Low Cost, 2.7 V to 5.5 V, Pin-Selectable

Temperature Switches in SOT-23

ADT6401/ADT6402

Rev. 0

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FEATURES

±0.5°C (typical) threshold accuracy

Pin-selectable trip points from

−45°C to +5°C in 10°C increments (undertemperature)

45°C to 115°C in 10°C increments (overtemperature)

Maximum operating temperature of 125°C

Open-drain output (ADT6401)

Push-pull output (ADT6402)

Pin-selectable hysteresis of 2°C and 10°C

Supply current of 30 μA (typical)

Space-saving, 6-lead SOT-23 package

APPLICATIONS

Medical equipment

Automotive

Cell phones

Hard disk drives

Personal computers

Electronic test equipment

Domestic appliances

Process control

FUNCTIONAL BLOCK DIAGRAM

2ºC/10ºC

4

GND

5

TOVER/TUNDER

6

TRIP POINT AND

HYSTERESIS

DECODING

ADT6401

COMPARATOR

Σ-Δ

TEMPERATURE-TO-

DIGITAL CONVERTER

Figure 1.

GENERAL DESCRIPTION

The ADT6401/ADT6402 are trip point temperature switches

available in a 6-lead SOT-23 package. Each part contains an

internal band gap temperature sensor for local temperature

sensing. When the temperature crosses the trip point setting,

the logic output is activated. The ADT6401 logic output is

active low and open-drain. The ADT6402 logic output is active

high and push-pull. The temperature is digitized to a resolution

of 0.125°C (11-bit). The pin-selectable trip point settings are

10°C apart starting from −45°C to +5°C for undertemperature

switching, and from 45°C to 115°C for overtemperature

switching.

These devices typically consume 30 μA of supply current. Hystere-

sis is pin selectable at 2°C and 10°C. The temperature switch is

specified to operate over the supply range of 2.7 V to 5.5 V.

When the ADT6401/ADT6402 are used for monitoring tempera-

tures from 45°C to 115°C, the logic output pin becomes active

when the temperature goes higher than the selected trip point

temperature.

When the ADT6401/ADT6402 are used for monitoring tempera-

tures from −45°C to +5°C, the logic output pin becomes active

when the temperature goes lower than the selected trip point

temperature.

PRODUCT HIGHLIGHTS

1.

Σ-Δ based temperature measurement gives high accuracy

and noise immunity.

2.

Wide operating temperature range from −55°C to +125°C.

3.

±0.5°C typical accuracy from −45°C to +115°C.

4.

Pin-selectable threshold settings from −45°C to +115°C in

10°C increments.

5.

Supply voltage is 2.7 V to 5.5 V.

6.

Supply current of 30 μA.

7.

Space-saving, 6-lead SOT-23 package.

8.

Pin-selectable temperature hysteresis of 2°C or 10°C.

9.

Temperature resolution of 0.125°C.