MAX6648MUA+

19-2545; Rev 4; 6/08 Precision SMBus-Compatible Remote/Local Temperature Sensors with Overtemperature Alarms The MAX6648/MAX6692 are precise, two-channel digital temperature sensors. They accurately measure the temperature of their own die and a remote PN junction, and report the temperature in digital form using a 2-wire serial interface. The remote PN junction is typically the emitter-base junction of a common-collector PNP on a CPU, FPGA, or ASIC. The 2-wire serial interface accepts standard System Management Bus (SMBus)™ write byte, read byte, send byte, and receive byte commands to read the temperature data and to program the alarm thresholds. To enhance system reliability, the MAX6648/MAX6692 include an SMBus timeout. A fault queue prevents the ALERT and OVERT outputs from setting until a fault has been detected one, two, or three consecutive times (programmable). The MAX6648/MAX6692 provide two system alarms: ALERT and OVERT. ALERT asserts when any of four temperature conditions are violated: local overtemperature, remote overtemperature, local undertemperature, or remote undertemperature. OVERT asserts when the temperature rises above the value in either of the two OVERT limit registers. The OVERT output can be used to activate a cooling fan, or to trigger a system shutdown. Measurements can be done autonomously, with the conversion rate programmed by the user, or in a singleshot mode. The adjustable conversion rate allows the user to optimize supply current and temperature update rate to match system needs. Remote accuracy is ±0.8°C maximum error between +25°C and +125°C with no calibration needed. The MAX6648/MAX6692 operate from -55°C to +125°C, and measure temperatures between 0°C and +125°C. The MAX6648 is available in an 8-pin µMAX® package, and the MAX6692 is available in 8-pin µMAX and SO packages. Features o Dual Channel Measures Remote and Local Temperature o +0.125°C Resolution o High Accuracy ±0.8°C (max) from +25°C to +125°C (Remote), and ±2°C (max) from +60°C to +100°C (Local) o Two Alarm Outputs: ALERT and OVERT o Two Default OVERT Thresholds Available MAX6648: +110°C MAX6692: +85°C o Programmable Conversion Rate o SMBus-Compatible Interface o SMBus Timeout o Programmable Under/Overtemperature Alarm Thresholds o Compatible with 90nm, 65nm, and 45nm Process Technology Ordering Information PINPACKAGE PART 8 µMAX MAX6648MUA 0°C to +125°C MAX6648YMUA 8 µMAX 0°C to +125°C MAX6692MUA 8 µMAX 0°C to +125°C MAX6692MSA 8 SO 0°C to +125°C MAX6692YMUA 8 µMAX 0°C to +125°C MAX6692YMSA 8 SO 0°C to +125°C Note: All devices operate over the -55°C to +125°C temperature range. Typical Operating Circuit Applications 3.3V 0.1μF Desktop Computers Notebook Computers 200Ω VCC 10kΩ EACH Servers DXP Thin Clients Test and Measurement SMBus is a trademark of Intel Corp. µMAX is a registered trademark of Maxim Integrated Products, Inc. SDA MAX6648 SCLK MAX6692 Workstations Multichip Modules MEASURED TEMP RANGE 2200pF μP DXN GND DATA CLOCK ALERT INTERRUPTED TO μP OVERT TO FAN DRIVER OR SYSTEM SHUTDOWN Pin Configuration and Functional Diagram appear at end of data sheet. ________________________________________________________________ Maxim Integrated Products For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim's website at www.maxim-ic.com. 1 MAX6648/MAX6692 General Description MAX6648/MAX6692 Precision SMBus-Compatible Remote/Local Temperature Sensors with Overtemperature Alarms ABSOLUTE MAXIMUM RATINGS (All voltages referenced to GND.) VCC ...........................................................................-0.3V to +6V DXP.............................................................-0.3V to (VCC + 0.3V) DXN .......................................................................-0.3V to +0.8V SCLK, SDA, ALERT, OVERT.....................................-0.3V to +6V SDA, ALERT, OVERT Current .............................-1mA to +50mA DXN Current .......................................................................±1mA Continuous Power Dissipation (TA = +70°C) 8-Pin µMAX (derate 5.9mW/°C above +70°C) .............471mW 8-Pin SO (derate 5.9mW/°C above +70°C)..................471mW ESD Protection (all pins, Human Body Model) ................±2000V Junction Temperature ......................................................+150°C Operating Temperature Range .........................