MAX6654 1C Accurate Remote/Local Temperature Sensor with SMBus Serial Interface General Description Features The MAX6654 is a precise digital thermometer that High Accuracy 1C (max) from +70C to +100C reports the temperature of both a remote P-N junction (Remote) and its own die. The remote junction can be a diode-con- 11-Bit, 0.125C Resolution nected transistortypically a low-cost, easily mounted Dual Channel: Measures Remote and Local 2N3904 NPN type or 2N3906 PNP typethat replaces Temperature conventional thermistors or thermocouples. Remote No Calibration Required accuracy is 1C for multiple transistor manufacturers, with no calibration needed. The remote junction can also Programmable Under/Overtemperature Alarms be a common-collector PNP, such as a substrate PNP of 2 I C-Compatible/SMBus Interface a microprocessor (P). +3V to +5.5V Supply Range The 2-wire serial interface accepts standard System Management Bus (SMBus), Write Byte, Read Byte, Send Ordering Information Byte, and Receive Byte commands to program the alarm thresholds and to read temperature data. Measurements PART TEMP RANGE PIN-PACKAGE can be done automatically and autonomously, with the conversion rate programmed by the user, or programmed MAX6654MEE+ -55C to +125C 16 QSOP to operate in a single-shot mode. The adjustable conver- +Denotes a lead(Pb)-free/RoHS-compliant part. sion rate allows the user to optimize supply current and temperature update rate to match system needs. When the conversion rate is faster than 1Hz, the conversion Typical Operating Circuit results are available as a 7-bit-plus-sign byte with a 1C LSB. When the conversion rate is 1Hz or slower, the 0.1F +3.3V SUPPLY MAX6654 enters the extended mode. In this mode, 3 additional bits of temperature data are available in the extended resolution register, providing 10-bit-plus-sign 10k EACH V STBY CPU CC resolution with a 0.125C LSB. Single-shot conversions MAX6654 also have 0.125C per LSB resolution when the conver- DXP SMBCLK CLOCK sion rate is 1Hz or slower. SMBDATA A parasitic resistance cancellation (PRC) mode can also DATA be invoked for conversion rates of 1Hz or slower by set- DXN ALERT 2200pF ting bit 4 of the configuration register to 1. In PRC mode, INTERRUPT TO C the effect of series resistance on the leads of the external ADD0 ADD1 GND diode is canceled. The 11-bit conversion in PRC mode is performed in <500ms and is disabled for conversion rates faster than 1Hz. The one-shot conversion is also 11 bits in <500ms. The MAX6654 default low-temperature measurement limit is 0C. This can be extended to -64C by setting bit Pin Configuration 5 of the configuration register to 1. TOP VIEW The MAX6654 is available in a small, 16-pin QSOP sur- face-mount package. N.C. 1 16 N.C. V 2 15 STBY CC DXP 3 14 SMBCLK Applications DXN 4 MAX6654 13 N.C. Desktop Computers Workstations Notebook Computers Test and Measurement N.C. 5 12 SMBDATA Servers Multichip Modules ADD1 6 11 ALERT Thin Clients GND 7 10 ADD0 GND 9 N.C. 8 QSOP For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim Integrateds website at www.maximintegrated.com. 19-1836 Rev 4 6/13MAX6654 1C Accurate Remote/Local Temperature Sensor with SMBus Serial Interface ABSOLUTE MAXIMUM RATINGS (All voltages are referenced to GND unless otherwise noted.) Continuous Power Dissipation (T = +70C) A V ..........................................................................-0.3V to +6V 16-Pin QSOP (derate 8.30mW/C above +70C).........667mW CC DXP, ADD ................................................-0.3V to (VCC + 0.3V) Operating Temperature Range ........................-55C to +125C DXN ......................................................................-0.3V to +0.8V Junction Temperature......................................................+150C SMBCLK, SMBDATA, ALERT, STBY......................-0.3V to +6V Storage Temperature Range ............................-65C to +165C SMBDATA, ALERT Current .................................-1mA to +50mA Lead Temperature (soldering, 10s) .................................+300C DXN Current ......................................................................1mA Soldering Temperature (reflow) .......................................+260C ESD Protection (all pins, Human Body Model)................2000V 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 (V = +3V to +5.5V, T = -55C to +125C, unless otherwise noted. Typical values are at V = +3.3V and T = +25C.) CC A CC A PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS TEMPERATURE-TO-DIGITAL CONVERTER +60C T +100C, V = +3.3V -1.3 +1.3 A CC Accuracy (Local Sensor) 0C T +100C, V = +3.3V -2 +2 C A CC -55C T +120C, V = +3.3V -5 +5 A CC + 70 C T + 100 C , V = + 3.3V ( N ote 1) -1 +1 R J C C Accuracy (Remote Sensor) 0C T +100C, V = +3.3V (Note 1) -2 +2 C RJ CC - 55C T + 120C , V = + 3.3V ( Notes 1, 2) -5 +5 RJ C C Line Regulation 0.2 0.5 C +1 C Resolution (Legacy Mode) Conversion rate >1Hz +8 Bits +0.125 C Resolution (Extended Mode) Conversion rate 1Hz +11 Bits Undervoltage Lockout V input, disables A/D conversion, CC UVLO +2.60 +2.80 +2.95 V Threshold rising edge Undervoltage Lockout +90 mV Hysteresis Supply Voltage Range V +3.0 +5.5 V CC P ower - O n Reset (P O R) Thres hold V , falling edge +1.5 +2.0 +2.5 V CC POR Threshold Hysteresis +90 mV Standby Current SMBus static +3 +10 A Operating Current During conversion +0.55 +1 mA 0.25 conversion/s (Note 3) +40 +70 Average Operating Current A 2 conversion/s (Note 3) +150 +250 From stop bit to conversion completed, in Conversion Time t +95 +125 +156 ms CONV legacy mode (Note 3) Conversion Timing Error 25 % High level +80 +100 +120 Remote Diode Current I A RJ Low level +8 +10 +12 2 Maxim Integrated