MAX6642ATT90+TG104

EVALUATION KIT AVAILABLE MAX6642 ±1°C, SMBus-Compatible Remote/ Local Temperature Sensor with Overtemperature Alarm General Description Benefits and Features The MAX6642 precise, two-channel digital temperature sensor accurately measures the temperature of its own die and a remote PN junction and reports the temperature data over a 2-wire serial interface. The remote PN junction is typically a substrate PNP transistor on the die of a CPU, ASIC, GPU, or FPGA. The remote PN junction can also be a discrete diode-connected smallsignal transistor. 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 MAX6642 includes an SMBus timeout. The temperature data format is 10 bit with the least significant bit (LSB) corresponding to +0.25°C. The ALERT output asserts when the local or remote overtemperature thresholds are violated. A fault queue may be used to prevent the ALERT output from setting until two consecutive faults have been detected. Measurements can be done autonomously or in a single-shot mode. • Integrated Temperature Sensor Enables Simultaneous Dual Temperature (Remote and Local) Measurements • Remote Accuracy ±1°C • Local Accuracy ±2°C from +60°C to +100°C • Measures Remote Temperature up to +150°C • 0.25°C Resolution • Dual Zone Monitoring Automates Over-Temperature Alarms • Programmable Remote/Local Temperature Thresholds • ALERT Output • Small Footprint • 3mm x 3mm TDFN Package with Exposed Pad • Low Thermal Mass Reduces Measurement Latency • SMBus/I2C Address Hardwired Ordering Information PART TEMP RANGE PIN-PACKAGE MAX6642ATT90-T -40°C to +125°C 6 TDFN-EP* Remote accuracy is ±1°C maximum error between +60°C and +100°C. The MAX6642 operates from -40°C to +125°C, and measures remote temperatures between 0°C and +150°C. The MAX6642 is available in a 6-pin TDFN package with an exposed pad. MAX6642ATT92-T -40°C to +125°C 6 TDFN-EP* MAX6642ATT94-T -40°C to +125°C 6 TDFN-EP* MAX6642ATT96-T -40°C to +125°C 6 TDFN-EP* MAX6642ATT98-T -40°C to +125°C 6 TDFN-EP* MAX6642ATT9A-T -40°C to +125°C 6 TDFN-EP* Applications MAX6642ATT9C-T -40°C to +125°C 6 TDFN-EP* MAX6642ATT9E-T -40°C to +125°C 6 TDFN-EP* Desktop Computers Notebook Computers Servers Thin Clients Test and Measurement Workstations Graphic Cards T = Tape and reel. *EP = Exposed pad. Pin Configuration and Functional Diagram appear at end of data sheet. Typical Operating Circuit 3.3V Selector Guide 0.1µF MEASURED TEMP RANGE TOP MARK MAX6642ATT90-T 0°C to +150°C AFC MAX6642ATT92-T 0°C to +150°C AFD PART MAX6642ATT94-T 0°C to +150°C AFE MAX6642ATT96-T 0°C to +150°C AFF MAX6642ATT98-T 0°C to +150°C AEW MAX6642ATT9A-T 0°C to +150°C AFG MAX6642ATT9C-T 0°C to +150°C AFH MAX6642ATT9E-T 0°C to +150°C SMBus is a trademark of Intel Corp. AFI 19-2920; Rev 5; 11/15 47Ω 10kΩ EACH VCC MAX6642 2200pF SDA DXP SCLK ALERT µP GND DATA CLOCK INTERRUPT TO µP ±1°C, SMBus-Compatible Remote/ Local Temperature Sensor with Overtemperature Alarm MAX6642 Absolute Maximum Ratings All Voltages Referenced to GND VCC ...........................................................................-0.3V to +6V DXP.............................................................-0.3V to (VCC + 0.3V) SCLK, SDA, ALERT ..................................................-0.3V to +6V SDA, ALERT Current ...........................................-1mA to +50mA Continuous Power Dissipation (TA = +70°C) 6-Pin TDFN (derate 24.4mW/°C above +70°C) .........1951mW ESD Protection (all pins, Human Body Model) ................