MAX6576LZUT+T

MAX6576/MAX6577 SOT Temperature Sensors with Period/Frequency Output 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 VDD or 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 Pin Configuration ●● 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 Ordering Information PART TEMP. RANGE PINPACKAGE MAX6576ZUT -40°C to +125°C 6 SOT23 AABI MAX6577ZUT -40°C to +125°C 6 SOT23 AABJ +2.7V TO +5.5V VDD 1 MAX6576 MAX6577 6 OUT 5 TS1 0.1µF N.C. 3 4 SOT23-6 TS0 0.1µF VDD MAX6576 MAX6577 VCC µP TS1 TS0 19-1484; Rev 1; 10/14 SOT TOP MARK Typical Operating Circuit TOP VIEW GND 2 Features GND OUT GND I/O MAX6576/MAX6577 SOT Temperature Sensors with Period/Frequency Output Absolute Maximum Ratings Terminal Voltage (with respect to GND) VDD.......................................................................-0.3V to +6V TS1, TS0, OUT.......................................-0.3V to (VDD + 0.3V) Input/Output Current, All Pins............................................±20mA Continuous Power Dissipation (TA = +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 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. 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.) PARAMETER VDD Range Supply Current SYMBOL CONDITIONS VDD IDD VDD = 5.5V Temperature Sensor Error (Note 1) MAX6577 Output Clock Frequency tOUT fOUT MAX6576, T (temp) in °K, Figure 1 MAX6577, T (temp) in °K, Figure 2 TA = -40°C to +85°C MAX UNITS 5.5 V 140 250 TA = -40°C to +125°C 400 TA = -20°C -7.5 ±1.1 +7.5 TA = 0°C -5.5 ±0.9 +5.5 TA = +25°C -3.0 ±0.8 +3.0 TA = +85°C -4.5 ±0.5 +4.5 TA = +125°C -5.0 ±0.5 +5.0 TA = -20°C -7.5 ±1.1 +7.5 TA = 0°C -6.5 ±0.9 +6.5 TA = +25°C -3.0 ±0.8 +3.0 TA = +85°C -3.5 ±0.5 +3.5 TA = +125°C -4.5 ±0.5 +4.5 VTS1 = GND, VTS0 = GND µA °C °C 10T VTS1 = GND, VTS0 = VDD 40T VTS1 = VDD, VTS0 = GND 160T VTS1 = VDD, VTS0 = VDD 640T VTS1 = GND, VTS0 = GND 4T VTS1 = GND, VTS0 = VDD 1T VTS1 = VDD, VTS0 = GND T/4 VTS1 = VDD, VTS0 = VDD T/16 OUT Duty Cycle (Note 2) Time-Select Pin Logic Levels TYP 2.7 MAX6576 Output Clock Period MIN µs Hz 0.5 VIL 0.8 VIH VOL OUT Voltage VOH 2.3 VDD > 4.5V, ISINK = 3.2mA 0.4 VDD > 2.7V, ISINK = 1.2mA 0.3 VDD > 4.5V, ISRC = 800μA VDD - 1.5 VDD > 2.7V, ISRC = 500μA 0.8VDD V V 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. www.maximintegrated.com Maxim Integrated │  2 MAX6576/MAX6577 SOT Temperature Sensors with Period/Frequency Output Typical Operating Characteristics MAX6576 MAX6577 30 25 20 15 10 5 0 -5 -4 -3 -2 -1 0 1 2 3 4 60 40 30 20 10 SUPPLY CURRENT vs. TEMPERATURE MAX6576/77toc03 160 MAX6576 140 130 120 MAX6577 110 100 1.5 0 1 2 3 4 5 ACCURACY vs. TEMPERATURE 1.0 ACCURACY (°C) SUPPLY CURRENT (µA) 170 150 -5 -4 -3 -2 -1 ACCURACY (°C) ACCURACY (°C) 180 MAX6576 MAX6577 50 0 5 SAMPLE SIZE = 200 MAX6576 toc02 SAMPLE SIZE = 200 TEMPERATURE ACCURACY (TA = +85°C) MAX6575 toc04 35 PERCENTAGE OF PARTS SAMPLED (%) TEMPERATURE ACCURACY (TA= +25°C) MAX6576 toc01 PERCENTAGE OF PARTS SAMPLED (%) (VDD = +5V, TA = +25°C, unless otherwise noted.) 0.5 MAX6577 0 -0.5 -40 -25 -10 5 20 35 50 65 80 95 110 125 -1.0 MAX6576 -40 -25 -10 5 20 35 50 65 80 95 110 125 TEMPERATURE (°C) TEMPERATURE (°C) THERMAL STEP RESPONSE IN PERFLUORINATED FLUID THERMAL STEP RESPONSE IN STILL AIR MAX6576/77 toc05 MAX6576/77 toc06 +100°C +100°C +15°C/div +12.5°C/div MOUNTED ON 0.75 in.2 OF 2oz. COPPER MOUNTED ON 0.75 in.2 OF 2oz. COPPER +25°C 5sec/div www.maximintegrated.com +25°C 20sec/div Maxim Integrated │  3 MAX6576/MAX6577 SOT Temperature Sensors with Period/Frequency Output Pin Description PIN NAME 1 VDD Positive Supply