TMP411 SBOS383A − FEBRUARY 2007 ±1°C Remote and Local TEMPERATURE SENSOR with N-Factor and Series Resistance Correction FEATURES DESCRIPTION D D D D D D D D D The TMP411 is a remote temperature sensor monitor with a built-in local temperature sensor. The remote temperature sensor diode-connected transistors are typically low-cost, NPN- or PNP-type transistors or diodes that are an integral part of microcontrollers, microprocessors, or FPGAs. D D D ±1°C REMOTE DIODE SENSOR ±1°C LOCAL TEMPERATURE SENSOR PROGRAMMABLE NON-IDEALITY FACTOR SERIES RESISTANCE CANCELLATION ALERT FUNCTION PROGRAMMABLE RESOLUTION: 9 to 12 Bits PROGRAMMABLE THRESHOLD LIMITS TWO-WIRE/SMBus SERIAL INTERFACE MINIMUM AND MAXIMUM TEMPERATURE MONITORS MULTIPLE INTERFACE ADDRESSES ALERT/THERM2 PIN CONFIGURATION DIODE FAULT DETECTION Remote accuracy is ±1°C for multiple IC manufacturers, with no calibration needed. The Two-Wire serial interface accepts SMBus write byte, read byte, send byte, and receive byte commands to program the alarm thresholds and to read temperature data. Features that are included in the TMP411 are: series resistance cancellation, programmable non-ideality factor, programmable resolution, programmable threshold limits, minimum and maximum temperature monitors, wide remote temperature measurement range (up to +150°C), diode fault detection, and temperature alert function. APPLICATIONS D D D D D D D D LCD/DLP/LCOS PROJECTORS SERVERS INDUSTRIAL CONTROLLERS CENTRAL OFFICE TELECOM EQUIPMENT DESKTOP AND NOTEBOOK COMPUTERS STORAGE AREA NETWORKS (SAN) V+ INDUSTRIAL AND MEDICAL 1 V+ EQUIPMENT 5 GND PROCESSOR/FPGA TEMPERATURE MONITORING The TMP411 is available in both MSOP-8 and SO-8 (available Q1 2007) packages. 4 6 TMP411 Interrupt Configuration THERM ALERT/THERM2 Consecutive Alert Configuration Register Remote Temp High Limit N−Factor Correction Status Register Remote THERM Limit Remote Temp Low Limit Local Temperature Register TL THERM Hysteresis Register Local Temp High Limit Local THERM Limit Temperature Comparators Conversion Rate Register Local Temperature Min/Max Register D+ 2 3 Local Temp Low Limit Remote Temperature Register TR Remote Temperature Min/Max Register Manufacturer ID Register D− Device ID Register Configuration Register Resolution Register 8 SCL Bus Interface 7 Pointer Register SDA Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet. DLP is a registered trademark of Texas Instruments. SMBus is a trademark of Intel Corp. All other trademarks are the property of their respective owners. Copyright 2006−2007, Texas Instruments Incorporated ! ! www.ti.com "#$$ www.ti.com SBOS383A − FEBRUARY 2007 ABSOLUTE MAXIMUM RATINGS(1) Power Supply, VS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.0V Input Voltage, pins 2, 3, 4 only . . . . . . . . . . . . . −0.5V to VS + 0.5V Input Voltage, pins 6, 7, 8 only . . . . . . . . . . . . . . . . . . . −0.5V to 7V Input Current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10mA Operating Temperature Range . . . . . . . . . . . . . . . −55°C to +127°C Storage Temperature Range . . . . . . . . . . . . . . . . . −60°C to +130°C Junction Temperature (TJ max) . . . . . . . . . . . . . . . . . . . . . . +150°C ESD Rating: Human Body Model (HBM) . . . . . . . . . . . . . . . . . . . . . . . 3000V Charged Device Model (CDM) . . . . . . . . . . . . . . . . . . . . 1000V Machine Model (MM) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 200V (1) Stresses above these ratings may cause permanent damage. Exposure to absolute maximum conditions for extended periods may degrade device reliability. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those specified is not supported. This integrated circuit can be damaged by ESD. Texas Instruments recommends that all integrated circuits be handled with appropriate precautions. Failure to observe proper handling and installation procedures can cause damage. ESD damage can range from subtle performance degradation to complete device failure. Precision integrated circuits may be more susceptible to damage because very small parametric changes could cause the device not to meet its published specifications. ORDERING INFORMATION(1) PACKAGE DESIGNATOR PACKAGE MARKING PRODUCT DESCRIPTION I2C ADDRESS PACKAGE-LEAD 411A Remote Junction Temperature Sensor 100 1100 MSOP-8 SO-8(2) DGK TMP411A D T411A 411B Remote Junction Temperature Sensor 100 1101 MSOP-8 SO-8(2) DGK TMP411B D T411B (1) For the most current package and ordering information see the Package Option Addendum at the end of this document, or see the TI web site at www.ti.com. (2) Available Q1 2007. PIN CONFIGURATION PIN ASSIGNMENTS Top View MSOP, SO TMP411 2 V+ 1 8 SCL D+ 2 7 SDA D− 3 6 ALERT/THERM2 THERM 4 5 GND PIN NAME 1 V+ Positive supply (2.7V to 5.5V) DESCRIPTION 2 D+ Positive connection to remote temperature sensor 3 D− Negative connection to remote temperature sensor 4 THERM 5 GND 6 ALERT/THERM2 Alert (reconfigurable as second thermal flag), active low, open-drain; requires pull-up resistor to V+ 7 SDA Serial data line for SMBus, open-drain; requires pull-up resistor to V+ 8 SCL Serial clock line for SMBus, open-drain; requires pull-up resistor to V+ Thermal flag, active low, open-drain; requires pull-up resistor to V+ Ground "#$$ www.ti.com SBOS383A − FEBRUARY 2007 ELECTRICAL CHARACTERISTICS At TA = −40°C to +125°C and VS = 2.7V to 5.5V, unless otherwise noted. TMP411 PARAMETERS TYP MAX UNITS TA = −40°C to +125°C TA = +15°C to +85°C, VS = 3.3V TA = +15°C to +75°C, TD = −40°C to +150°C, VS = 3.3V TA = −40°C to +100°C, TD = −40°C to +150°C, VS = 3.3V TA = −40°C to +125°C, TD = −40°C to +150°C ±1.25 ±0.0625 ±0.0625 ±1 ±3 ±2.5 ±1 ±1 ±3 ±5 °C °C °C °C °C VS = 2.7V to 5.5V ±0.2 ±0.5 °C/V 115 125 ms 12 Bits Bits CONDITIONS MIN TEMPERATURE ERROR Local Temperature Sensor Remote Temperature Sensor(1) TELOCAL TEREMOTE vs Supply Local/Remote TEMPERATURE MEASUREMENT Conversion Time (per channel) Resolution Local Temperature Sensor (programmable) Remote Temperature Sensor Remote Sensor Source Currents High Medium High Medium Low Low Remote Transistor Ideality Factor SMBus INTERFACE Logic Input High Voltage (SCL, SDA) Logic Input Low Voltage (SCL, SDA) Hysteresis SMBus Output Low Sink Current Logic Input Current SMBus Input Capacitance (SCL, SDA) SMBus Clock Frequency SMBus Timeout SCL Falling Edge to SDA Valid Time DIGITAL OUTPUTS Output Low