MAX6501UKP055-T - Maxim Integrated Products, Inc.

________________General Description

The MAX6501–MAX6504 low-cost, fully integrated tem-

perature switches assert a logic signal when their die

temperature crosses a factory-programmed threshold.

Operating from a +2.7V to +5.5V supply, these devices

feature two on-chip, temperature-dependent voltage

references and a comparator. They are available with

factory-trimmed temperature trip thresholds from -45°C

to +115°C in 10°C increments, and are accurate to

±0.5°C (typ) or ±6°C (max). These devices require no

external components and typically consume 30µA sup-

ply current. Hysteresis is pin-selectable at +2°C or

+10°C.

The MAX6501/MAX6503 have an active-low, open-drain

output intended to interface with a microprocessor (µP)

reset input. The MAX6502/MAX6504 have an active-

high, push-pull output intended to directly drive fan-

control logic. The MAX6501/MAX6502 are offered with

hot-temperature thresholds (+35°C to +115°C), assert-

ing when the temperature is above the threshold. The

MAX6503/MAX6504 are offered with cold-temperature

thresholds (-45°C to +15°C), asserting when the tem-

perature is below the threshold.

The MAX6501–MAX6504 are offered in eight standard

temperature versions; contact the factory for pricing

and availability of nonstandard temperature versions.

They are available in 5-pin SOT23 and 7-pin TO-220

packages.

____________________________Features

♦±0.5°C (typical) Threshold Accuracy Over

Full Temperature Range

♦No External Components Required

♦Low Cost

♦30µA Supply Current

♦Factory-Programmed Thresholds from

-45°C to +115°C in 10°C Increments

♦Open-Drain Output (MAX6501/MAX6503)

Push-Pull Output (MAX6502/MAX6504)

♦Pin-Selectable +2°C or +10°C Hysteresis

♦SOT23-5 and TO220-7 Packages

MAX6501–MAX6504†

Low-Cost, +2.7V to +5.5V, Micropower

Temperature Switches in SOT23 and TO-220

________________________________________________________________ Maxim Integrated Products 1

19-1280; Rev 2; 11/99

Ordering Information

*These parts are offered in eight standard temperature versions

with a minimum order of 2,500 pieces. To complete the suffix

information, add P or N for positive or negative trip temperature,

and select an available trip point in degrees centigrade. For

example, the MAX6501UKP065-T describes a MAX6501 in a

SOT23-5 package with a +65°C threshold. Contact the factory for

pricing and availability of nonstandard temperature versions (mini-

mum order 10,000 pieces).

________________________Applications

µP Temperature Monitoring in High-Speed

Computers

Temperature Control

Temperature Alarms

Fan Control

Selector Guide and Pin Configurations appear at end of

data sheet.

PART*

MAX6501UK_ _ _ _-T -55°C to +125°C

TEMP. RANGE PIN-PACKAGE

5 SOT23-5

MAX6503UK_ _ _ _-T -55°C to +125°C 5 SOT23-5

MAX6504UK_ _ _ _-T -55°C to +125°C 5 SOT23-5

MAX6502UK_ _ _ _-T -55°C to +125°C 5 SOT23-5

†Patents Pending

For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800.

For small orders, phone 1-800-835-8769.

MAX6501CM_ _ _ _-T -55°C to +125°C 7 TO-220-7

MAX6502CM_ _ _ _-T -55°C to +125°C 7 TO-220-7

MAX6503CM_ _ _ _-T -55°C to +125°C 7 TO-220-7

MAX6504CM_ _ _ _-T -55°C to +125°C 7 TO-220-7

MAX6502

+2.7V TO +5.5V

GND HYST

TOVER µP

INT

GND GND

VCC VCC

Typical Operating Circuit

MAX6501–MAX6504

Low-Cost, +2.7V to +5.5V, Micropower

Temperature Switches in SOT23 and TO-220

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

ELECTRICAL CHARACTERISTICS

(VCC = +2.7V to +5.5V, RPULL-UP = 100kΩ(MAX6501/MAX6503 only), TA= TMIN to TMAX, unless otherwise noted. Typical values are

at TA= +25°C.) (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.

Note 1: 100% production tested at TA= +25°C. Specifications over temperature limits are guaranteed by design.