Voltage FUNCTION 2 GND Ground 3 N.C. No Connection. Connect pin to GND or leave open. 4, 5 TS1, TS0 6 OUT Time-Select Pins. TS1 and TS0 set the temperature scale factor by connecting TS1 and TS0 to either VDD or GND. See Tables 1 and 2. Square-Wave Output with a Clock Period Proportional to Absolute Temperature (°K) (MAX6576) Square-Wave Output with a Clock Frequency Proportional to Absolute Temperature (°K) (MAX6577) Table 1. MAX6576 Time-Select Pin Configuration Table 2. MAX6577 Time-Select Pin Configuration TS1 TS0 SCALAR MULTIPLIER (μs/°K) TS1 TS0 SCALAR MULTIPLIER (Hz/°K) GND GND 10 GND GND 4 GND VDD 40 GND VDD 1 VDD GND 160 VDD GND 1/4 VDD VDD 640 VDD VDD 1/16 Note: The temperature, in °C, may be calculated as follows: T(°C) Note: The temperature, in °C, may be calculated as follows: PERIOD(µs) FREQUENCY(µs) − 273.15 = °K T(°C) − 273.15°K SCALAR MULTIPLIER(µs/ °K) SCALAR MULTIPLIER(µs/ °K) Detailed Description The MAX6576/MAX6577 low-cost, low-current (140μA typ) temperature sensors are ideal for interfacing with microcontrollers (μCs) or microprocessors (μPs). The MAX6576 converts ambient temperature into a 50% dutycycle square wave with a period proportional to absolute temperature. The MAX6577 converts ambient temperature into a 50% duty-cycle square wave with a frequency proportional to absolute temperature. Timeselect pins (TS1, TS0) permit the internal temperaturecontrolled oscillator (TCO) to be scaled by four preset multipliers. The MAX6576/MAX6577 feature a single-wire interface to minimize the number of port pins necessary for interfacing with a μP. MAX6576 Characteristics The MAX6576 temperature sensor converts temperature to period. The output of the device is a free-running, 50% duty-cycle square wave with a period that is proportional www.maximintegrated.com to the absolute temperature (°K) of the device (Figure 1). The MAX6576 has a push/pull CMOS output with sharp edges. The speed of the output square wave can be selected by hard-wiring TS1 and TS0 as shown in Table 1. One of four scaled output periods can be selected using TS1 and TS0. MAX6577 Characteristics The MAX6577 temperature sensor converts temperature to frequency. The output of the device is a free-running, 50% duty-cycle square wave with a frequency that is proportional to the absolute temperature (°K) of the device (Figure 2). The MAX6577 has a push/pull CMOS output with sharp edges. The speed of the output square wave can be selected by hard-wiring TS1 and TS0 as shown in Table 2. One of four scaled output frequencies can be selected using TS1 and TS0. Maxim Integrated │  4 MAX6576/MAX6577 MAX6576 CLOCK WAVEFORM OUTPUT tOUT SOT Temperature Sensors with Period/Frequency Output MAX6577 CLOCK WAVEFORM OUTPUT tOUT fOUT = 1 / tOUT fOUT (°K) Figure 1. MAX6576 Timing Diagram Figure 2. MAX6577 Timing Diagram Applications Information VDD to select a scalar multiplier of 1Hz/°K. The MAX6577 converts the ambient temperature into a square wave with a frequency that is equal to the absolute temperature of the device in Hertz. The 8051 μC reads the frequency of the square-wave output of the MAX6577 into Timer 0 and displays the temperature as degrees Celsius in binary on Port 1. Listing 1 provides the code for this application. The interface is similar for the MAX6576, except the μC will perform a period measurement. Quick-Look Circuits Figure 3 shows a quick-look application circuit for the MAX6576 using a universal counter measuring period. TS1 and TS0 are both tied to ground to select a scalar multiplier of 10μs/°K. The MAX6576 converts