mal shutdown, power-up, recalibration, or other tem-

perature-dependent function.

Low-Cost, Fail-Safe Temperature Monitor

In high-performance/high-reliability applications, multi-

ple temperature monitoring is important. The high-level

integration and low cost of the MAX6509/MAX6510

facilitate the use of multiple temperature monitors to

increase system reliability. Figure 6 shows two

MAX6510s with different temperature thresholds. This

ensures that fault conditions that can overheat the mon-

itored device cause no permanent damage. The first

temperature monitor activates the fan when the die

temperature exceeds +45°C. The second MAX6510

triggers a system shutdown if the die temperature

reaches +75°C. The second temperature monitor’s out-

put asserts when a wide variety of destructive fault con-

ditions occur, including latchups, short circuits, and

cooling-system failures.

Set-Point Resistor

To set the trip-point temperature, connect a resistor

between SET and GND. The resistor’s value is deter-

(see Typical Operating Characteristics) or from the

equations below.

To set the temperature trip point from -40°C to 0°C, use

the following equation:

To set the temperature trip point from 0°C to +125°C,

use the following equation:

where T is the trip temperature in Kelvin.

Resistor-Programmable

SOT Temperature Switches

_______________________________________________________________________________________

7

MAX6509CAUK

MAX6509HAUK

+5V

HYST

SET

HYST

GND

GND

100k

OUT

OUT

OUT OF RANGE

MAX6510HAUT

HYST

100k

100k

30k

OUTSET

GND

+5V

MAX6509CAUT

GND

SET

OUTSET

HYST

OUT

30k

OUT

OUT OF RANGE

OVERTEMP

UNDERTEMP

Figure 5. Temperature-Window Detector

MAX6510HAUT

GND

HYST

+5V

30k

MAX6510HAUT

GND

HYST

SET

OUT

SET

OUT

OUTSET

OUTSET

TEMPERATURE

FAULT

FAN

CONTROL

µP

HEAT

HEAT

55k

Figure 6. Low-Power, High-Reliability, Fail-Safe Temperature

Monitor

Chip Information

TRANSISTOR COUNT: 234