Voltage High-Level Output Leakage Current ALERT/THERM2 Output Low Sink Current THERM Output Low Sink Current POWER SUPPLY Specified Voltage Range Quiescent Current Undervoltage Lock Out Power-On Reset Threshold 105 9 12 Series Resistance 3kΩ Max η TMP411 Optimized Ideality Factor VIH VIL µA µA µA µA 120 60 12 6 1.008 2.1 0.8 500 6 −1 +1 3 25 VOL IOH VS IQ IOUT = 6mA VOUT = VS ALERT/THERM2 Forced to 0.4V THERM Forced to 0.4V 30 3.4 35 1 0.15 0.1 0.4 1 V µA mA mA 5.5 30 475 10 2.6 2.3 V µA µA µA µA µA V V +125 +130 °C °C 6 6 2.7 0.0625 Conversions per Second Eight Conversions per Second Serial Bus Inactive, Shutdown Mode Serial Bus Active, fS = 400kHz, Shutdown Mode Serial Bus Active, fS = 3.4MHz, Shutdown Mode 2.3 POR TEMPERATURE RANGE Specified Range Storage Range Thermal Resistance MSOP-8, SO-8 V V mV mA µA pF MHz ms µs 28 400 3 90 350 2.4 1.6 −40 −60 150 °C/W (1) Tested with less than 5Ω effective series resistance and 100pF differential input capacitance. 3 "#$$ www.ti.com SBOS383A − FEBRUARY 2007 TYPICAL CHARACTERISTICS At TA = +25°C and VS = 5.0V, unless otherwise noted. LOCAL TEMPERATURE ERROR vs TEMPERATURE REMOTE TEMPERATURE ERROR vs TEMPERATURE 2 3.0 VS = 3.3V TREMOTE = +25_ C 30 Typical Units Shown η = 1.008 1 0 −1 −2 −3 −50 −25 2.0 1.0 0 − 1.0 − 2.0 − 3.0 0 25 50 75 100 125 − 50 − 25 Ambient Temperature, TA (_ C) 40 1.5 Remote Temperature Error (_ C) 2.0 R −GND 0 R −VS −40 −60 100 125 VS = 2.7V 1.0 0.5 0 VS = 5.5V − 0.5 − 1.0 − 1.5 5 10 15 20 25 30 0 500 1000 1500 Leakage Resistance (MΩ ) 2000 2500 3000 3500 RS (Ω) Figure 3. Figure 4. REMOTE TEMPERATURE ERROR vs SERIES RESISTANCE (GND Collector−Connected Transistor, 2N3906 PNP) REMOTE TEMPERATURE ERROR vs DIFFERENTIAL CAPACITANCE 2.0 3 1.5 VS = 2.7V 1.0 0.5 VS = 5.5V 0 − 0.5 − 1.0 − 1.5 Remote Temperature Error (_C) Remote Temperature Error (_ C) 75 − 2.0 0 2 1 0 −1 −2 −3 − 2.0 0 500 1000 1500 2000 RS (Ω) Figure 5. 4 50 REMOTE TEMPERATURE ERROR vs SERIES RESISTANCE (Diode−Connected Transistor, 2N3906 PNP) 60 −20 25 Figure 2. REMOTE TEMPERATURE ERROR vs LEAKAGE RESISTANCE 20 0 Ambient Temperature, TA (_ C) Figure 1. Remote Temperature Error (_C) 50 Units Shown VS = 3.3V Local Temperature Error (_C) Remote Temperature Error (_C) 3 2500 3000 3500 0 0.5 1.0 1.5 2.0 Capacitance (nF) Figure 6. 2.5 3.0 "#$$ www.ti.com SBOS383A − FEBRUARY 2007 TYPICAL CHARACTERISTICS (continued) At TA = +25°C and VS = 5.0V, unless otherwise noted. TEMPERATURE ERROR vs POWER−SUPPLY NOISE FREQUENCY 25 500 Local 100mVPP Noise Remote 100mVPP Noise Local 250mVPP Noise Remote 250mVPP Noise 20 15 10 450 400 350 5 I Q (µA) Temperature Error (_C) QUIESCENT CURRENT vs CONVERSION RATE 0 −5 300 200 −10 150 −15 100 −20 50 −25 0 5 10 0 0.0625 15 VS = 5.5V 250 VS = 2.7V 0.125 Frequency (MHz) 0.25 0.5 1 2 4 8 Conversion Rate (conversions/sec) Figure 7. Figure 8. SHUTDOWN QUIESCENT CURRENT vs SUPPLY VOLTAGE SHUTDOWN QUIESCENT CURRENT vs SCL CLOCK FREQUENCY 500 8 450 7 400 6 5 300 250 IQ (µA) IQ (µA) 350 VS = 5.5V 200 4 3 150 2 100 1 50 VS = 3.3V 0 1k 10k 100k 1M SCL CLock Frequency (Hz) Figure 9. 10M 0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 VS (V) Figure 10. 5 "#$$ www.ti.com SBOS383A − FEBRUARY 2007 (ALERT). Additional thermal limits can be programmed into the TMP411 and used to trigger another flag (THERM) that can be used to initiate a system response to rising temperatures. APPLICATIONS INFORMATION The TMP411 is a dual-channel digital temperature sensor that combines a local die temperature measurement channel and a remote junction temperature measurement channel in a single MSOP-8 or SO-8 package. The TMP411 is Two-Wire- and SMBus interface-compatible and is specified over a temperature range of −40°C to +125°C. The TMP411 contains multiple registers for holding configuration information, temperature measurement results, temperature comparator maximum/minimum limits, and status information. User-programmed high and low temperature limits stored in the TMP401 can be used to monitor local and remote temperatures to trigger an over/under temperature alarm The TMP411 requires only a transistor connected between D+ and D− for proper remote temperature sensing operation. The SCL and SDA interface pins require pull-up resistors as part of the communication bus, while ALERT and THERM are open-drain outputs that also need pull−up resistors. ALERT and THERM may be shared with other devices if desired for a wired-OR implementation. A 0.1µF power-supply bypass capacitor is recommended for good local bypassing. Figure 11 shows a typical configuration for the TMP411. +5V 0.1µF Transistor−connected configuration(1) : 1 Series Resistance RS (2) V+ SCL RS(2) 2 CDIFF(3) 3 D+ 10kΩ (typ) 10kΩ (typ) 10kΩ (typ) 10kΩ (typ) 8 TMP411 SDA 7 D− ALERT/THERM2 THERM SMBus Controller 6 4 Fan Controller GND Diode−connected configuration(1): RS 5 (2) RS(2) CDIFF(3) NOTES: (1) Diode−connected configuration provides better settling time. Transistor−connected configuration provides better series resistance cancellation. (2) RS should be < 1.5kΩ in most applications. (3) CDIFF should be < 1000pF in most applications. Figure 11. Basic Connections 6 "#$$ www.ti.com SBOS383A − FEBRUARY 2007 SERIES RESISTANCE CANCELLATION Series resistance in an application circuit that typically results from printed circuit board (PCB) trace resistance and remote line length (see Figure 11) is automatically cancelled by the TMP411, preventing what would otherwise result in a temperature offset. for ambient temperatures ranging from −40°C to +125°C. Parameters in the Absolute Maximum Ratings table must be observed. Table 1. Temperature Data Format (Local and Remote Temperature High Bytes) A total of up to 3kΩ of series line resistance is cancelled by the TMP411, eliminating the need for additional characterization and temperature offset correction. See the two Remote Temperature Error vs Series Resistance typical characteristics curves for details on the effect of series resistance and power-supply voltage on sensed remote temperature error. DIFFERENTIAL INPUT CAPACITANCE The TMP411 tolerates differential input capacitance of up to 1000pF with minimal change in temperature error. The effect of capacitance on sensed remote temperature error is illustrated in typical characteristic Remote Temperature Error vs Differential Capacitance. TEMPERATURE MEASUREMENT DATA Temperature measurement