Rainbow Electronics MAX6508 User Manual

General Description

The MAX6505–MAX6508 temperature switches have dual
logic outputs that assert when the die temperature cross­es their trip thresholds. Trip thresholds are factory pro­grammed to convenient temperatures in 5°C increments.

The MAX6505/MAX6506 have an ALARM output that
asserts when the temperature is above the factory-pro­grammed thresholds (available from -40°C to +125°C).
They also have a WARN output that asserts when the
temperature is several degrees below the ALARM thresh­old. The difference between the ALARM and WARN
thresholds (∆TAW) is pin selectable to +5°C, +10°C,
+20°C, or +30°C. The MAX6505’s logic outputs are open
drain, while the MAX6506’s logic outputs are push-pull.

The MAX6507 has open-drain outputs (OVER, OK), and
the MAX6508 has push-pull outputs (OVER, OK), each
with two factory-programmed threshold temperatures
(TOVER and TUNDER) in the wide range of -40°C to
+125°C. The overtemperature output asserts when the
temperature is above TOVER. When the temperature is in
the desired window (less than TOVER and greater than
TUNDER), OK (OK) asserts.

The MAX6505–MAX6508 are accurate to ±0.5°C (typ),
±5.5°C (max). Operating from a +2.5V to +5.5V supply,
these low-cost devices typically consume 30µA supply
current and require no external components for setting
trip points. The MAX6505–MAX6508 are available in a 6­pin SOT23 package.

________________________Applications

µP Temperature Monitoring in High-Speed
Computers

Temperature Control

Temperature Alarms

Fan Control

Features

♦ ±0.5°C (typ) Threshold Accuracy Over Full

Temperature Range

♦ No External Components Required
♦ Low Cost
♦ 30µA (typ) Supply Current
♦ Factory-Programmed Thresholds from -40°C to

+125°C in 5°C Increments

♦ Open-Drain Outputs (MAX6505/MAX6507),

Push-Pull Outputs (MAX6506/MAX6508)

♦ Pin Selectable +2°C, +10°C Hysteresis

(MAX6507/MAX6508)

♦ Pin Selectable +5°C, +10°C, +20°C, +30°C

T

ALARM

- T

WARN

(MAX6505/MAX6506)

♦ SOT23-6 Package

*To complete the suffix information for the MAX6505/

MAX6506, add P or N for positive or negative trip tempera-
ture, and select an available trip point in degrees centigrade.
For example, the MAX6505UTP055-T describes a MAX6505 in
a SOT23-6 package with a +55°C threshold (Table 3). Contact
the factory for pricing and availability of temperature versions
(minimum order 10,000 pieces).

**To complete the suffix information for MAX6507/MAX6508,

see Table 4.

MAX6505–MAX6508

Dual Trip SOT Temperature Switches

________________________________________________________________ Maxim Integrated Products 1

Pin Configurations

19-1712; Rev 1; 4/00

For free samples and the latest literature, visit www.maxim-ic.com or phone [phone].
For small orders, phone [phone].

Ordering Information

Selector Guide appears at end of data sheet.

Typical Operating Circuits appear at end of data sheet.

PART

MAX6505UT_ _ _ _-T* -40°C to +125°C 6 SOT23-6

MAX6506UT_ _ _ _-T* -40°C to +125°C 6 SOT23-6

MAX6507UT_ _ _ _-T** -40°C to +125°C 6 SOT23-6

MAX6508UT_ _ _ _-T** -40°C to +125°C 6 SOT23-6

TEMP. RANGE

PIN­PACKAGE

TOP VIEW

WARN

16

(WARN)

GND

S1

( ) ARE FOR MAX6506.

MAX6505

2

MAX6506

34

SOT23-6

5 S0

ALARM
(ALARM)

V

CC

OK

16

(OK)

GND

S0

MAX6507

2

MAX6508

34

SOT23-6

OVER
(OVER)

5 N.C.

V

CC

( ) ARE FOR MAX6508.