Note 2: The MAX6501–MAX6504 are available with internal, factory-programmed temperature trip thresholds from -45°C to +115°C

in +10°C increments (see Selector Guide).

Note 3: Guaranteed by design.

Supply Voltage (VCC) ...............................................-0.3V to +7V

TOVER (MAX6501) ...................................................-0.3V to +7V

TOVER (MAX6502).....................................-0.3V to (VCC + 0.3V)

TUNDER (MAX6503) ................................................-0.3V to +7V

TUNDER (MAX6504) ..................................-0.3V to (VCC + 0.3V)

All Other Pins..............................................-0.3V to (VCC + 0.3V)

Input Current (all pins) ........................................................20mA

Output Current (all pins) .....................................................20mA

Continuous Power Dissipation (TA= +70°C)

5-Pin SOT23-5 (derate 7.1mW/°C above +70°C) .........571mW

Operating Temperature Range .........................-55°C to +125°C

Storage Temperature Range .............................-65°C to +165°C

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

-45°C to -25°C

VCC = 2.7V, VTUNDER = 5.5V (MAX6503),

VTOVER = 5.5V (MAX6501)

-15°C to +15°C

HYST = GND

ISOURCE = 500µA, VCC > 2.7V

(MAX6502/MAX6504 only)

ISINK = 1.2mA, VCC > 2.7V

CONDITIONS

-6 ±0.5 6

µA30 85ICC

V2.7 5.5VCC

Supply Voltage Range

Supply Current

nA10

Open-Drain Output Leakage

Current

-4 ±0.5 4

THYST

Temperature Threshold

Hysteresis

0.8 x VCC

0.3

UNITSMIN TYP MAXSYMBOLPARAMETER

+35°C to +65°C

+75°C to +115°C

-4 ±0.5 4 °C

-6 ±0.5 6

∆TTH

Temperature Threshold

Accuracy (Note 2)

0.2 x VCC

VIL

HYST Input Threshold

(Note 3)

0.8 x VCC

VIH

ISINK = 3.2mA, VCC > 4.5V V

0.4

VOL

Output Voltage Low

HYST = VCC 10 °C

ISOURCE = 800µA, VCC > 4.5V

(MAX6502/MAX6504 only) VCC - 1.5

VOH

Output Voltage High

MAX6501–MAX6504

Low-Cost, +2.7V to +5.5V, Micropower

Temperature Switches in SOT23 and TO-220

_______________________________________________________________________________________ 3

-55 5-25 35 65 95 125

SUPPLY CURRENT

vs. TEMPERATURE

MAX6501 TOC01

TEMPERATURE (°C)

SUPPLY CURRENT (µA)

100

200

300

400

500

600

700

800

-55 5-25 35 65 95 125

MAX6502/MAX6504

OUTPUT SOURCE RESISTANCE

vs. TEMPERATURE

MAX6501 TOC02

TEMPERATURE (°C)

OUTPUT SOURCE RESISTANCE (Ω)

VCC = 2.7V

VCC = 5.0V

VCC = 3.3V

100

120

140

160

-55 5-25 35 65 95 125

OUTPUT SINK RESISTANCE

vs. TEMPERATURE

MAX6501 TOC03

TEMPERATURE (°C)

OUTPUT SINK RESISTANCE (Ω)

VCC = 2.7V

VCC = 5.0V

VCC = 3.3V

+15°C/div

+100°C

+25°C

SOT23 THERMAL STEP RESPONSE

IN PERFLUORINATED FLUID

MAX6501 TOC4

5sec/div

MOUNTED ON 0.75in2

OF 2 oz. COPPER

-5 15-25-45 35 55 75 95 115

HYSTERESIS

vs. TRIP TEMPERATURE

MAX6501 TOC8

TRIP TEMPERATURE (°C)

HYSTERESIS (°C)

MAX6503

MAX6504

HYST = VCC

MAX6501

MAX6502

HYST = VCC

MAX6501

MAX6502

HYST = GND

MAX6503

MAX6504

HYST = GND

+12.5°C/div

+100°C

+25°C

SOT23 THERMAL STEP RESPONSE

IN STILL AIR

MAX6501 TOC5

20sec/div

MOUNTED ON 0.75in2

OF 2 oz. COPPER

TRACE A: TOVER VOLTAGE, RPULL-UP = 100kΩ

TRACE B: VCC PULSE DRIVEN FROM 3.3V CMOS LOGIC OUTPUT

MAX6501 START-UP AND POWER-DOWN

(T < TTH)