data is taken over a default range of 0°C to +127°C for both local and remote locations. Measurements from −55°C to +150°C can be made both locally and remotely by reconfiguring the TMP411 for the extended temperature range. To change the TMP411 configuration from the standard to the extended temperature range, switch bit 2 (RANGE) of the Configuration Register from low to high. Temperature data resulting from conversions within the default measurement range is represented in binary form, as shown in Table 1, Standard Binary column. Note that any temperature below 0°C results in a data value of zero (00h). Likewise, temperatures above +127°C result in a value of 127 (7Fh). The device can be set to measure over an extended temperature range by changing bit 2 of the Configuration Register from low to high. The change in measurement range and data format from standard binary to extended binary occurs at the next temperature conversion. For data captured in the extended temperature range configuration, an offset of 64 (40h) is added to the standard binary value, as shown in Table 1, Extended Binary column. This configuration allows measurement of temperatures below 0°C. Note that binary values corresponding to temperatures as low as −64°C, and as high as +191°C are possible; however, most temperature sensing diodes only measure with the range of −55°C to +150°C. Additionally, the TMP411 is rated only LOCAL/REMOTE TEMPERATURE REGISTER HIGH BYTE VALUE (+1°C RESOLUTION) STANDARD BINARY EXTENDED BINARY TEMP (°C) BINARY HEX BINARY HEX −64 0000 0000 00 0000 0000 00 −50 0000 0000 00 0000 1110 0E −25 0000 0000 00 0010 0111 27 0 0000 0000 00 0100 0000 40 1 0000 0001 01 0100 0001 41 5 0000 0101 05 0100 0101 45 10 0000 1010 0A 0100 1010 4A 25 0001 1001 19 0101 1001 59 50 0011 0010 32 0111 0010 72 75 0100 1011 4B 1000 1011 8B 100 0110 0100 64 1010 0100 A4 125 0111 1101 7D 1011 1101 BD 127 0111 1111 7F 1011 1111 BF 150 0111 1111 7F 1101 0110 D6 175 0111 1111 7F 1110 1111 EF 191 0111 1111 7F 1111 1111 FF NOTE: Whenever changing between standard and extended temperature ranges, be aware that the temperatures stored in the temperature limit registers are NOT automatically reformatted to correspond to the new temperature range format. These temperature limit values must be reprogrammed in the appropriate binary or extended binary format. Both local and remote temperature data use two bytes for data storage. The high byte stores the temperature with 1°C resolution. The second or low byte stores the decimal fraction value of the temperature and allows a higher measurement resolution; see Table 2. The measurement resolution for the remote channel is 0.0625°C, and is not adjustable. The measurement resolution for the local channel is adjustable; it can be set for 0.5°C, 0.25°C, 0.125°C, or 0.0625°C by setting the RES1 and RES0 bits of the Resolution Register; see the Resolution Register section. 7 "#$$ www.ti.com SBOS383A − FEBRUARY 2007 Table 2. Decimal Fraction Temperature Data Format (Local and Remote Temperature Low Bytes) REMOTE TEMPERATURE REGISTER LOW BYTE VALUE LOCAL TEMPERATURE REGISTER LOW BYTE VALUE 0.0625°C RESOLUTION TEMP (°C) STANDARD AND EXTENDED BINARY 0.0000 0000 0000 0.0625 0.1250 0.5°C RESOLUTION HEX STANDARD AND EXTENDED BINARY 00 0000 0000 0001 0000 10 0010 0000 20 0.1875 0011 0000 0.2500 0.3125 0.3750 0.25°C RESOLUTION HEX STANDARD AND EXTENDED BINARY 00 0000 0000 0000 0000 00 0000 0000 00 30 0000 0000 0100 0000 40 0101 0000 50 0110 0000 0.4375 0.5000 0.5625 0.125°C RESOLUTION HEX STANDARD AND EXTENDED BINARY 00 0000 0000 0000 0000 00 0000 0000 00 00 0000 0000 0000 0000 00 0000 0000 00 60 0000 0000 0111 0000 70 1000 0000 80 1001 0000 0.6250 0.6875 0.0625°C RESOLUTION HEX STANDARD AND EXTENDED BINARY HEX 00 0000 0000 00 0000 0000 00 0001 0000 10 0010 0000 20 0010 0000 20 00 0010 0000 20 0011 0000 30 0100 0000 40 0100 0000 40 0100 0000 40 0100 0000 40 0100 0000 40 0101 0000 50 00 0100 0000 40 0110 0000 60 0110 0000 60 0000 0000 00 0100 0000 40 0110 0000 60 0111 0000 70 1000 0000 80 1000 0000 80 1000 0000 80 1000 0000 80 90 1000 0000 80 1000 0000 80 1000 0000 80 1001 0000 90 1010 0000 A0 1000 0000 80 1000 0000 80 1010 0000 A0 1010 0000 A0 1011 0000 B0 1000 0000 80 1000 0000 80 1010 0000 A0 1011 0000 B0 0.7500 1100 0000 C0 1000 0000 80 1100 0000 C0 1100 0000 C0 1100 0000 C0 0.8125 1101 0000 D0 1000 0000 80 1100 0000 C0 1100 0000 C0 1101 0000 D0 0.8750 1110 0000 E0 1000 0000 80 1100 0000 C0 1110 0000 E0 1110 0000 E0 0.9385 1111 0000 F0 1000 0000 80 1100 0000 C0 1110 0000 E0 1111 0000 F0 REGISTER INFORMATION The TMP411 contains multiple registers for holding configuration information, temperature measurement results, temperature comparator maximum/minimum, limits, and status information. These registers are described in Figure 12 and Table 3. POINTER REGISTER Figure 12 shows the internal register structure of the TMP411. The 8-bit Pointer Register is used to address a given data register. The Pointer Register identifies which of the data registers should respond to a read or write command on the Two-Wire bus. This register is set with every write command. A write command must be issued to set the proper value in the Pointer Register before executing a read command. Table 3 describes the pointer address of the registers available in the TMP411. The power-on reset (POR) value of the Pointer Register is 00h (0000 0000b). 8 Pointer Register Local and Remote Temperature Registers Local and Remote Limit Registers SDA THERM Hysteresis Register Status Register Configuration Register Resolution Register I/O Control Interface Conversion Rate Register Consecutive Alert Register Identification Registers Local Temperature Min/Max Remote Temperature Min/Max Figure 12. Internal Register Structure SCL "#$$ www.ti.com SBOS383A − FEBRUARY 2007 Table 3. Register Map POINTER ADDRESS (HEX) READ WRITE POWER-ON RESET (HEX) D7 D6 D5 D4 D3 D2 D1 D0 REGISTER DESCRIPTIONS 00 NA(1) 00 LT11 LT10 LT9 LT8 LT7 LT6 LT5 LT4 Local Temperature (High Byte) 01 NA 00 RT11 RT10 RT9 RT8 RT7 RT6 RT5 RT4 Remote Temperature (High Byte) 02 NA XX BUSY LHIGH LLOW RHIGH RLOW OPEN RTHRM LTHRM Status Register 03 09 00 MASK1 SD AL/TH 0 0 RANGE 0 0 Configuration Register 04 0A 08 0 0 0 0 R3 R2 R1 R0 Conversion Rate Register BIT DESCRIPTIONS 05 0B 55 LTH11 LTH10 LTH9 LTH8 LTH7 LTH6 LTH5 LTH4 Local Temperature High Limit (High Byte) 06 0C 00 LTL11 LTL10 LTL9 LTL8 LTL7 LTL6 LTL5 LTL4 Local Temperature Low Limit (High Byte) 07 0D 55 RTH11 RTH10 RTH9 RTH8 RTH7 RTH6 RTH5 RTH4 Remote Temperature High Limit (High Byte) 08 0E 00 RTL11 RTL10 RTL9 RTL8 RTL7 RTL6 RTL5 RTL4 Remote Temperature Low Limit (High Byte) 10 NA 00 RT3 RT2 RT1 RT0 0 0 0 0 Remote Temperature (Low Byte) 13 13 00 RTH3 RTH2 RTH1 RTH0 0 0 0 0 Remote Temperature High Limit (Low Byte) 14 14 00 RTL3 RTL2 RTL1 RTL0 0 0 0 0 Remote Temperature Low Limit (Low Byte) 15 NA 00 LT3 LT2 LT1 LT0 0 0 0 0 Local Temperature (Low Byte) 16 16 00 LTH3 LTH2 LTH1 LTH0 0 0 0 0 Local Temperature High Limit (Low Byte) 17 17 00 LTL3 LTL2 LTL1 LTL0 0 0 0 0 Local Temperature Low Limit (Low Byte) 18 18 00 NC7 NC6 NC5 NC4 NC3 NC2 NC1 NC0 N-factor Correction 19 19 55 RTHL11 RTHL10 RTHL9 RTHL8 RTHL7 RTHL6 RTHL5 RTHL4 Remote THERM Limit 1A 1A 1C 0 0 0 1 1 1 RES1 RES0 Resolution Register 20 20 55 LTHL11 LTHL10 LTHL9 LTHL8 LTHL7 LTHL6 LTHL5 LTHL4 Local THERM Limit 21 21 0A TH11 TH10 TH9 TH8 TH7 TH6 TH5 TH4 THERM Hysteresis 22 22 80 TO_EN 0 0 0 C2 C1 C0 0 Consecutive Alert Register 30 30 FF LMT11 LMT10 LMT9 LMT8 LMT7 LMT6 LMT5 LMT4 Local Temperature Minimum (High Byte) 31 31 F0 LMT3 LMT2 LMT1 LMT0 0 0 0 0 Local Temperature Minimum (Low Byte) 32 32 00 LXT11 LXT10 LXT9 LXT8 LXT7 LXT6 LXT5 LXT4 Local Temperature Maximum (High Byte) 33 33 00 LXT3 LXT2 LXT1 LXT0 0 0 0 0 Local Temperature Maximum (Low Byte) 34 34 FF RMT11 RMT10 RMT9 RMT8 RMT7 RMT6 RMT5 RMT4 Remote Temperature Minimum (High Byte) 35 35 F0 RMT3 RMT2 RMT1 RMT0 0 0 0 0 Remote Temperature Minimum (Low Byte) 36 36 00 RXT11 RXT10 RXT9 RXT8 RXT7 RXT6 RXT5 RXT4 Remote Temperature Maximum (High Byte) 37 37 00 RXT3 RXT2 RXT1 RXT0 0 0 0 0 Remote Temperature Maximum (Low Byte) NA FC XX X(2) X X X X X X X Software Reset FE NA 55 0 1 0 1 0 1 0 1 Manufacturer ID FF NA 11 0 0 0 1 0 0 0 1 Device ID (1) NA = not applicable; register is write- or read-only. (2) X = indeterminate state. 9 "#$$ www.ti.com SBOS383A − FEBRUARY 2007 TEMPERATURE REGISTERS The TMP411 has four 8-bit registers that hold temperature measurement results. Both the local channel and the remote channel have a high byte register that contains the most significant bits (MSBs) of the temperature ADC result and a low byte register that contains the least significant bits (LSBs) of the temperature ADC result. The local channel high byte address is 00h; the local channel low byte address is 15h. The remote channel high byte is at address 01h; the remote channel low byte address is 10h. These registers are read-only and are updated by the ADC each time a temperature measurement is completed. The TMP411 contains circuitry to assure that a low byte register read command returns data from the same ADC conversion as the immediately preceding high byte read command. This assurance remains valid only until another register is read. For proper operation, the high byte of a temperature register should be read first. The low byte register should be read in the next read command. The low byte register may be left unread if the LSBs are not needed. Alternatively, the temperature registers may be read as a 16-bit register by using a single two-byte read command from address 00h for the local channel result or from address 01h for the remote channel result. The high byte will be output first, followed by the low byte. Both bytes of this read operation will be from the same ADC conversion. The power-on reset value of both temperature registers is 00h. LIMIT REGISTERS The TMP411 has 11 registers for setting comparator limits for both the local and remote measurement channels. These registers have read and write capability. The High and Low Limit Registers for both channels span two registers, as do the temperature registers. The local temperature high limit is set by writing the high byte to pointer address 0Bh and writing the low byte to pointer address 16h, or by using a single two-byte write command (high byte first) to pointer address 0Bh. The local temperature high limit is obtained by reading the high byte from pointer address 05h and the low byte from pointer address 16h. The power-on reset value of the local temperature high limit is 55h/00h (+85°C in standard temperature mode; +21°C in extended temperature mode). Similarly, the local temperature low limit is set by writing the high byte to pointer address 0Ch and writing the low byte to pointer address 17h, or by using a single two-byte write command to pointer address 0Ch. The local temperature low limit is read by reading the high byte from 10 pointer address 06h and the low byte from pointer address 17h, or by using a two-byte read from pointer address 06h. The power-on reset value of the local temperature low limit register is 00h/00h (0°C in standard temperature mode; −64°C in extended mode). The remote temperature high limit is set by writing the high byte to pointer address 0Dh and writing the low byte to pointer address 13h, or by using a two-byte write command to pointer address 0Dh. The remote temperature high limit is obtained by reading the high byte from pointer address 07h and the low byte from pointer address 13h, or by using a two-byte read command from pointer address 07h. The power-on reset value of the Remote Temperature High Limit Register is 55h/00h (+85°C in standard temperature mode; +21°C in extended temperature mode). The remote temperature low limit is set by writing the high byte to pointer address 0Eh and writing the low byte to pointer address 14h, or by using a two-byte write to pointer address 0Eh. The remote temperature low limit is read by reading the high byte from pointer address 08h and the low byte from pointer address 14h, or by using a two-byte read from pointer address 08h. The power-on reset value of the Remote Temperature Low Limit Register is 00h/00h (0°C in standard temperature mode; −64°C in extended mode). The TMP411 also has a THERM limit register for both the local and the remote channels. These registers are eight bits and allow for THERM limits set to 1°C resolution. The local channel THERM limit is set by writing to pointer address 20h. The remote channel THERM limit is set by writing to pointer address 19h. The local channel THERM limit is obtained by reading from pointer address 20h; the remote channel THERM limit is read by reading from pointer address 