MAX6505–MAX6508

Dual Trip SOT Temperature Switches

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

ELECTRICAL CHARACTERISTICS

(VCC= +2.5V to +5.5V, R

PULLUP

= 100kΩ (MAX6505/MAX6507 only), TA= -40°C to +125°C, unless otherwise noted. Typical values

are at T

A

= +25°C and VCC= +5V, unless otherwise noted.) (Note 1)

Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.

Supply Voltage (VCCto GND) ..................................-0.3V to +6V

S1, S0 to GND ............................................-0.3V to (V

CC

+ 0.3V)

All Other Pins to GND.................................-0.3V to (V

CC

+ 0.3V)

Input/Output Current, All Pins...........................................±20mA

Continuous Power Dissipation (T

A

= +70°C)

6-Pin SOT23 (derate 7.1mW/°C above +70°C)...........571mW

Operating Temperature Range

(T

MIN

to T

MAX

) ..............................................-40°C to +125°C

Thermal Resistance (Θ

JA

)..............................................115°C/W

Storage Temperature Range .............................-65°C to +150°C

Maximum Die Temperature..............................................+150°C

Lead Temperature (soldering, 10s) .................................+300°C

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

Supply Voltage Range V

Supply Current I

Temperature Threshold
Accuracy (Note 2)

Delta Temperature
(T

ALARM

-T

WARNING

)

MAX6505/MAX6506

Temperature Threshold
Hysteresis (Note 3)

CC

S0 = S1 = GND

CC

S0 = GND

-40°C to 0 ° C -5.5 ±0.5 5.5

∆T

0°C to +95 ° C -3.5 ±0.5 3.5

TH

+95°C to +125 ° C -4 ±0.5 4

S1 = GND, S0 = GND 5

∆T

S1 = GND, S0 = V

AW

S1 = VCC, S0 = GND 20

S1 = VCC, S0 = V

ALARM (MAX6505/MAX6506) 2

WARN

T

HYST

(MAX6505/MAX6506)

2.5 5.5 V

CC

CC

MAX6505/
MAX6506

MAX6507/
MAX6508

∆TAW = 5°C or
10°C

∆T

= 20°C or

AW

30°C

40 80

30 60

10

30

5

10

µA

°C

°C

°C

S0 = GND 2

S0 = V

CC

10

0.8 x
V

CCLogic Input Levels (S1, S0)

0.8 x
V

CC

V

CC

-1.5

> 2.5V 0.5

Output Voltage High
(MAX6506/MAX6508)

Output Voltage Low V

OK, OVER
(MAX6507/MAX6508)

V

IH

V

IL

I

V

OH

I

OL

I

I

= 500µA, VCC > 2.5V

SOURCE

= 800µA,VCC > 4.5V

SOURCE

= 3.2mA, V

SINK

= 5mA, V

SINK

CC

> 4.5V 0.5

CC

V

0.8

V

V

MAX6505–MAX6508

Dual Trip SOT Temperature Switches

_______________________________________________________________________________________ 3

Typical Operating Characteristics

(V

CC

= +5V, unless otherwise noted.)

ELECTRICAL CHARACTERISTICS (continued)

(VCC= +2.5V to +5.5V, R

PULLUP

= 100kΩ (MAX6505/MAX6507 only), TA= -40°C to +125°C, unless otherwise noted. Typical values

are at T

A

= +25°C and VCC= +5V, unless otherwise noted.) (Note 1)

Note 1: 100% production tested at T

A

= +25°C. Specifications over temperature limits are guaranteed by design.

Note 2: T

ALARM

, T

UNDER

, and T

OVER

are factory-programmed temperature trip thresholds from -40°C to +125°C in 5°C increments.

Note 3: Temperature threshold hysteresis is defined as the difference from positive-going temperature thresholds minus the nega-

tive-going temperature thresholds.