MAX6501 TOC07

TRACE A: TOVER VOLTAGE, RPULL-UP = 100kΩ

TRACE B: VCC PULSE DRIVEN FROM 3.3V CMOS LOGIC OUTPUT

MAX6501 START-UP DELAY

(T > TTH)

MAX6501 TOC07A

__________________________________________Typical Operating Characteristics

(VCC = +5V, RPULL-UP = 100kΩ(MAX6501/MAX6503), TA= +25°C, unless otherwise noted.)

-5 -4 -3 -2 -1 0 1 2 3 4 5

TRIP THRESHOLD ACCURACY

MAX6501 TOC-A

ACCURACY (°C)

PERCENTAGE OF PARTS SAMPLED (%)

SAMPLE SIZE = 300

MAX6501–MAX6504

Low-Cost, +2.7V to +5.5V, Micropower

Temperature Switches in SOT23 and TO-220

4 _______________________________________________________________________________________

Pin Description

1, 2 1, 2

Ground. Not internally connected. Tie both ground pins togeth-

er close to the chip. Pin 2 provides the lowest thermal resis-

tance to the die.

1, 2

1, 2 GND

3 3 Hysteresis Input. Connect HYST to GND for +2°C hysteresis, or

connect to VCC for +10°C hysteresis.

3 3 HYST

4 4 Supply Input (+2.7V to +5.5V)

5 —

Open-Drain, Active-Low Output. TOVER goes low when the die

temperature exceeds the factory-programmed temperature

threshold. Connect to a 100kΩpull-up resistor. May be pulled

up to a voltage higher than VCC.

— — TOVER

4 4 VCC

— 5

Push-Pull Active-High Output. TOVER goes high when the die tem-

perature exceeds the factory-programmed temperature threshold.

— —

Open-Drain, Active-Low Output. TUNDER goes low when the

die temperature goes below the factory-programmed tempera-

ture threshold. Connect to a 100kΩpull-up resistor. May be

pulled up to a voltage higher than VCC.

5 — TUNDER

— —

Push-Pull Active-High Output. TUNDER goes high when the die tem-

perature falls below the factory-programmed temperature threshold.

— 5 TUNDER

— — TOVER

MAX6502MAX6501 MAX6503 MAX6504

NAME FUNCTION

________________General Description

The MAX6501–MAX6504 fully integrated temperature

switches incorporate two temperature-dependent refer-

ences and a comparator. One reference exhibits a pos-

itive temperature coefficient and the other a negative

temperature coefficient (Figure 1). The temperature at

which the two reference voltages are equal determines

the temperature trip point. Pin-selectable +2°C or

+10°C hysteresis keeps the output from oscillating

when the die temperature approaches the threshold

temperature. The MAX6501/MAX6503 have an active-

low, open-drain output structure that can only sink cur-

rent. The MAX6502/MAX6504 have an active-high,

push-pull output structure that can sink or source cur-

rent. The internal power-on reset circuit guarantees the

output is at TTH = +25°C state at start-up for 50µs.

The MAX6501–MAX6504 are available with factory-

preset temperature thresholds from -45°C to +115°C in

10°C increments. Table 1 lists the available temperature

threshold ranges. The MAX6501/MAX6503 outputs are

intended to interface with a microprocessor (µP) reset

input (Figure 2). The MAX6502/MAX6504 outputs are

intended for applications such as driving a fan control

(Figure 3).

Hysteresis Input

The HYST pin is a CMOS-compatible input that selects

hysteresis at either a high level (+10°C for HYST = VCC)

or a low level (+2°C for HYST = GND). Hysteresis pre-

vents the output from oscillating when the temperature

approaches the trip point. The HYST pin should not

float. Drive HYST close to ground or VCC. Other input

voltages cause increased supply current. The actual

amount of hysteresis depends on the part’s pro-

grammed trip threshold. (See the Typical Operating

Characteristics graphs.)