19h. The power-on reset value of the THERM limit registers is 55h (+85°C in standard temperature mode; +21°C in extended temperature mode). The THERM limit comparators also have hysteresis. The hysteresis of both comparators is set by writing to pointer address 21h. The hysteresis value is obtained by reading from pointer address 21h. The value in the Hysteresis Register is an unsigned number (always positive). The power-on reset value of this register is 0Ah (+10°C). Whenever changing between standard and extended temperature ranges, be aware that the temperatures stored in the temperature limit registers are NOT automatically reformatted to correspond to the new temperature range format. These values must be reprogrammed in the appropriate binary or extended binary format. "#$$ www.ti.com SBOS383A − FEBRUARY 2007 STATUS REGISTER The TMP411 has a Status Register to report the state of the temperature comparators. Table 4 shows the Status Register bits. The Status Register is read-only and is read by reading from pointer address 02h. The BUSY bit reads as ‘1’ if the ADC is making a conversion. It reads as ‘0’ if the ADC is not converting. The OPEN bit reads as ‘1’ if the remote transistor was detected as open since the last read of the Status Register. The OPEN status is only detected when the ADC is attempting to convert a remote temperature. The RTHRM bit reads as ‘1’ if the remote temperature has exceeded the remote THERM limit and remains greater than the remote THERM limit less the value in the shared Hysteresis Register; see Figure 17. The LTHRM bit reads as ‘1’ if the local temperature has exceeded the local THERM limit and remains greater than the local THERM limit less the value in the shared Hysteresis Register; see Figure 17. The LHIGH and RHIGH bit values depend on the state of the AL/TH bit in the Configuration Register. If the AL/TH bit is ‘0’, the LHIGH bit reads as ‘1’ if the local high limit was exceeded since the last clearing of the Status Register. The RHIGH bit reads as ‘1’ if the remote high limit was exceeded since the last clearing of the Status Register. If the AL/TH bit is ‘1’, the remote high limit and the local high limit are used to implement a THERM2 function. LHIGH reads as ‘1’ if the local temperature has exceeded the local high limit and remains greater than the local high limit less the value in the Hysteresis Register. The RHIGH bit reads as ‘1’ if the remote temperature has exceeded the remote high limit and remains greater than the remote high limit less the value in the Hysteresis Register. The LLOW and RLOW bits are not affected by the AL/TH bit. The LLOW bit reads as ‘1’ if the local low limit was exceeded since the last clearing of the Status Register. The RLOW bit reads as ‘1’ if the remote low limit was exceeded since the last clearing of the Status Register. The values of the LLOW, RLOW, and OPEN (as well as LHIGH and RHIGH when AL/TH is ‘0’) are latched and will read as ‘1’ until the Status Register is read or a device reset occurs. These bits are cleared by reading the Status Register, provided that the condition causing the flag to be set no longer exists. The values of BUSY, LTHRM, and RTHRM (as well as LHIGH and RHIGH when AL/TH is ‘1’) are not latched and are not cleared by reading the Status Register. They always indicate the current state, and are updated appropriately at the end of the corresponding ADC conversion. Clearing the Status Register bits does not clear the state of the ALERT pin; an SMBus alert response address command must be used to clear the ALERT pin. The TMP411 NORs LHIGH, LLOW, RHIGH, RLOW, and OPEN, so a status change for any of these flags from ‘0’ to ‘1’ automatically causes the ALERT pin to go low (only applies when the ALERT/THERM2 pin is configured for ALERT mode). Table 4. Status Register Format STATUS REGISTER (Read = 02h, Write = NA) BIT # BIT NAME POR VALUE D7 D6 D5 D4 D3 D2 D1 D0 BUSY LHIGH LLOW RHIGH RLOW OPEN RTHRM LTHRM 0(1) 0 0 0 0 0 0 0 (1) The BUSY bit will change to ‘1’ almost immediately (<< 100µs) following power-up, as the TMP411 begins the first temperature conversion. It will be high whenever the TMP411 is converting a temperature reading. 11 "#$$ www.ti.com SBOS383A − FEBRUARY 2007 CONFIGURATION REGISTER The Configuration Register sets the temperature range, controls shutdown mode, and determines how the ALERT/THERM2 pin functions. The Configuration Register is set by writing to pointer address 09h and read by reading from pointer address 03h. The MASK bit (bit 7) enables or disables the ALERT pin output if AL/TH = 0. If AL/TH = 1 then the MASK bit has no effect. If MASK is set to ‘0’, the ALERT pin goes low when one of the temperature measurement channels exceeds its high or low limits for the chosen number of consecutive conversions. If the MASK bit is set to ‘1’, the TMP411 retains the ALERT pin status, but the ALERT pin will not go low. The shutdown (SD) bit (bit 6) enables or disables the temperature measurement circuitry. If SD = 0, the TMP411 converts continuously at the rate set in the conversion rate register. When SD is set to ‘1’, the TMP411 immediately stops converting and enters a shutdown mode. When SD is set to ‘0’ again, the TMP411 resumes continuous conversions. The AL/TH bit (bit 5) controls whether the ALERT pin functions in ALERT mode or THERM2 mode. If AL/TH = 0, the ALERT pin operates as an interrupt pin. In this mode, the ALERT pin goes low after the set number of consecutive out-of-limit temperature measurements occur. If AL/TH = 1, the ALERT/THERM2 pin implements a THERM function (THERM2). In this mode, THERM2 functions similar to the THERM pin except that the local high limit and remote high limit registers are used for the thresholds. THERM2 goes low when either RHIGH or LHIGH is set. The temperature range is set by configuring bit 2 of the Configuration Register. Setting this bit low configures the TMP411 for the standard measurement range (0°C to +127°C); temperature conversions will be stored in the standard binary format. Setting bit 2 high configures the TMP411 for the extended measurement range (−55°C to +150°C); temperature conversions will be stored in the extended binary format (see Table 1). The remaining bits of the Configuration Register are reserved and must always be set to ‘0’. The power-on reset value for this register is 00h. Table 