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

Open-Drain Output Leakage
Current

VCC = 5.5V, V
V

= 5.5V (MAX6505)

WARN

V

= 5.5V, VOK = 5.5V,

CC

= 5.5V (MAX6507)

V

OVER

ALARM

= 5.5V,

1

µA

1

SUPPLY CURRENT

vs. TEMPERATURE

50

VCC = +5V

= 100kΩ

R

PULLUP

45

40

35

30

SUPPLY CURRENT (µA)

25

20

-40 -10 5 20-25 35 50 65 80 95 110 125
TEMPERATURE (°C)

MAX6505/8-01

HYSTERESIS vs. TRIP TEMPERATURE

2.5
VCC = +5V

= 100kΩ

R

PULLUP

2.0

1.5

HYSTERESIS (°C)

1.0

0.5

-40 -10 5-25 20 35 50 65 80 95 110 125
TEMPERATURE (°C)

0.1

MAX6505/8-02

0

-0.1

-0.2

-0.3

-0.4

-0.5

TRIP-POINT ERROR (%)

-0.6

-0.7

-0.8

TRIP-POINT ERROR (%)

vs. SUPPLY VOLTAGE

NORMALIZED TO TRIP-POINT
TEMPERATURE AT V

2.5 3.53.0 4.0 4.5 5.0 5.5
SUPPLY VOLTAGE (V)

CC

= +5V

MAX6505/8-03

A

2V/div

B

A: V
B: ALARM VOLTAGE, R

STARTUP AND POWER-DOWN

MAX6505

)

(T < T

TH

100µs/div

PULSE

CC

PULLUP

= 100kΩ

MAX6505/8-04

A

2V/div

B

A: V
B: ALARM VOLTAGE, R

CC

STARTUP DELAY

PULSE

MAX6505

(T > T

TH

100µs/div

PULLUP

)

MAX6505/8-05

= 100kΩ

MAX6505–MAX6508

Dual Trip SOT Temperature Switches

4 _______________________________________________________________________________________

Pin Description

PIN

MAX6505 MAX6506 MAX6507 MAX6508

1-— -— WARN

-— 1-— -— WARN

2 2 2 2 GND Ground

3, 5 3, 5 -— -— S1, S0

NAME FUNCTION

Open-Drain Active-Low Warning Output. WARN goes low
when the die temperature exceeds T
∆T

AW.

Push-Pull Active-High Warning Output. WARN goes high
when the die temperature exceeds T
∆T

AW.

Delta Temperature Select Input. Connect to V
select the difference between T
1 or see Electrical Characteristics).

ALARM

WARN

WARN

and T

= T

= T

CC

WARN

ALARM

ALARM

or GND to

(Table

-

-

-— -— 33S0

4444V

-— -— 5 5 N.C. No Connection. Not internally connected.

-— -— 6-—

-— -— _ 6 OVER

-— -— 1-— OK

-— -— -—

6-— -— -— ALARM

Hysteresis Select Input. Connect to V

for 10°C

CC

hysteresis. Connect to GND for 2°C hysteresis.

CC

OVER

Supply Voltage Input. Bypass VCC to GND with a 0.1µF
ceramic capacitor.

Open-Drain Active-Low Overtemperature Output.

OVER

goes low when the die temperature exceeds the factory­set value of T

OVER

.
Push-Pull Active-High Overtemperature Output. OVER
goes high when the die temperature exceeds the factory-

set value of T

OVER.

Open-Drain Active-High Temperature Sensor Output. OK
goes high impedance when the die temperature is
between the factory-set values of T
When the die temperature is above T
T

, OK goes low.

UNDER

OVER

OVER

and T

or below

UNDER

.

Push-Pull Active-Low Temperature Sensor Output. OK

1

OK

goes low when the die temperature is between the factory­set values of T

OVER

erature is above T

and T

OVER

or below T

. When the die temp-

UNDER

UNDER

, OK goes high.

Open-Drain Active-Low Alarm Output. ALARM goes low
when the die temperature exceeds the factory-set value of

.

T

ALARM

Push-Pull Active-High Alarm Output. ALARM goes high

-— 6-— -— ALARM

when the die temperature exceeds the factory-set value of
T

.

ALARM

MAX6505–MAX6508

Dual Trip SOT Temperature Switches

_______________________________________________________________________________________ 5

_______________Detailed Description

The MAX6505–MAX6508 fully integrated temperature
switches incorporate two temperature-dependent refer­ences and a comparator. One reference exhibits a pos­itive temperature coefficient and the other a negative
temperature coefficient. The temperature at which the
two reference voltages are equal determines the tem­perature trip point. There are two versions, each of
which has two logic outputs.

