Rainbow Electronics MAX6677 User Manual
General Description
The MAX6676/MAX6677 are high-accuracy, low-power
temperature sensors with a single-wire output. The
MAX6676/MAX6677 convert the ambient temperature
into a ratiometric PWM output with temperature information contained in the duty cycle of the output square
wave. The MAX6676 has an open-drain output and the
MAX6677 has a push-pull output.
The MAX6676/MAX6677 are specified for operation
with power-supply voltages from 1.8V to 3.6V, or from
3.6V to 5.5V. The typical unloaded supply current is
80µA. All 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 1.8kHz (±20%) at +25°C. The
output format is decoded as follows:
Temperature (°C) = 398.15 ✕(t1/ t2) - 273.15
Where t1is fixed with a typical value of 0.24ms and t2is
modulated by the temperature. The MAX6676/
MAX6677 operate from -40°C to +125°C and are available in space-saving 6-pin SOT23 packages.
Applications
Process Control
Industrial
HVAC and Environmental Control
Automotive
Portable Devices
µP and µC Temperature Monitoring
Isolated Temperature Sensing
Features
♦ Simple Single-Wire, 1.8kHz PWM Output
♦ Operates Down to 1.8V
♦ High Accuracy
±1.5°C at TA= +25°C
±3.0°C at TA= 0°C to +85°C
♦ Operates from -40°C to +125°C
♦ Low 80µA Typical Current Consumption
♦ Small 6-Pin SOT23 Package
MAX6676/MAX6677
Low-Voltage, 1.8kHz PWM Output Temperature
Sensors
________________________________________________________________ Maxim Integrated Products 1
Pin Configuration
Ordering Information
V
CC
V
CC
*REQUIRED ONLY FOR MAX6676.
5.1kΩ*
GND
DOUT
µC
INPUT TO
TIMER/COUNTER
MAX6676
t
2
t
1
0.1µF
Typical Operating Circuit
19-2660; Rev 0; 10/02
*Future product—contact factory for availability.
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.
Selector Guide
PART
MAX6676AUT3-T -40°C to +125°C 6 SOT23-6
MAX6676AUT5-T* -40°C to +125°C 6 SOT23-6
MAX6677AUT3-T* -40°C to +125°C 6 SOT23-6
MAX6677AUT5-T* -40°C to +125°C 6 SOT23-6
TEMP
RANGE
PART
MAX6676AUT3 Open drain 1.8 to 3.6 ABBF
MAX6676AUT5 Open drain 3.6 to 5.5 ABBG
MAX6677AUT3 Push-pull 1.8 to 3.6 ABBH
MAX6677AUT5 Push-pull 3.6 to 5.5 ABBI
OUTPUT
TYPE
PINPACKAGE
SUPPLY
VOLTAGE
RANGE (V)
MARK
TOP
TOP VIEW
16GND
DOUT
GND
2
34
CC
MAX6676
MAX6677
SOT23
5 GND
GNDV
MAX6676/MAX6677
Low-Voltage, 1.8kHz PWM Output Temperature
Sensors
2 _______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS
(VCC= 1.8V to 3.6V (MAX6676AUT3/MAX6677AUT3), VCC= 3.6V to 5.5V (MAX6676AUT5/MAX6677AUT5), TA= -40°C to +125°C, unless
otherwise noted. Typical values are at V
CC
= 3.0V (MAX6676AUT3/MAX6677AUT3), VCC= 5.0V (MAX6676AUT5/MAX6677AUT5),
T
A
= +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.
Note 1: Parts are tested at +25°C. Specifications are guaranteed by design over temperature.
(Voltages Referenced to GND)
V
CC
........................................................................-0.3V to +6.0V
DOUT (MAX6676)..................................................-0.3V to +6.0V
DOUT (MAX6677).......................................-0.3V to (V
CC
+ 0.3V)
DOUT Current .....................................................-1mA to +50mA
ESD Protection (DOUT, Human Body Model) .................±2000V
Continuous Power Dissipation (T
A
= +70°C)
6-Pin SOT23 (derate 8.7mW/°C above +70°C).........695.7mW
Operating Temperature Range .........................-40°C to +125°C
Storage Temperature Range .............................-65°C to +150°C
Junction Temperature......................................................+150°C
Lead Temperature (soldering, 10s) .................................+300°C
Supply Voltage Range V
Supply Current I
Temperature Error
Nominal t1 Pulse Width 240 µs
Output High Voltage V
Output Leakage Current V
Output Low Voltage V
Fall Time t
Rise Time t
Digital Output Capacitance C
Power-Supply Rejection Ratio PSRR VCC = 1.8V - 3.6V -1.2 +0.4 +1.2 °C/V
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
MAX6676AUT3/MAX6677AUT3 1.8 3.6
CC
MAX6676AUT5/MAX6677AUT5 3.6 5.5
CC
OUT
RL = ∞ 80 200 µA
TA = +25°C
T
= 0°C to +85°C
A
T
= -20°C to +100°C -4.2 +4.2
A
= -40°C to +125°C
T
A
IOH = 800µA, MAX6677
OH
= VCC, MAX6676 0.1 µA
OUT
IOL = 3mA 0.5 V
OL
CL = 100pF, RL = 10kΩ 20 ns
F
MAX6676, CL = 15pF, RL = 10kΩ 300 ns
R
-1.5 +1.5
-3.0 +3.0
-5.5 +5.5
V
-
CC
0.5
15 pF
V
°C
V
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