5 summarizes the bits of the Configuration Register. Table 5. Configuration Register Bit Descriptions CONFIGURATION REGISTER (Read = 02h, Write = NA, POR = 00h) 12 BIT NAME FUNCTION POWER-ON RESET VALUE 7 MASK 0 = ALERT Enabled 1 = ALERT Masked 0 6 SD 0 = Run 1 = Shut Down 0 5 AL/TH 0 = ALERT Mode 1 = THERM Mode 0 4, 3 Reserved — 0 2 Temperature Range 0 = 0°C to +127°C 1 = −55°C to +150°C 0 1, 0 Reserved — 0 "#$$ www.ti.com SBOS383A − FEBRUARY 2007 RESOLUTION REGISTER The RES1 and RES0 bits (resolution bits 1 and 0) of the Resolution Register set the resolution of the local temperature measurement channel. Remote temperature measurement channel resolution is not affected. Changing the local channel resolution also affects the conversion time and rate of the TMP411. The Resolution Register is set by writing to pointer address 1Ah and is read by reading from pointer address 1Ah. Table 6 shows the resolution bits for the Resolution Register. Table 6. Resolution Register: Local Channel Programmable Resolution power dissipation to be balanced with the temperature register update rate. Table 7 shows the conversion rate options and corresponding current consumption. N-FACTOR CORRECTION REGISTER The TMP411 allows for a different n-factor value to be used for converting remote channel measurements to temperature. The remote channel uses sequential current excitation to extract a differential VBE voltage measurement to determine the temperature of the remote transistor. Equation 1 relates this voltage and temperature. ǒII Ǔ V BE2 * V BE1 + nkT q ln RESOLUTION REGISTER (Read = 1Ah, Write = 1Ah, POR = 1Ch) RES1 RES0 RESOLUTION CONVERSION TIME (Typical) 0 0 9 Bits (0.5°C) 12.5ms 0 1 10 Bits (0.25°C) 25ms 1 0 11 Bits (0.125°C) 50ms 1 1 12 Bits (0.0625°C) 100ms The Conversion Rate Register controls the rate at which temperature conversions are performed. This register adjusts the idle time between conversions but not the conversion timing itself, thereby allowing the TMP411 (1) 1 The value n in Equation 1 is a characteristic of the particular transistor used for the remote channel. The default value for the TMP411 is n = 1.008. The value in the N-Factor Correction Register may be used to adjust the effective n-factor according to Equation 2 and Equation 3. n eff + 1.008 @ 300 ǒ300*NADJUSTǓ Bits 2 through 4 of the Resolution Register must always be set to ‘1’. Bits 5 through 7 of the Resolution Register must always be set to ‘0’. The power-on reset value of this register is 1Ch. CONVERSION RATE REGISTER 2 ǒ (2) Ǔ 1.008 N ADJUST + 300* 300 @ neff (3) The n-correction value must be stored in two’s-complement format, yielding an effective data range from −128 to +127. The n-correction value may be written to and read from pointer address 18h. The register power-on reset value is 00h, thus having no effect unless written to. Table 7. Conversion Rate Register CONVERSION RATE REGISTER (Read = 04h, Write = 04h, POR = 08h) AVERAGE IQ (TYP) (µA) R7 R6 R5 R4 R3 R2 R1 R0 CONVERSION/SEC VS = 2.7V VS = 5.5V 0 0 0 0 0 0 0 0 0.0625 11 32 0 0 0 0 0 0 0 1 0.125 17 38 0 0 0 0 0 0 1 0 0.25 28 49 0 0 0 0 0 0 1 1 0.5 47 69 0 0 0 0 0 1 0 0 1 80 103 0 0 0 0 0 1 0 1 2 128 155 0 0 0 0 0 1 1 0 4 190 220 8 373 413 07h to 0Fh 13 "#$$ www.ti.com SBOS383A − FEBRUARY 2007 Table 8. N-Factor Range power-on by executing the chip reset command, or by writing any value to any of pointer addresses 30h through 37h. The reset value for these registers is FFh/F0h. NADJUST BINARY HEX DECIMAL N 01111111 7F 127 1.747977 00001010 0A 10 1.042759 00001000 08 8 1.035616 00000110 06 6 1.028571 00000100 04 4 1.021622 00000010 02 2 1.014765 00000001 01 1 1.011371 00000000 00 0 1.008 11111111 FF −1 1.004651 11111110 FE −2 1.001325 11111100 FC −4 0.994737 11111010 FA −6 0.988235 11111000 F8 −8 0.981818 11110110 F6 −10 0.975484 10000000 80 −128 0.706542 MINIMUM AND MAXIMUM REGISTERS The TMP411 stores the minimum and maximum temperature measured since power-on, chip-reset, or minimum and maximum register reset for both the local and remote channels. The Local Temperature Minimum Register may be read by reading the high byte from pointer address 30h and the low byte from pointer address 31h. The Local Temperature Minimum Register may also be read by using a two-byte read command from pointer address 30h. The Local Temperature Minimum Register is reset at power-on, by executing the chip-reset command, or by writing any value to any of pointer addresses 30h through 37h. The reset value for these registers is FFh/F0h. The Local Temperature Maximum Register may be read by reading the high byte from pointer address 32h and the low byte from pointer address 33h. The Local Temperature Maximum Register may also be read by using a two-byte read command from pointer address 32h. The Local Temperature Maximum Register is reset at power-on by executing the chip reset command, or by writing any value to any of pointer addresses 30h through 37h. The reset value for these registers is 00h/00h. The Remote Temperature Minimum Register may be read by reading the high byte from pointer address 34h and the low byte from pointer address 35h. The Remote Temperature Minimum Register may also be read by using a two-byte read command from pointer address 34h. The Remote Temperature Minimum Register is reset at 14 The Remote Temperature Maximum Register may be read by reading the high byte from pointer address 36h and the low byte from pointer address 37h. The Remote Temperature Maximum Register may also be read by using a two-byte read command from pointer address 36h. The Remote Temperature Maximum Register is reset at power-on by executing the chip reset command, or by writing any value to any of pointer addresses 30h through 37h. The reset value for these registers is 00h/00h. SOFTWARE RESET The TMP411 may be reset by writing any value to Pointer Register FCh. This restores the power-on reset state to all of the TMP411 registers as well as abort any conversion in process and clear the ALERT and THERM pins. The TMP411 also supports reset via the two-wire general call address (00000000). The TMP411 acknowledges the general call address and responds to the second byte. If the second byte is 00000110, the TMP411 executes a software reset. The TMP411 takes no action in response to other values in the second byte. CONSECUTIVE ALERT REGISTER The value in the