±2000V Junction Temperature ......................................................+150°C Operating Temperature Range .........................-40°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 = -40°C to +125°C, unless otherwise specified. Typical values are at VCC = +3.3V and TA = +25°C.) (Note 1) PARAMETER Supply Voltage SYMBOL CONDITIONS VCC MIN Temperature Resolution Remote Temperature Error VCC = 3.3V Local Temperature Error VCC = 3.3V 5.5 10 Bits +1.0 TRJ = 0°C to +125°C -3.0 +3.0 TRJ = +125°C to +150°C -3.5 +3.5 TA = +60°C to +100°C -2.0 +2.0 TA = 0°C to +125°C -3.0 +3.0 Falling edge of VCC disables ADC 2.4 2.7 VCC falling edge 1.5 POR Threshold Hysteresis 2.0 2.95 SMBus static Operating Current During conversion Average Operating Current 2.4 tCONV Conversion Rate fCONV IRJ V V mV 3 10 µA 0.5 1.0 mA 143 ms 260 Conversion Time °C mV 90 Standby Supply Current °C °C/V 90 Power-On-Reset (POR) Threshold V °C ±0.2 UVLO UNITS 0.25 -1.0 Undervoltage Lockout Hysteresis Remote-Diode Source Current MAX TRJ = +60°C to +100°C, TA = +25°C to +85°C Supply Sensitivity of Temperature Error Undervoltage Lockout Threshold TYP 3.0 µA From stop bit to conversion completion 106 125 High level 80 100 120 Low level 8 10 12 VOL = 0.4V 1 VOL = 0.6V 4 8 Hz µA ALERT Output-Low Sink Current Output-High Leakage Current www.maximintegrated.com VOH = VCC mA 1 µA Maxim Integrated | 2 ±1°C, SMBus-Compatible Remote/ Local Temperature Sensor with Overtemperature Alarm MAX6642 Electrical Characteristics (continued) (VCC = +3.0V to +5.5V, TA = -40°C to +125°C, unless otherwise specified. Typical values are at VCC = +3.3V and TA = +25°C.) (Note 1) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS 0.8 V +1 µA SMBus-COMPATIBLE INTERFACE (SCLK and SDA) Logic Input Low Voltage Logic Input High Voltage Input Leakage Current VIL VIH ILEAK Output Low Sink Current IOL Input Capacitance CIN VCC = 3.0V 2.2 VIN = GND or 5.5V -1 VOL = 0.6V 6 V mA 5 pF SMBus 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 0 SDA low period for interface reset 20 28 50 ns 40 ms All parameters tested at TA = +25°C. 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. www.maximintegrated.com Maxim Integrated | 3 ±1°C, SMBus-Compatible Remote/ Local Temperature Sensor with Overtemperature Alarm MAX6642 Typical Operating Characteristics (VCC = 3.3V, TA = +25°C, unless otherwise noted.) STANDBY SUPPLY CURRENT vs. CLOCK FREQUENCY 4.0 3.5 3.0 2.5 2.0 0.1 1 10 0 100 125 TEMPERATURE ERROR (°C) 1.5 -2 25 50 75 100 REMOTE ERROR 1.0 LOCAL ERROR 0.5 0 -0.5 -1.0 -3 VIN = 100mVP-P SQUARE WAVE APPLIED TO VCC WITH NO BYPASS CAPACITOR -1.5 0.0001 0.001 125 MAX6642 toc04 2.0 MAX 6642 toc03 -1 0.01 0.1 1 10 TEMPERATURE (°C) FREQUENCY (kHz) TEMPERATURE ERROR vs. DXP NOISE FREQUENCY TEMPERATURE ERROR vs. DXP-GND CAPACITANCE 70 REMOTE ERROR 50 40 LOCAL ERROR 20 100 MAX6642 toc06 1.0 TEMPERATURE ERROR (°C) VIN = AC-COUPLED TO DXP VIN = 100mVP-P SQUARE WAVE 60 2.0 MAX6642 toc05 100 0 -1.0 -2.0 -3.0 -4.0 -5.0 10 -6.0 0.01 0.1 1 FREQUENCY (kHz) www.maximintegrated.com 100 TEMPERATURE ERROR vs. POWER-SUPPLY NOISE FREQUENCY 0 0 0.001 75 LOCAL TEMPERATURE ERROR vs. DIE TEMPERATURE 1 30 50 TEMPERATURE (°C) 2 0 25 CLOCK FREQUENCY (kHz) 3 TEMPERATURE ERROR (°C) -2 2N3906 0.01 TEMPERATURE ERROR (°C) -1 -4 1.0 80 0 -3 1.5 90 MAX6642 toc02 1 TEMPERATURE ERROR (°C) 4.5 SUPPLY CURRENT (µA) 2 MAX6642 toc01 5.0 REMOTE TEMPERATURE ERROR vs. REMOTE-DIODE TEMPERATURE 10 100 0.1 1 10 100 DXP-GND CAPACITANCE (nF) Maxim Integrated | 4 ±1°C, SMBus-Compatible Remote/ Local Temperature Sensor with Overtemperature Alarm MAX6642 Pin Description PIN NAME FUNCTION Supply Voltage Input, +3V to +5.5V. Bypass VCC to GND with a 0.1µF capacitor. A 47Ω series resistor is recommended but not required for additional noise filtering. 