The MAX6505/MAX6506 have a main trip point (T

ALARM

)

and a lower, “warning” trip point (T

WARN

). When the die
temperature rises above these trip points, the ALARM
and WARN outputs are asserted (Figure 1). The differ­ence between the two trip points (∆TAW) is pin selec­table to +5°C, +10°C, +20°C, or +30°C by connecting
the two control pins (S0 and S1) high or low (Table 1).
MAX6505 has open-drain active-low outputs; MAX6506
has push-pull active-high outputs.

The MAX6507/MAX6508 have two factory-programmed
threshold temperatures (T

OVER

and T

UNDER

) and two
outputs (OK and OVER). One output (OK) asserts
when the temperature is between T

OVER

and T

UNDER

.
The other output (OVER) asserts when the temperature
is above T

OVER

. Table 4 shows the hex codes to deter­mine the part numbers associated with specific values
of T

OVER

and T

UNDER

. The first hex code indicates the

lower trip point (T

UNDER

) and the second indicates the

higher trip point (T

OVER

). For example, a part with T

UN-

DER

= -10°C and T

OVER

= +75°C will have the part
number MAX6508UTA04B (Table 4 and Figure 2).
MAX6507 has open-drain outputs; MAX6508 has push­pull outputs.

Hysteresis Selection

The temperature threshold hysteresis for the ALARM
output of the MAX6505/MAX6506 is 2°C. The hysteresis
for the WARN output depends on the value of ∆TAW. If
∆TAWis 5°C or 10°C (set by S0 and S1), WARN hys-
teresis is 5°C. If ∆TAWis 20°C or 30°C, WARN hystere­sis is 10°C. MAX6507 and MAX6508 have pin-selectable
hysteresis of 2°C or 10°C for both OVER and OK out­puts (Table 2).

Applications Information

Thermal Considerations

The MAX6505–MAX6508 supply current is typically
30µA. When used to drive high-impedance loads, the
devices dissipate negligible power. Therefore, the die
temperature is essentially the same as the package
temperature. The key to accurate temperature monitor­ing is good thermal contact between the MAX6505–
MAX6508 package and the device being monitored. In

some applications, the SOT23-6 packages may be
small enough to fit underneath a socketed micro­processor (µP), allowing the device to monitor the µP’s
temperature directly. Use the monitor’s output to reset
the µP, assert an interrupt, or trigger an external alarm.
Accurate temperature monitoring depends on the ther­mal resistance between the device being monitored
and the MAX6505–MAX6508 die.

The rise in die temperature due to self-heating is given
by the following formula:

∆T

J

= P

DISSIPATION

✕

θ

JA

where P

DISSIPATION

is the power dissipated by the
MAX6505–MAX6508, and θJAis the package’s thermal
resistance. The typical thermal resistance is +115°C/W
for the SOT23-6 package. To limit the effects of self-heat­ing, minimize the output currents. For example, if the
MAX6505 sinks 5mA, the output voltage is guaranteed to
be less than 0.5V. Therefore, an additional 2.5mW of

Figure 1. Temperature Response—MAX6505UTP065 Outputs,
∆T

AW

= 10°C, and WARN Hysteresis ≈ 5°C

Table 1. MAX6505/MAX6506 ∆T

AW

Selection Table

CONTROL PINS DESCRIPTION

∆T

S0 S1

GND GND 5

GND V

V

CC

V

CC

65°C

55°C

WARN

ALARM

CC

GND 20

V

CC

AW =TALARM

HYSTERESIS ≈ 2°C

HYSTERESIS ≈ 5°C

(°C)

10

30

– T

WARN

MAX6505–MAX6508

Dual Trip SOT Temperature Switches

6 _______________________________________________________________________________________

Figure 2. Temperature Response—MAX6507A04B Outputs
with 2°C Hysteresis

Figure 3. Low-Power, High-Reliability, Fail-Safe Temperature
Monitor

Table 2. Hysteresis Selection

power is dissipated within the IC. This corresponds to a
+0.288°C shift in the die temperature in the SOT23-6.