Consecutive Alert Register (address 22h) determines how many consecutive out-of-limit measurements must occur on a measurement channel before the ALERT signal is activated. The value in this register does not affect bits in the Status Register. Values of one, two, three, or four consecutive conversions can be selected; one conversion is the default. This function allows additional filtering for the ALERT pin. The consecutive alert bits are shown in Table 9. Table 9. Consecutive Alert Register CONSECUTIVE ALERT REGISTER (READ = 22h, WRITE = 22h, POR = 80h) C2 C1 C0 NUMBER OF CONSECUTIVE OUT-OF-LIMIT MEASUREMENTS 0 0 0 1 0 0 1 2 0 1 1 3 1 1 1 4 NOTE: Bit 7 of the Consecutive Alert Register controls the enable/disable of the timeout function. See the Timeout Function section for a description of this feature. "#$$ www.ti.com SBOS383A − FEBRUARY 2007 THERM HYSTERESIS REGISTER To address a specific device, a START condition is initiated. START is indicated by pulling the data line (SDA) from a high to low logic level while SCL is high. All slaves on the bus shift in the slave address byte, with the last bit indicating whether a read or write operation is intended. During the ninth clock pulse, the slave being addressed responds to the master by generating an Acknowledge and pulling SDA low. The THERM Hysteresis Register stores the hysteresis value used for the THERM pin alarm function. This register must be programmed with a value that is less than the Local Temperature High Limit Register value, Remote Temperature High Limit Register value, Local THERM Limit Register value, or Remote THERM Limit Register value; otherwise, the respective temperature comparator will not trip on the measured temperature falling edges. Allowable hysteresis values are shown in Table 10. The default hysteresis value is 10°C, whether the device is operating in the standard or extended mode setting. Data transfer is then initiated and sent over eight clock pulses followed by an Acknowledge bit. During data transfer SDA must remain stable while SCL is high, because any change in SDA while SCL is high is interpreted as a control signal. Once all data has been transferred, the master generates a STOP condition. STOP is indicated by pulling SDA from low to high, while SCL is high. Table 10. Allowable THERM Hysteresis Values THERM HYSTERESIS VALUE TEMPERATURE (°C) TH[11:4] (STANDARD BINARY) (HEX) 0 0000 0000 00 1 0000 0001 01 5 0000 0101 05 10 0000 1010 0A 25 0001 1001 19 50 0011 0010 32 4B SERIAL INTERFACE The TMP411 operates only as a slave device on either the Two-Wire bus or the SMBus. Connections to either bus are made via the open-drain I/O lines, SDA and SCL. The SDA and SCL pins feature integrated spike suppression filters and Schmitt triggers to minimize the effects of input spikes and bus noise. The TMP411 supports the transmission protocol for fast (1kHz to 400kHz) and high-speed (1kHz to 3.4MHz) modes. All data bytes are transmitted MSB first. 75 0100 1011 100 0110 0100 64 125 0111 1101 7D 127 0111 1111 7F 150 1001 0110 96 SERIAL BUS ADDRESS 175 1010 1111 AF 200 1100 1000 C8 225 1110 0001 E1 255 1111 1111 FF To communicate with the TMP411, the master must first address slave devices via a slave address byte. The slave address byte consists of seven address bits, and a direction bit indicating the intent of executing a read or write operation. The address of the TMP411 is 4Ch (1001100b). BUS OVERVIEW READ/WRITE OPERATIONS The TMP411 is SMBus interface-compatible. In SMBus protocol, the device that initiates the transfer is called a master, and the devices controlled by the master are slaves. The bus must be controlled by a master device that generates the serial clock (SCL), controls the bus access, and generates the START and STOP conditions. Accessing a particular register on the TMP411 is accomplished by writing the appropriate value to the Pointer Register. The value for the Pointer Register is the first byte transferred after the slave address byte with the R/W bit low. Every write operation to the TMP411 requires a value for the Pointer Register (see Figure 14). Table 11. THERM Hysteresis Register Format THERM HYSTERESIS REGISTER (Read = 21h, Write = 21h, POR = 0Ah) BIT # BIT NAME POR VALUE D7 D6 D5 D4 D3 D2 D1 D0 TH11 TH10 TH9 TH8 TH7 TH6 TH5 TH4 0 0 0 0 1 0 1 0 15 "#$$ www.ti.com SBOS383A − FEBRUARY 2007 When reading from the TMP411, the last value stored in the Pointer Register by a write operation is used to determine which register is read by a read operation. To change the register pointer for a read operation, a new value must be written to the Pointer Register. This transaction is accomplished by issuing a slave address byte with the R/W bit low, followed by the Pointer Register byte. No additional data is required. The master can then generate a START condition and send the slave address byte with the R/W bit high to initiate the read command. See Figure 15 for details of this sequence. If repeated reads from the same register are desired, it is not necessary to continually send the Pointer Register bytes, because the TMP411 retains the Pointer Register value until it is changed by the next write operation. Note that register bytes are sent MSB first, followed by the LSB. TIMING DIAGRAMS The TMP411 is Two-Wire and SMBus-compatible. Figure 13 to Figure 16 describe the various operations on the TMP411. Bus definitions are given below. Parameters for Figure 13 are defined in Table 12. Bus Idle: Both SDA and SCL lines remain high. t(LOW) Start Data Transfer: A change in the state of the SDA line, from high to low, while the SCL line is high, defines a START condition. Each data transfer is initiated with a START condition. Stop Data Transfer: A change in the state of the SDA line from low to high while the SCL line is high defines a STOP condition. Each data transfer terminates with a repeated START or STOP condition. Data Transfer: The number of data bytes transferred between a START and a STOP condition is not limited and is determined by the master device. The receiver acknowledges the transfer of data. Acknowledge: Each receiving device, when addressed, is obliged to generate an Acknowledge bit. A device that acknowledges must pull down the SDA line during the Acknowledge clock pulse in such a way that the SDA line is stable low during the high period of the Acknowledge clock