1 VCC 2 GND Ground 3 DXP Combined Remote-Diode Current Source and ADC Input for Remote-Diode Channel. Place a 2200pF capacitor between DXP and GND for noise filtering. 4 SCLK SMBus Serial-Clock Input. May be pulled up to +5.5V regardless of VCC. 5 SDA SMBus Serial-Data Input/Output, Open Drain. May be pulled up to +5.5V regardless of VCC. 6 ALERT — EP SMBus Alert (Interrupt) Output, Open Drain. ALERT asserts when temperature exceeds user-set limits. See the ALERT Interrupts section. Exposed Pad. Internally connected to GND. Connect to a PCB ground pad for optimal performance. Not intended as an electrical connection point. Detailed Description The MAX6642 is a temperature sensor for local and remote temperature-monitoring applications. Communication with the MAX6642 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 limit. The MAX6642 converts temperatures to digital data either at a programmed rate of eight conversions per second or in single conversions. Temperature data is represented by 8 data bits (at addresses 00h and 01h), with the LSB equal to +1°C and the MSB equal to +128°C. Two additional bits of remote temperature data are available in the “extended” register at address 10h and 11h (Table 2) providing resolution of +0.25°C. ADC and Multiplexer The averaging ADC integrates over a 60ms period (each channel, typ), 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 channel. If the remote-diode channel is unused, connect DXP to GND rather than leaving DXP open. The conversion time per channel (remote and internal) is 125ms. If both channels are being used, then each channel is converted four times per second. If the external conversion-only option is selected, then the www.maximintegrated.com remote temperature is measured eight times per second. The results of the previous conversion are always available, even if the ADC is busy. Low-Power Standby Mode Standby mode reduces the supply current to less than 10µA by disabling the ADC and timing circuitry. Enter standby mode by setting the RUN bit to 1 in the configuration byte register (Table 4). All data is retained in memory, and the SMBus interface is active and listening for SMBus commands. Standby mode is not a shutdown mode. With activity on the SMBus, the device draws more supply current (see the Typical Operating Characteristics). In standby mode, the MAX6642 can be forced to perform ADC conversions through the one-shot command, regardless of the RUN bit status. If a standby command is received while a conversion is in progress, the conversion cycle is truncated, and the data from that conversion is not latched into a temperature register. The previous data is not changed and remains available. Supply-current drain during the 125ms conversion period is 500µA (typ). In standby mode, supply current drops to 3µA (typ). SMBus Digital Interface From a software perspective, the MAX6642 appears as a set of byte-wide registers that contain temperature data, alarm threshold values, and control bits. A standard