-55°C to +125°C Storage Temperature Range .............................-65°C to +150°C Lead Temperature (soldering, 10s) .................................+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 (VCC = 3.0V to 5.5V, TA = -55°C to +125°C, unless otherwise specified. Typical values are at VCC = 3.3V and TA = +85°C.) (Note 1) PARAMETER Supply Voltage SYMBOL CONDITIONS VCC MIN 3.0 MAX 5.5 0.125 Temperature Resolution -0.8 +0.8 TRJ = +60°C to +100°C -1.0 +1.0 TRJ = 0°C to +125°C -1.6 +1.6 VCC = 3.3V, +0°C TRJ = 0°C to +125°C ≤ TA ≤ +100°C -3.0 +3.0 TA = +60°C to +100°C -2.0 +2.0 TA = 0°C to +125°C -3.0 +3.0 Local Temperature Error VCC = 3.3V Local Temperature Error (MAX6648Y/MAX6692Y) VCC = 3.3V °C TA = +60°C to +100°C -4.0 TA = 0°C to +125°C -4.4 Supply Sensitivity of Temperature Error Falling edge of VCC disables ADC 2.4 UVLO Hysteresis 2.7 °C °C ±0.2 UVLO V Bits TRJ = +25°C to +125°C VCC = 3.3V, +60°C ≤ TA ≤ +100°C Remote Temperature Error n = 1.008 UNITS °C 10 VCC = 3.3V, TA = +85°C Undervoltage Lockout (UVLO) Threshold TYP °C/V 2.95 V 90 mV VCC falling edge 2.0 V Standby Supply Current SMBus static 3.5 12 µA Operating Current During conversion 0.45 0.8 mA Power-On-Reset (POR) Threshold POR Threshold Hysteresis 90 Average Operating Current Conversion Time tCONV 0.25 conversions per second 40 80 2 conversions per second 250 400 125 156 From stop bit to conversion completion Conversion Time Error DXP and DXN Leakage Current 2 mV 95 -25 Standby mode _______________________________________________________________________________________ µA ms +25 % 100 nA Precision SMBus-Compatible Remote/Local Temperature Sensors with Overtemperature Alarms (VCC = 3.0V to 5.5V, TA = -55°C to +125°C, unless otherwise specified. Typical values are at VCC = 3.3V and TA = +85°C.) (Note 1) PARAMETER SYMBOL Remote-Diode Source Current IRJ MIN TYP MAX High level CONDITIONS 80 100 120 Low level 8 10 12 UNITS µA ALERT, OVERT Output Low Voltage Output High Leakage Current ISINK = 1mA 0.4 ISINK = 4mA 0.6 VOH = 5.5V 1 µA 0.8 V V SMBus-COMPATIBLE INTERFACE (SCLK AND SDA) Logic Input Low Voltage VIL Logic Input High Voltage VIH VCC = 3.0V 2.2 VCC = 5.5V 2.6 Input Leakage Current ILEAK VIN = GND or VCC -1 Output Low-Sink Current ISINK VOL = 0.6V 6 Input Capacitance CIN V +1 µA mA 5 pF SMBus-COMPATIBLE TIMING (Note 2) Serial Clock Frequency fSCLK Bus Free Time Between STOP and START Condition tBUF (Note 3) START Condition Setup Time 100 kHz 4.7 µs 4.7 µs Repeat START Condition Setup Time tSU:STA 90% to 90% 50 ns START Condition Hold Time tHD:STA 10% of SDA to 90% of SCLK 4 µs STOP Condition Setup Time tSU:STO 90% of SCLK to 90% of SDA 4 µs Clock Low Period tLOW 10% to 10% 4.7 µs Clock High Period tHIGH 90% to 90% 4 µs Data Setup Time tHD:DAT (Note 4) 250 µs Receive SCLK/SDA Rise Time tR 1 µs Receive SCLK/SDA Fall Time tF 300 ns Pulse Width of Spike Suppressed SMBus Timeout Note 1: Note 2: Note 3: Note 4: tSP tTIMEOUT SDA low period for interface reset 0 25 37 50 ns 55 ms All parameters tested at a single temperature. Specifications over temperature are guaranteed by design. Timing specifications guaranteed by design. The serial interface resets when SCLK is low for more than tTIMEOUT. A transition must internally provide at least a hold time to bridge the undefined region (300ns max) of SCLK’s falling edge. _______________________________________________________________________________________ 3 MAX6648/MAX6692 ELECTRICAL CHARACTERISTICS (continued) Typical Operating Characteristics (VCC = 3.3V, TA = +25°C, unless otherwise noted.) 2.8 2.4 400 300 200 3.5 4.0 4.5 5.0 0.5 -0.5 TA = +85°C FAIRCHILD 2N3906 -2.5 5.5 0.63 0.13 0.25 0.50 1.00 2.00 0 4.00 25 50 75 100 125 SUPPLY VOLTAGE (V) CONVERSION RATE (Hz) TEMPERATURE (°C) REMOTE TEMPERATURE ERROR vs. 45nm REMOTE DIODE TEMPERATURE LOCAL TEMPERATURE ERROR vs. DIE TEMPERATURE TEMPERATURE ERROR vs. POWER-SUPPLY NOISE FREQUENCY 0 -2 0.6 0.4 0.2 0 -0.2 -0.4 1.6 1.4 -0.6 -4 50 60 70 80 90 1.0 0.8 0.6 REMOTE ERROR 0.4 VIN = SQUARE WAVE APPLIED TO VCC WITH NO 0.1μF VCC CAPACITOR 0 0 100 LOCAL ERROR 1.2 0.2 -0.8 -1.0 -6 MAX6648/92 toc06 0.8 TEMPERATURE ERROR (°C) 2 MAX6648/92 toc05 4 1.0 TEMPERATURE ERROR (°C) MAX6648/92 toc04 6 25 50 75 100 125 0.1 1 10 100 1k 10k TEMPERATURE (°C) TEMPERATURE (°C) FREQUENCY (Hz) TEMPERATURE ERROR