Power Supply and Bypassing

The MAX6505 and MAX6508 operate from a single­supply voltage in the +2.5V to +5.5V range. Connect a

0.1µF capacitor on the supply voltage line close to the
VCCpin for bypassing.

Low-Cost, Fail-Safe Temperature Monitor

The MAX6505/MAX6506 provide two outputs that can be
used for fail-safe temperature applications (Figure 3). For
example, the first output can activate a fan when the die
temperature exceeds a certain preset temperature. The
second output asserts at a higher temperature that could
be caused by a wide variety of destructive fault condi­tions, including latchup, short circuit, and cooling system
failure. This output can be used to initiate such actions
as shutdown of the entire system (see Typical Operating
Circuits).

The high-level integration, low cost, and small size of the
MAX6505–MAX6508 facilitate the use of multiple temper­ature monitors to increase system reliability.

PART

MAX6505
MAX6506

MAX6507
MAX6508

+75°C

TEMPERATURE

°C

-10

OVER

OK

ALARM CONDITIONS WARN CONDITIONS OK, OVER

2°C — 5°C ∆TWA = 5°C or 10°C

——10°C ∆T

-—— — — 2°C S0 = GND

-—— — — 10°C S0 = V

HYSTERESIS ≈ 2°C

-10°C
HYSFERESIS ≈ 2

TYPICAL THRESHOLD HYSTERESIS

= 20°C or 30°C

WA

°C

*

S1

S0

*∆TAW = T

ALARM

- T

WARN

IS SET TO +30°C.

+2.5V TO +5.5V

V

CC

MAX6506

GND

ALARM

WARN

—

CC

SYSTEM
SHUTDOWN

FAN CONTROL

MAX6505–MAX6508

Dual Trip SOT Temperature Switches

_______________________________________________________________________________________ 7

Table 3. MAX6505/MAX6506 Suffix and Top Mark Codes

PART SUFFIX

MAX6505 UTN035 -35 AAKK

MAX6505 UTN030 -30 AAKL

MAX6505 UTN025 -25 AAKM

MAX6505 UTN020 -20 AAKN

MAX6505 UTN015 -15 AAKO

MAX6505 UTN010 -10 AAKP

MAX6505 UTN005 -5 AAKQ

MAX6505 UTP000 0 AAKR

MAX6505 UTP005 5 AAKS

MAX6505 UTP010 10 AAKT

MAX6505 UTP015 15 AAKU

MAX6505 UTP020 20 AAKV

MAX6505 UTP025 25 AAKW

MAX6505 UTP030 30 AAKX

MAX6505 UTP035 35 AAKY

MAX6505 UTP040 40 AAKZ

MAX6505 UTP045 45 AALA

MAX6505 UTP050 50 AALB

MAX6505 UTP055 55 AALC

MAX6505 UTP060 60 AALD

MAX6505 UTP065 65 AALE

MAX6505 UTP070 70 AALF

MAX6505 UTP075 75 AALG

MAX6505 UTP080 80 AALH

MAX6505 UTP085 85 AALI

MAX6505 UTP090 90 AALJ

MAX6505 UTP095 95 AALK

MAX6505 UTP100 100 AALL

MAX6505 UTP105 105 AALM

MAX6505 UTP110 110 AALN

MAX6505 UTP115 115 AALO

MAX6505 UTP120 120 AALP

MAX6505 UTP125 125 AALQ

TRIP POINT

(°C)