SMBus-compatible 2-wire serial interface is used to read temperature data and write control bits and alarm threshold data. The MAX6642 employs four standard SMBus protocols: Write Byte, Read Byte, Send Byte, and Receive Byte. (Figures 1, 2, and 3). The shorter Receive Byte protocol allows quicker transfers, provided that the correct data Maxim Integrated | 5 ±1°C, SMBus-Compatible Remote/ Local Temperature Sensor with Overtemperature Alarm MAX6642 WRITE BYTE FORMAT S ADDRESS WR ACK COMMAND 7 BITS ACK DATA 8 BITS ACK P 8 BITS SLAVE ADDRESS: EQUIVALENT TO CHIP-SELECT LINE OF A 3-WIRE INTERFACE 1 DATA BYTE: DATA GOES INTO THE REGISTER SET BY THE COMMAND BYTE (TO SET THRESHOLDS, CONFIGURATION MASKS, AND SAMPLING RATE) READ BYTE FORMAT S ADDRESS WR ACK COMMAND 7 BITS ACK S SLAVE ADDRESS: EQUIVALENT TO CHIP SELECT LINE ADDRESS RD ACK DATA 7 BITS COMMAND BYTE: SELECTS WHICH REGISTER YOU ARE REDING FROM P DATA BYTE: READS FROM THE REGISTER SET BY THE COMMAND BYTE RECEIVE BYTE FORMAT WR ACK COMMAND 7 BITS ACK P S ADDRESS 8 BITS RD ACK DATA 7 BITS /// P 8 BITS COMMAND BYTE: SENDS COMMAND WITH NO DATA, USUALLY USED FOR ONE-SHOT COMMAND S = START CONDITION P = STOP CONDITION /// 8 BITS SLAVE ADDRESS: REPEATED DUE TO CHANGE IN DATAFLOW DIRECTION SEND BYTE FORMAT S ADDRESS 8 BITS DATA BYTE: READS DATA FROM THE REGISTER COMMANDED BY THE LAST READ BYTE OR WRITE BYTE TRANSMISSION; ALSO USED FOR SMBUS ALERT RESPONSE RETURN ADDRESS SHADED = SLAVE TRANSMISSION /// = NOT ACKNOWLEDGED Figure 1. SMBus Protocols A B tLOW C D E F G tHIGH H I J K L M SMBCLK SMBDATA tSU:STA tHD:STA A = START CONDITION B = MSB OF ADDRESS CLOCKED INTO SLAVE C = LSB OF ADDRESS CLOCKED INTO SLAVE D = R/W BIT CLOCKED INTO SLAVE tSU:STO tSU:DAT E = SLAVE PULLS SMBDATA LINE LOW F = ACKNOWLEDGE BIT CLOCKED INTO MASTER G = MSB OF DATA CLOCKED INTO SLAVE H = LSB OF DATA CLOCKED INTO SLAVE tBUF I = SLAVE PULLS DATA LINE LOW J = ACKNOWLEDGE CLOCKED INTO MASTER K = ACKNOWLEDGE CLOCK PULSE L = STOP CONDITION M = NEW START CONDITION Figure 2. SMBus Write Timing Diagram www.maximintegrated.com Maxim Integrated | 6 ±1°C, SMBus-Compatible Remote/ Local Temperature Sensor with Overtemperature Alarm MAX6642 Table 1. Main Temperature Register (High Byte) Data Format register was previously selected by a Write Byte instruction. Use caution when using the shorter protocols in multimaster systems, as a second master could overwrite the command byte without informing the first master. Read temperature data from the read internal temperature (00h) and read external temperature (01h) registers. The temperature data format for these registers is 8 bits for each channel, with the LSB representing +1°C (Table 1). Read the additional bits from the read extended temperature byte register (10h, 11h), which extends the data to 10 bits and the resolution to +0.25°C per LSB (Table 2). When a conversion is complete, the main temperature register and the extended temperature register are updated. Two registers store ALERT threshold values—one each for the local and remote channels. If either measured temperature equals or exceeds the corresponding ALERT threshold value, the ALERT interrupt asserts unless the ALERT bit is masked. The power-on-reset (POR) state of the local ALERT THIGH register is +70°C (0100 0110). The POR state of the remote ALERT THIGH register is +120°C (0111 1000). tHIGH C D E 0 111 1111 126.00 0 111 1110 25 0 001 1001 0.00 0 000 0000