Table 1. Factory-Programmed Threshold

Range

+35°C < TTH < +115°C

THRESHOLD (TTH) RANGE

-45°C < TTH < +15°C

MAX6503

MAX6504

MAX6501

MAX6502

PART

MAX6501–MAX6504

Low-Cost, +2.7V to +5.5V, Micropower

Temperature Switches in SOT23 and TO-220

_______________________________________________________________________________________ 5

POSITIVE

TEMPCO

REFERENCE

NEGATIVE

TEMPCO

REFERENCE

HYST

NETWORK

TOVER

HYST

TOVER

TEMP

COLD +25°CT

MAX6501

POSITIVE

TEMPCO

REFERENCE

NEGATIVE

TEMPCO

REFERENCE

HYST

NETWORK

TOVER

HYST

TOVER

TEMP

COLD +25°CT

HOT

POSITIVE

TEMPCO

REFERENCE

NEGATIVE

TEMPCO

REFERENCE

HYST

NETWORK

TUNDER

HYST

TUNDER

TEMP

COLD TTH +25°C HOT

POSITIVE

TEMPCO

REFERENCE

NEGATIVE

TEMPCO

REFERENCE

HYST

NETWORK

TUNDER

HYST

TUNDER

TEMP

COLD TTH +25°C HOT

MAX6502

MAX6503

MAX6504

MAX6501

WITH 100kΩ PULL-UP

MAX6504

MAX6503

WITH 100kΩ PULL-UP

MAX6502

Figure 1. Block and Functional Diagrams

MAX6501–MAX6504

Low-Cost, +2.7V to +5.5V, Micropower

Temperature Switches in SOT23 and TO-220

6 _______________________________________________________________________________________

Applications Information

Thermal Considerations

The MAX6501–MAX6504 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 monitor-

ing is good thermal contact between the MAX6501–

MAX6504 package and the device being monitored. In

some applications, the SOT23-5 package may be small

enough to fit underneath a socketed µP, allowing the

device to monitor the µP’s temperature directly. The

TO-220 package can monitor the temperature of a heat

sink directly, and presents the lower thermal resistance

of the two packages. 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

MAX6501–MAX6504 die. Heat flows in and out of plastic

packages, primarily through the leads. Pin 2 of the

SOT23-5 package provides the lowest thermal resistance

to the die. Short, wide copper traces leading to the tem-

perature monitor ensure that heat transfers quickly and

reliably.

The rise in die temperature due to self-heating is given

by the following formula:

∆TJ= PDISSIPATION x θJA

where PDISSIPATION is the power dissipated by the

MAX6501–MAX6504, and θJA is the package’s thermal

resistance.

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

SOT23-5 package and 75°C/W for the TO-220 pack-

age. To limit the effects of self-heating, minimize the

output currents. For example, if the MAX6501 or

MAX6503 sink 1mA, the 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 temperature in the SOT23-5.

Temperature-Window Alarm

The MAX6501–MAX6504 temperature switch outputs

assert when the die temperature is outside the factory-

programmed range. Combining the outputs of two

devices creates an over/undertemperature alarm. The

MAX6501/MAX6503 and the MAX6502/MAX6504 are

designed to form two complementary pairs, each con-

taining one cold trip-point output and one hot trip-point

output. The assertion of either output alerts the system to

an out-of-range temperature. The MAX6502/MAX6504

push/pull output stages can be ORed to produce a ther-

mal out-of-range alarm. More favorably, a MAX6501/

MAX6503 can be directly wire-ORed with a single exter-

nal resistor to accomplish the same task (Figure 4).

The temperature window alarms shown in Figure 4 can

be used to accurately determine when a device’s tem-

perature falls out of the -5°C to +75°C range. The ther-

mal-overrange signal can be used to assert a thermal

shutdown, power-up, recalibration, or other temperature-

dependent function.

Low-Cost, Fail-Safe

Temperature Monitor

In high-performance/high-reliability applications, multiple

temperature monitoring is important. The high-level

integration and low cost of the MAX6501–MAX6504

facilitate the use of multiple temperature monitors to in-

crease system reliability. Figure 5’s application uses two

MAX6502s with different temperature thresholds to ensure

that fault conditions that can overheat the monitored

device cause no permanent damage. The first tempera-

ture monitor activates the fan when the die temperature

exceeds +45°C. The second MAX6502 triggers a system

shutdown if the die temperature reaches +75°C. The

second temperature monitor’s output asserts when a

wide variety of destructive fault conditions occur, includ-

ing latchups, short circuits, and cooling-system failures.

