Rainbow Electronics MAX6577 User Manual

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General Description

The MAX6576/MAX6577 are low-cost, low-current tem­perature sensors with a single-wire output. The MAX6576
converts the ambient temperature into a square wave
with a period proportional to absolute temperature (°K).
The MAX6577 converts the ambient temperature into a
square wave with a frequency proportional to absolute
temperature. The MAX6576 offers accuracy of ±3°C at
+25°C, ±4.5°C at +85°C, and ±5°C at +125°C. The
MAX6577 offers accuracy of ±3°C at +25°C, ±3.5°C at
+85°C, and ±4.5°C at +125°C.

Both devices feature a single-wire output that minimizes
the number of pins necessary to interface with a micro­processor. The period/frequency range of the output
square wave can be selected by hard-wiring the two
time-select pins (TS0, TS1) to either VDDor GND. The
MAX6576/MAX6577 are available in space-saving 6-pin
SOT23 packages.

Applications

Critical µP and µC Temperature Monitoring
Portable Battery-Powered Equipment
Cell Phones
Battery Packs
Hard Drives/Tape Drives
Networking and Telecom Equipment
Medical Equipment
Automotive

Features

♦ Simple Single-Wire Output
♦ Two Output Types Available

Temperature to Period (µs) (MAX6576)
Temperature to Frequency (Hz) (MAX6577)

♦ ±0.8°C Accuracy at +25°C (±3°C max)
♦ No External Components
♦ Operates from +2.7V to +5.5V Supply Voltage
♦ Low 140µA Typical Supply Current
♦ Standard Operating Temperature Range:

-40°C to +125°C

♦ Small 6-Pin SOT23 Package

MAX6576/MAX6577

SOT Temperature Sensors with

Period/Frequency Output

________________________________________________________________

Maxim Integrated Products

1

+2.7V TO +5.5V

GND

TS0

TS1

OUT

0.1µF

0.1µF

V

DD

MAX6576
MAX6577

µP

GND

I/O

V

CC

19-1484; Rev 0; 4/99

PART

MAX6576ZUT
MAX6577ZUT

-40°C to +125°C

-40°C to +125°C

TEMP. RANGE

PIN-

PACKAGE

6 SOT23
6 SOT23

Typical Operating Circuit

Ordering Information

SOT

TOP MARK

AABI

AABJ

GND

TS0N.C.

16OUT

5 TS1

V

DD

MAX6576
MAX6577

SOT23-6

TOP VIEW

2

34

Pin Configuration

MAX6576/MAX6577

SOT Temperature Sensors with
Period/Frequency Output

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

ELECTRICAL CHARACTERISTICS

(VDD= +2.7V to +5.5V, TA= -40°C to +125°C, unless otherwise noted. Typical values are specified at TA= +25°C and VDD= +5V,
unless otherwise noted.)

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: See the Temperature Accuracy histograms in the

Typical Operating Characteristics

.

Note 2: The output duty cycle is guaranteed to be 50% by an internal flip-flop.

Terminal Voltage (with respect to GND)

V

DD

......................................................................-0.3V to +6V

TS1, TS0, OUT.......................................-0.3V to (V

DD

+ 0.3V)

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

Continuous Power Dissipation (T

A

= +70°C)

6-pin SOT23 (derate 7.10mW/°C above +70°C).........571mW

Operating Temperature Range .........................-40°C to +125°C

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

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

MAX6576

VDD= 5.5V

VDD> 2.7V, I

SINK

= 1.2mA

VDD> 4.5V, I

SINK

= 3.2mA

MAX6576,
T (temp) in °K,
Figure 1

MAX6577

CONDITIONS

0.3
V

0.4

V

OL

OUT Voltage

2.3V

IH

V

0.8V

IL

Time-Select Pin Logic
Levels

0.5OUT Duty Cycle (Note 2)

640T

°C

-7.5 ±1.1 +7.5

Temperature Sensor
Error (Note 1)

µA

140 250

I

DD

V2.7 5.5V

DD

VDDRange
Supply Current

160T

40T

µs

10T

t

OUT

Output Clock Period

-3.0 ±0.8 +3.0

-5.5 ±0.9 +5.5

-3.0 ±0.8 +3.0

-7.5 ±1.1 +7.5

-6.5 ±0.9 +6.5

UNITSMIN TYP MAXSYMBOLPARAMETER

TA= -20°C
TA= 0°C
TA= +25°C

TA= -20°C
TA= 0°C
TA= +25°C

V

TS1

= VDD, V

TS0

= V

DD

MAX6577,
T (temp) in °K,
Figure 2

V

TS1

= VDD, V

TS0

= V

DD

T/16

T/4

1T

Hz

4T

f

OUT

Output Clock Frequency

VDD> 4.5V, I

SRC

= 800µA VDD- 1.5

V

OH

VDD> 2.7V, I

SRC

= 500µA 0.8V

DD

V

TS1

= GND, V

TS0

= GND

V

TS1

= GND, V

TS0

= V

DD

V

TS1

= VDD, V

TS0

= GND

V

TS1

= GND, V

TS0

= GND

V

TS1

= GND, V

TS0

= V

DD

V

TS1

= VDD, V

TS0

= GND

TA= -40°C to +85°C
TA= -40°C to +125°C 400

°C

-3.5 ±0.5 +3.5TA= +85°C

-4.5 ±0.5 +4.5TA= +125°C

TA= +85°C -4.5 ±0.5 +4.5
TA= +125°C -5.0 ±0.5 +5.0

MAX6576/MAX6577

SOT Temperature Sensors with

Period/Frequency Output

_______________________________________________________________________________________

3

0

10

5

15

20

25

30

35

-5 -3 -2-4 -1012345

TEMPERATURE ACCURACY

(T

A

= +25°C)

MAX6576 toc01

ACCURACY (°C)

PERCENTAGE OF PARTS SAMPLED (%)

MAX6576
MAX6577

SAMPLE SIZE = 200

0

20

10

30

40

50

60

-5 -3 -2-4 -1012345

TEMPERATURE ACCURACY

(T

A

= +85°C)

MAX6576 toc01

ACCURACY (°C)

PERCENTAGE OF PARTS SAMPLED (%)

MAX6576
MAX6577

SAMPLE SIZE = 200

100

130
120
110

150
140

170
160

180

-40 -10 5 20-25 35 50 65 80 95 110 125

SUPPLY CURRENT vs. TEMPERATURE

MAX6576/77toc02

TEMPERATURE (°C)

SUPPLY CURRENT (µA)

MAX6577

MAX6576

-1.0

0

-0.5

1.0

0.5

1.5

-40 -10 5 20-25 35 50 65 80 95 110 125

ACCURACY vs. TEMPERATURE

MAX6575 toc04

TEMPERATURE (°C)

ACCURACY (°C)

MAX6576

MAX6577

+15°C/div

+100°C

+25°C

THERMAL STEP RESPONSE
IN PERFLUORINATED FLUID

MAX6576/77 toc05

5sec/div

MOUNTED ON 0.75 in.

2

OF 2oz. COPPER

+12.5°C/div

+100°C

+25°C

THERMAL STEP RESPONSE

IN STILL AIR

MAX6576/77 toc06

20sec/div

MOUNTED ON 0.75 in.

2

OF 2oz. COPPER

Typical Operating Characteristics

(VDD= +5V, TA = +25°C, unless otherwise noted.)