vs. COMMON-MODE NOISE FREQUENCY TEMPERATURE ERROR vs. DIFFERENTIAL-MODE NOISE FREQUENCY TEMPERATURE ERROR vs. DXP-DXN CAPACITANCE 5 4 3 2 LOCAL ERROR 1 1.0 0.5 0 -0.5 -1.0 0 VIN = 20mVP-P SQUARE WAVE APPLIED TO DXP-DXN -1.5 -1 1 10 100 1k FREQUENCY (Hz) 10k 100k 1 10 100 1k FREQUENCY (Hz) 0 -1 -2 -3 -4 -5 -2.0 -2 100k MAX6648/92 toc09 REMOTE ERROR 6 1.5 1 TEMPERATURE ERROR (°C) 7 2.0 MAX6648/92 toc08 VIN = AC-COUPLED TO DXN VIN = 100mVP-P 8 TEMPERATURE ERROR (°C) MAX6648/92 toc07 9 4 1.5 -1.5 100 0 3.0 MAX6648/92 toc03 500 2.5 TEMPERATURE ERROR (°C) 3.2 MAX6648/92 toc02 3.6 600 OPERATING SUPPLY CURRENT (μA) MAX6648/92 toc01 STANDBY SUPPLY CURRENT (μA) 4.0 TEMPERATURE ERROR (°C) REMOTE TEMPERATURE ERROR vs. REMOTE-DIODE TEMPERATURE OPERATING SUPPLY CURRENT vs. CONVERSION RATE STANDBY SUPPLY CURRENT vs. SUPPLY VOLTAGE TEMPERATURE ERROR (°C) MAX6648/MAX6692 Precision SMBus-Compatible Remote/Local Temperature Sensors with Overtemperature Alarms 10k 100k -6 0.100 1.000 10.000 DXP-DXN CAPACITANCE (nF) _______________________________________________________________________________________ 100.000 Precision SMBus-Compatible Remote/Local Temperature Sensors with Overtemperature Alarms PIN NAME FUNCTION 1 VCC Supply Voltage Input, 3V to 5.5V. Bypass VCC to GND with a 0.1µF capacitor. A 200Ω series resistor is recommended but not required for additional noise filtering. 2 DXP Combined Remote-Diode Current Source and A/D Positive Input for Remote-Diode Channel. DO NOT LEAVE DXP DISCONNECTED; connect DXP to DXN if no remote diode is used. Place a 2200pF capacitor between DXP and DXN for noise filtering. 3 DXN Combined Remote-Diode Current Sink and A/D Negative Input. DXN is internally biased to one diode drop above ground. 4 OVERT 5 GND Overtemperature Alert/Interrupt Output, Open Drain. OVERT is logic low when the temperature is above the software-programmed threshold. Ground SMBus Alert (Interrupt) Output, Open Drain. ALERT asserts when temperature exceeds user-set limits (high or low temperature). ALERT stays asserted until acknowledged by either reading the status register or by successfully responding to an alert response address, provided that the fault condition no longer exists. See the ALERT Interrupts section. 6 ALERT 7 SDA SMBus Serial-Data Input/Output, Open Drain 8 SCLK SMBus Serial-Clock Input Detailed Description The MAX6648/MAX6692 are temperature sensors designed to work in conjunction with a microprocessor or other intelligence in thermostatic, process-control, or monitoring applications. Communication with the MAX6648/MAX6692 occurs through the SMBus-compatible serial interface and dedicated alert pins. ALERT asserts if the measured local or remote temperature is greater than the software-programmed ALERT high limit or less than the ALERT low limit. ALERT also asserts if the remote-sensing diode pins are shorted or unconnected. The overtemperature alarm, OVERT, asserts if the software-programmed OVERT limit is exceeded. OVERT can be connected to fans, a system shutdown, a clock throttle control, or other thermalmanagement circuitry. The MAX6648/MAX6692 convert temperatures to digital data either at a programmed rate or in single conversions. Temperature data is represented as 10 bits plus sign, with the LSB equal to 0.125°C. The “main” temperature data registers (at addresses 00h and 01h) are 8-bit registers that represent the data as 7 bits with the final MSB indicating the diode fault status (Table 1). The remaining 3 bits of temperature data are available in the “extended” registers at addresses 11h and 10h (Table 2). ADC and Multiplexer The averaging ADC integrates over a 60ms period (each channel, typically), with excellent noise rejection. The multiplexer automatically steers bias currents through the remote and local diodes. The ADC and associated circuitry measure each diode’s forward voltage and compute the temperature based on this voltage. Both channels are automatically converted once the conversion process has started, either in free-running or single-shot mode. If one of the two channels is not used, the device still performs both measurements, and the user can ignore the results of the unused chan- Table 1. Main Temperature Data Register Format (00h, 01h) TEMP (°C) DIGITAL OUTPUT 130 0 111 1111 127 0 111 1111 126 0 111 1111 25 0 001 1001 0 0 000 0000