MAX6502

+5V

TOVERGNDGND

VCC HYST

µP FAN

HEAT

VCC

Figure 3. Overtemperature Fan Control

MAX6501

+3.3V

GNDHYST GND

VCC

µP

HEAT

VCC RPULL-UP

100k

TOVER

INT

SHUTDOWN

RESET

Figure 2. Microprocessor Alarm/Reset

MAX6501–MAX6504

Low-Cost, +2.7V to +5.5V, Micropower

Temperature Switches in SOT23 and TO-220

_______________________________________________________________________________________ 7

MAX6503_ _N005MAX6501_ _P075

+5V

HYSTHYST GND

GND

VCC

GNDGND

VCC

RPULL-UP

100k

TOVER TUNDER

OUT OF RANGE

MAX6502_ _P075

HYST

GND

+5V

MAX6504_ _N005

GND

HYST

VCC

TOVER

TUNDER

OUT OF RANGE

OVERTEMP

UNDERTEMP

Figure 4. Temperature-Window Alarms

MAX6502_ _P075

GND

GND HYST

+5V

MAX6502_ _P045

GND GND

HYST

VCC

TOVER

TEMPERATURE

FAULT

FAN

CONTROL

µP

HEAT

Figure 5. Low-Power, High-Reliability, Fail-Safe Temperature

Monitor

Table 2. Device Marking Codes for SOT23-5 Package

MAX6502UKP115 2.5kACFY

MAX6502UKP105 10kACFZ

MAX6504UKP015 10kADKE

MAX6504UKP005 2.5kABZY

MAX6504UKN005 10kACAT

MAX6504UKN015 2.5kACGD

MAX6504UKN025 10kACAV

MAX6504UKN035 10kACAW

MAX6504UKN045 10kACAX

DEVICE MINIMUM

ORDER

CODE

MAX6503UKP015 10kACAM

MAX6503UKP005 2.5kABZX

MAX6503UKN005 10kACAN

MAX6503UKN015 2.5kACFX

MAX6503UKN025 10kACAP

MAX6503UKN035 10kACAQ

MAX6503UKN045 10kADIZ

MAX6502UKP095 2.5kABZW

MAX6502UKP085 2.5kACGA

MAX6502UKP075 2.5kACGB

MAX6502UKP065 2.5kABZV

MAX6502UKP055 2.5kACGC

MAX6502UKP045 2.5kABZU

MAX6502UKP035 10kABZG

MAX6501UKP115 2.5kACAG

MAX6501UKP105 10kACFU

MAX6501UKP095 2.5kABZT

MAX6501UKP085 2.5kACDP

MAX6501UKP075 2.5kACFV

MAX6501UKP065 2.5kABZS

MAX6501UKP055 2.5kACFW

MAX6501UKP045 2.5kABZR

MAX6501UKP035 10kABZF

DEVICE MINIMUM

ORDER

CODE

MAX6501–MAX6504

Low-Cost, +2.7V to +5.5V, Micropower

Temperature Switches in SOT23 and TO-220

GND

VCC

HYST

( ) ARE FOR MAX6502.

15TOVER

(TOVER)

GND

MAX6501

MAX6502

SOT23-5

TOP VIEW

GND

VCC

HYST

( ) ARE FOR MAX6504.

15TUNDER

(TUNDER)

GND

MAX6503

MAX6504

SOT23-5

GND TOVER

(TOVER)

HYST GND

MAX6501

MAX6502

TO-220-7

GND VCC

HYST GND

MAX6503

MAX6504

TO-220-7

TUNDER

(TUNDER)

1234567 1234567

VCC

Pin Configurations

Chip Information

TRANSISTOR COUNT: 237

SUBSTRATE CONNECTED TO GND

PART MAX6501 MAX6502 MAX6503 MAX6504

OUTPUT

STAGE

Open-

Drain Push-Pull Open-

Drain Push-Pull

TRIP TEMP

THRESHOLD Hot Hot Cold Cold

✓ ✓

STANDARD TEMPERATURE THRESHOLDS (°C)

✓ ✓

Selector Guide

-45

-35

-25

-15

-5

+15

+35

+45

+55

+65

+75

+85

+95

+105

+115

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.

8_____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600