temperature monitoring depends on the thermal

resistance between the device being monitored and the

MAX6516–MAX6519 die. Heat flows in and out of plastic

packages, primarily through the leads. Pin 2 of the 5-pin

SOT23 package provides the lowest thermal resistance to

the die. Short, wide copper traces between the

MAX6516–MAX6519 and the object whose temperature

is being monitored ensures heat transfers occur quickly

and reliably. The rise in die temperature due to self-heat-

ing is given by the following formula:

MAX6516–MAX6519, and

of the package.

The typical thermal resistance is 140°C/W for the

5-pin SOT23 package. To limit the effects of self-

heating, minimize the output current. For example, if the

MAX6516–MAX6519 sink 1mA, the open-drain output

voltage is guaranteed to be less than 0.3V. Therefore,

an additional 0.3mW of power is dissipated within the

IC. This corresponds to a 0.042°C shift in the die tem-

perature in the 5-pin SOT23 package.

Chip Information

PROCESS: BiCMOS

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−

1 8015

0 01062

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.

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.

.

Low-Cost, 2.7V to 5.5V, Analog Temperature

Sensor Switches in a SOT23

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