TOP MARK

PART SUFFIX

MAX6506 UTN035 -35 AALR

MAX6506 UTN030 -30 AALS

MAX6506 UTN025 -25 AALT

MAX6506 UTN020 -20 AALU

MAX6506 UTN015 -15 AALV

MAX6506 UTN010 -10 AALW

MAX6506 UTN005 -5 AALX

MAX6506 UTP000 0 AALY

MAX6506 UTP005 5 AALZ

MAX6506 UTP010 10 AAMA

MAX6506 UTP015 15 AAMB

MAX6506 UTP020 20 AAMC

MAX6506 UTP025 25 AAMD

MAX6506 UTP030 30 AAME

MAX6506 UTP035 35 AAMF

MAX6506 UTP040 40 AAMG

MAX6506 UTP045 45 AAMH

MAX6506 UTP050 50 AAMI

MAX6506 UTP055 55 AAMJ

MAX6506 UTP060 60 AAMK

MAX6506 UTP065 65 AAML

MAX6506 UTP070 70 AAMM

MAX6506 UTP075 75 AAMN

MAX6506 UTP080 80 AAMO

MAX6506 UTP085 85 AAMP

MAX6506 UTP090 90 AAMQ

MAX6506 UTP095 95 AAMR

MAX6506 UTP100 100 AAMS

MAX6506 UTP105 105 AAMT

MAX6506 UTP110 110 AAMU

MAX6506 UTP115 115 AAMV

MAX6506 UTP120 120 AAMW

MAX6506 UTP125 125 AAMX

TRIP POINT

(°C)

TOP MARK

Temperature-Window Alarm

The MAX6507 and MAX6508 have an output (OK, OK)
that indicates the die temperature is within the selected
temperature window. This output is asserted when
within the window, and deasserted when outside the
window. Additionally, a second digital output indicates
when the die temperature is above the upper set point.
This is useful in systems where operation is optimized
over a predetermined temperature range. The thermal
overrange signal can be used to assert a thermal shut­down, power-up, recalibration, or other temperature­dependent function (Figure 4 and Typical Operating
Circuits).

Chip Information

TRANSISTOR COUNT: 796

PROCESS: BiCMOS

MAX6505–MAX6508

Dual Trip SOT Temperature Switches

8 _______________________________________________________________________________________

Table 4. MAX6507/MAX6508 Trip
Temperature Code

*Two hex codes are used in the suffix. The first indicates the
the low trip temperature and the second indicates the high trip
temperature. For example, the MAX6507UT8255-T has a lower
trip point of -40°C and an upper trip point of +85 °C.

Figure 4. Temperature-Window Alarms

TRIP TEMPERATURE (°C) HEX CODE*

-40 82

-35 87

-30 8C

-25 91

-20 96

-15 9B

-10 A0

-5 A5
000
505

10 0A
15 0F
20 14
25 19
30 1E
35 23
40 28
45 2D
50 32
55 37
60 3C
65 41
70 46
75 4B
80 50
85 55
90 5A

95 5F
100 64
105 69
110 6E
115 73
120 78

125 7D

+2.5V TO +5.5V

V

CC

S0

MAX6508

GND

OVER

OK

OUT OF RANGE

SHUTDOWN

MAX6505–MAX6508

Dual Trip SOT Temperature Switches

_______________________________________________________________________________________ 9

Typical Operating Circuits

PART OUTPUT LOGIC OUTPUT STAGE

TEMPERATURE THRESHOLD

RANGE

MAX6505 ALARM, WARN Open Drain -40°C to +125°C

MAX6506 ALARM, WARN Push-Pull -40°C to +125°C
MAX6507 OVER, OK Open Drain -40°C to +125°C

MAX6508 OVER, OK Push-Pull -40°C to +125°C

Selector Guide

+2.5V TO +5.5V

S0

S1

MAX6505

+2.5V TO +5.5V

S0

V

CC

GND

MAX6508

V

GND

CC

WARN

ALARM

OVER

OK

R1R

+2.5V TO +5.5V

2

V

INT

SHDN

CC

µP

GND

V

FAN

S0

S1

CC

V

CC

MAX6506

GND

WARN

ALARM

INT

V

µP

GND

V

CC

INT

µP

GND

CC

V

FAN

CC

MAX6505–MAX6508

Dual Trip SOT Temperature Switches

10 ______________________________________________________________________________________

Package Information

6LSOT.EPS

MAX6505–MAX6508

Dual Trip SOT Temperature Switches

______________________________________________________________________________________ 11

NOTES

MAX6505–MAX6508

Dual Trip SOT Temperature Switches

Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.

12 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600

© 2000 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.

NOTES