Rainbow Electronics MAX6667 User Manual

General Description

The MAX6666/MAX6667 are high-accuracy, low-cost,
low-power temperature sensors with a single-wire
output. The MAX6666/MAX6667 convert the ambient
temperature into a ratiometric PWM output with temper­ature information contained in the duty cycle of the out­put square wave. The MAX6666 has a push-pull output
and the MAX6667 has an open-drain output.

The MAX6666/MAX6667 operate at supply voltages
from +3V to +5.5V. The typical unloaded supply current
at 5.0V is 200µA. Both devices feature a single-wire
output that minimizes the number of pins necessary to
interface with a microprocessor (µP). The output is a
square wave with a nominal frequency of 35Hz (±20%)
at +25°C. The output format is decoded as follows:

Temperature (°C) = 235 - (400 x t1) / t

2

Where t1is fixed with a typical value of 10ms and t2is
modulated by the temperature (Figure 1). The
MAX6666/MAX6667 operate from -40°C to +125°C and
are available in space-saving SOT23* and µMAX pack­ages.

Applications

Process Control

Industrial

HVAC and Environmental Control

Automotive

µP and µC Temperature Monitoring

Features

♦ Simple Single-Wire PWM Output

♦ ±1.0°C Accuracy at +25°C

♦ High Accuracy

±1°C at T

A

= +30°C

±2.5°C at TA= +10°C to +50°C

♦ Operate Up to +125°C

♦ Low 200µA Typical Current Consumption

♦ Multiple Package Options

6-Pin SOT23*
8-Pin SO
8-Pin µMAX

MAX6666/MAX6667

High-Accuracy PWM Output Temperature

Sensors

________________________________________________________________ Maxim Integrated Products 1

Pin Configurations

Ordering Information

V

CC

+3.3V

GND

DOUT

t

1

t

2

µC

INPUT TO
TIMER/COUNTER

MAX6666
MAX6667

Typical Operating Circuit

19-2138; Rev 0; 7/01

For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.

Pin Configurations continued at end of data sheet.

*Future product—contact factory for availability.

PART TEMP. RANGE PIN-PACKAGE

MAX6666AUT-T* -40°C to +125°C 6 SOT23-6

MAX6666AUA -40°C to +125°C 8 µMAX

MAX6666ASA -40°C to +125°C 8 SO

MAX6667AUT-T* -40°C to +125°C 6 SOT23-6

MAX6667AUA -40°C to +125°C 8 µMAX

MAX6667ASA -40°C to +125°C 8 SO

1

2

MAX6666
MAX6667

3

4

µMAX/SO

TOP VIEW

D

OUT

CC

GND

87IC

6

5

ICV

IC

ICIC

MAX6666/MAX6667

High-Accuracy PWM Output Temperature
Sensors

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

ELECTRICAL CHARACTERISTICS

(VCC= +3.0V to +5.5V, TA= -40°C to +125°C, unless otherwise noted. Typical values are at VCC= +3.3V, TA= +25°C.)

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.

(Voltages Referenced to GND)
V

CC

........................................................................-0.3V to +6.0V

D

OUT

MAX6666................................................-0.3V to (VCC+ 0.3V)

MAX6667 ..........................................................-0.3V to + 6.0V

D

OUT

Current ......................................................-1mA to +50mA

Continuous Current into Any Other Terminal....................±20mA

Continuous Power Dissipation (T

A

= +70°C)

6-Pin SOT23 (derate 8.7mW/°C above +70°C).........695.7mW

8-Pin µMAX (derate 4.1mW/°C above +70°C) .............330mW

8-Pin SO (derate 5.88mW/°C above +70°C)................471mW

Operating Temperature Range .........................-40°C to +150°C

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

Junction Temperature......................................................+150°C

Lead Temperature (soldering,10s).....................................+150°

Supply Voltage Range V

Supply Current I

Temperature Error VCC = +3.3V

Nominal t1 Pulse Width 10 ms

MAX6666 Output High Voltage IOH = 800µA V CC- 0.4 V

MAX6666 Output Low Voltage IOL = 800µA 0.4 V

MAX6666 Fall Time CL = 100pF, RL = ∞ 80 ns

MAX6666 Rise Time CL = 100pF, RL = ∞ 80 ns

MAX6667 Output Low Voltage

MAX6667 Fall Time CL = 100pF, RL = 10kΩ 40 ns

MAX6667 Output Capacitance CL = 0 15 pF

MAX6667 Output Leakage <0.1 µA

Power-Supply Rejection Ratio PSRR VCC = +3.0V to +5.5V 0.3 1.0 °C/V

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

CC

VCC = +3.0V to +5.5V 200 500 µA

CC

TA = +30°C -1 +1

TA= +10°C to +50°C -2.5 +2.5

TA= 0°C to +100°C -3.8 +3.8

TA= -25°C to +125°C -4.8 +4.8

TA= -40°C, VCC = +3.3V -6 +6

I

= 1.6mA 0.4

SINK

I

= 5.0mA 1.2

SINK

3.0 5.5 V

°C

V

MAX6666/MAX6667

High-Accuracy PWM Output Temperature

Sensors

_______________________________________________________________________________________ 3

Typical Operating Characteristics

(VCC= +3.3V, TA= +25°C, unless otherwise noted.)

OUTPUT FREQUENCY vs. TEMPERATURE

50

40

30

20

OUTPUT FREQUENCY (Hz)

10

0

-40 10-15 356085110
TEMPERATURE (°C)

MAX6666/7 toc01

45

40

35

30

OUTPUT FREQUENCY (Hz)

25

20

OUTPUT ACCURACY

vs. TEMPERATURE

MAX6666/7 toc04

210
200

190

180

170

160

150

140

SUPPLY CURRENT (µA)

130

120

110
100

3

2

1

0

-1

OUTPUT ACCURACY (°C)

-2

-3

-40 20 50-10 80 110

TEMPERATURE (°C)

OUTPUT FREQUENCY vs. SUPPLY VOLTAGE

TEMP = +125°C

TEMP = +25°C

TEMP = -40°C

3.0 4.03.5 4.5 5.0 5.5
SUPPLY VOLTAGE (V)

SUPPLY CURRENT

vs. TEMPERATURE

VCC = +5.5V

VCC = +3.3V

-55 5 35-25
TEMPERATURE (°C)

65

95 125 155

MAX6666/7 toc02

MAX6666/7 toc05

T1 AND T2 TIMES

vs. TEMPERATURE

39

TWO TYPICAL PARTS

34

29

T

24

TIME (ms)

19

14

9

-40 20 50-10 80 110 140

2

T

1

TEMPERATURE (°C)

SUPPLY CURRENT vs. SUPPLY VOLTAGE

158

156

154

152

150

148

146

SUPPLY CURRENT (µA)

144

142

140

3.0 4.03.5 4.5 5.0 5.5
SUPPLY VOLTAGE (V)

MAX6666/7 toc03

MAX6666/7 toc06

POWER-SUPPLY REJECTION RATIO

vs. TEMPERATURE

0.50

0.45

0.40

0.35

0.30

0.25

PSRR (°C/V)

0.20

0.15

0.10

0.05

0

-40 -15 10 35 60 85 110
TEMPERATURE (°C)

MAX6666/7 toc07

1.0

0.5

CHANGE IN TEMPERATURE (°C)

-0.5

-1.0

POWER-SUPPLY REJECTION

vs. FREQUENCY

MAX6666/7 toc08

0

VAC = 100mVp-p

0.01 10 100 1k0.1 1 10k

FREQUENCY (Hz)