the ambient temperature into a square wave with a period that is 10 times the absolute temperature of the device in μs. At room temperature, the universal counter will display approximately 2980μs. Figure 4 shows a quick-look application circuit for the MAX6577 using a universal counter measuring frequency. TS1 is tied to ground and TS0 is tied to VDD to select a scalar multiplier of 1Hz/°K. The MAX6577 converts the ambient temperature into a square wave with a frequency that is equal to the absolute temperature of the device in Hertz. At room temperature, the universal counter will display approximately 298Hz. Interfacing with a Microcontroller Noise Considerations The accuracy of the MAX6576/MAX6577 is susceptible to noise generated both internally and externally. The effects of external noise can be minimized by placing a 0.1μF ceramic bypass capacitor close to the supply pin of the devices. Internal noise is inherent in the operation of the devices and is detailed in Table 3. Internal averaging minimizes the effect of this noise when using longer scalar timeout multipliers. The effects of this noise are included in the overall accuracy of the devices as specified in the Electrical Characteristics. Figure 5 shows the MAX6577 interfaced with an 8051 μC. In this example, TS1 is tied to ground and TS0 is tied to www.maximintegrated.com Maxim Integrated │  5 MAX6576/MAX6577 SOT Temperature Sensors with Period/Frequency Output +2.7V TO +5.5V 0.1µF 470Ω x 8 VDD MAX6576 TS0 VCC P1.0 UNIVERSAL COUNTER P1.1 +2.7V TO +5.5V P1.2 "PERIOD" OUT TS1 P1.3 GND P1.4 0.1µF VDD P1.5 MAX6577 TS0 OUT P1.6 T0 P1.7 TS1 Figure 3. MAX6576 Quick-Look Circuit 22pF GND X1 8051 GND +2.7V TO +5.5V VDD MAX6577 TS0 0.1µF UNIVERSAL COUNTER 12MHz X2 22pF Figure 5. Interfacing with a μC "FREQUENCY" OUT TS1 GND Chip Information TRANSISTOR COUNT: 302 Figure 4. MAX6577 Quick-Look Circuit Table 3. Typical Peak Noise Amplitude PARAMETER MAX6576 MAX6577 Scalar Multiplier 10 40 160 640 4 1 1/4 1/16 Noise Amplitude (°C) ±0.38 ±0.17 ±0.11 ±0.094 ±0.13 ±0.066 ±0.040 ±0.028 www.maximintegrated.com Maxim Integrated │  6 MAX6576/MAX6577 SOT Temperature Sensors with Period/Frequency Output Listing 1. 8051 Code Example www.maximintegrated.com Maxim Integrated │  7 MAX6576/MAX6577 SOT Temperature Sensors with Period/Frequency Output Listing 1. 8051 Code Example (continued) Package Information For the latest package outline information and land patterns (footprints), go to www.maximintegrated.com/packages. Note that a “+”, “#”, or “-” in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing pertains to the package regardless of RoHS status. PACKAGE TYPE PACKAGE CODE OUTLINE NO. LAND PATTERN NO. 6 SOT23 U6-4 21-0058 90-0175 www.maximintegrated.com Maxim Integrated │  8 MAX6576/MAX6577 SOT Temperature Sensors with Period/Frequency Output Revision History REVISION NUMBER REVISION DATE 0 4/99 Initial release — 1 10/14 Removed automotive reference from data sheet 1 DESCRIPTION PAGES CHANGED For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim Integrated’s website at www.maximintegrated.com. Maxim Integrated cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim Integrated product. No circuit patent licenses are implied. Maxim Integrated reserves the right to change the circuitry and specifications without notice at any time. The parametric values (min and max limits) shown in the Electrical Characteristics table are guaranteed. Other parametric values quoted in this data sheet are provided for guidance. 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