pulse. Setup and hold times must be taken into account. On a master receive, data transfer termination can be signaled by the master generating a Not-Acknowledge on the last byte that has been transmitted by the slave. tF tR t(HDSTA) SCL t(HDSTA) t (HIGH) t(HDDAT) t(SUSTO) t(SUSTA) t(SUDAT) SDA t(B U F) P S S Figure 13. Two-Wire Timing Diagram 16 P "#$$ www.ti.com SBOS383A − FEBRUARY 2007 Table 12. Timing Diagram Definitions for Figure 13 PARAMETER MIN MAX MIN MAX UNITS 0.4 0.001 3.4 MHz SCL Operating Frequency f(SCL) 0.001 Bus Free Time Between STOP and START Condition t(BUF) 600 160 ns Hold time after repeated START condition. After this period, the first clock is generated. t(HDSTA) 100 100 ns Repeated START Condition Setup Time t(SUSTA) 100 100 ns STOP Condition Setup Time t(SUSTO) 100 100 ns Data Hold Time t(HDDAT) 0 0 ns Data Setup Time t(SUDAT) 100 10 ns SCL Clock LOW Period t(LOW) 1300 160 ns SCL Clock HIGH Period t(HIGH) 600 60 ns Clock/Data Fall Time tF 300 160 Clock/Data Rise Time for SCL ≤ 100kHz tR tR 300 1000 160 1 9 1 ns ns 9 … SCL 1 SDA 0 0 1 1 0 0(1) Start By Master R/W P7 P6 P5 P4 P3 P2 P1 ACK By TMP411A ACK By TMP411A Frame 2 Pointer Register Byte Frame 1 Two−Wire Slave Address Byte 1 … P0 9 1 9 SCL (Continued) SDA (Continued) D7 D6 D5 D4 D3 D2 D1 D0 D7 D6 D5 D4 D3 D2 D1 ACK By TMP411A Frame 3 Data Byte 1 D0 ACK By TMP411A Stop By Master Frame 4 Data Byte 2 NOTE (1): Bit = 0 for TMP411A. Bit = 1 for TMP411B. Figure 14. Two-Wire Timing Diagram for Write Word Format 17 "#$$ www.ti.com SBOS383A − FEBRUARY 2007 1 9 1 9 … SCL SDA 1 0 0 1 1 0(1) 0 R/W Start By Master P7 P6 P5 P4 P3 P2 P1 … P0 ACK By TMP411A ACK By TMP411A Frame 1 Two−Wire Slave Address Byte Frame 2 Pointer Register Byte 1 9 1 9 … SCL (Continued) SDA (Continued) 1 0 0 1 1 0(1) 0 R/W Start By Master D7 D6 D5 D4 D3 D2 ACK By TMP411A … D0 From TMP411A Frame 3 Two−Wire Slave Address Byte 1 D1 ACK By Master Frame 4 Data Byte 1 Read Register 9 SCL (Continued) SDA (Continued) D7 D6 D5 D4 D3 D2 D1 D0 From TMP411 ACK By Master Stop By Master Frame 5 Data Byte 2 Read Register NOTE (1): Bit = 0 for TMP411A. Bit = 1 for TMP411B. Figure 15. Two-Wire Timing Diagram for Read Word Format ALERT 1 9 1 9 SCL SDA 0 0 0 1 1 0 Start By Master 0 R/W 1 0 0 1 1 ACK By TMP411A Frame 1 SMBus ALERT Response Address Byte 0(1) From TMP411A Frame 2 Slave Address Byte NOTE (1): Bit = 0 for TMP411A. Bit = 1 for TMP411B. Figure 16. Timing Diagram for SMBus ALERT 18 0 Status NACK By Master Stop By Master "#$$ www.ti.com SBOS383A − FEBRUARY 2007 HIGH-SPEED MODE In order for the Two-Wire bus to operate at frequencies above 400kHz, the master device must issue a High-speed mode (Hs-mode) master code (00001XXX) as the first byte after a START condition to switch the bus to high-speed operation. The TMP411 will not acknowledge this byte, but will switch the input filters on SDA and SCL and the output filter on SDA to operate in Hs-mode, allowing transfers at up to 3.4MHz. After the Hs-mode master code has been issued, the master transmits a Two-Wire slave address to initiate a data transfer operation. The bus continues to operate in Hs-mode until a STOP condition occurs on the bus. Upon receiving the STOP condition, the TMP411 switches the input and output filter back to fast-mode operation. TIMEOUT FUNCTION When bit 7 of the Consecutive Alert Register is set high, the TMP411 timeout function is enabled. The TMP411 resets the serial interface if either SCL or SDA are held low for 30ms (typical) between a START and STOP condition. If the TMP411 is holding the bus low, it releases the bus and waits for a START condition. To avoid activating the timeout function, it is necessary to maintain a communication speed of at least 1kHz for the SCL operating frequency. The default state of the timeout function is enabled (bit 7 = high). THERM (PIN 4) AND ALERT/THERM2 (PIN 6) The TMP411 has two pins dedicated to alarm functions, the THERM and ALERT/THERM2 pins. Both pins are open-drain outputs that each require a pull-up resistor to V+. These pins can be wire-ORed together with other alarm pins for system monitoring of multiple sensors. The THERM pin provides a thermal interrupt that cannot be software disabled. The ALERT pin is intended for use as an earlier warning interrupt, and can be software disabled, or masked. The ALERT/THERM2 pin can also be configured for use as THERM2, a second THERM pin (Configuration Register: AL/TH bit = 1). The default setting configures pin 6 to function as ALERT (AL/TH = 0). The THERM pin asserts low when either the measured local or remote temperature is outside of the temperature range programmed in the corresponding Local/Remote THERM Limit Register. The THERM temperature limit range can be programmed with a wider range than that of the limit registers, which allows ALERT to provide an earlier warning than THERM. The THERM alarm resets automatically when the measured temperature returns to within the THERM temperature limit range minus the hysteresis value stored in the THERM Hysteresis Register. The allowable values of hysteresis are shown in Table 10. The default hysteresis is 10°C. When the ALERT/THERM2 pin is configured as a second thermal alarm (Configuration Register: bit 7 = 0, bit 5 = 1), it functions the same as THERM, but uses the temperatures stored in the Local/Remote Temperature High/Low Limit Registers to set its comparison range. When ALERT/THERM2 (pin 6) is configured as ALERT (Configuration Register: bit 7 = 0, bit 5 = 0), the pin asserts low when either the measured local or remote temperature violates the range limit set by the corresponding Local/Remote Temperature High/Low Limit Registers. This alert function can be configured to assert only if the range is violated a specified number of consecutive times (1, 2, 3, or 4). The consecutive violation limit is set in the Consecutive Alert Register. False alerts that occur as a result of environmental noise can be prevented by requiring consecutive faults. ALERT also asserts low if the remote temperature sensor is open-circuit. When the MASK function is enabled (Configuration Register: bit 7 = 1), ALERT is disabled (that is, masked). ALERT resets when the master reads the device address, as long as the condition that caused the alert no longer persists, and the Status Register has been reset. THERM Limit and ALERT High Limit Measured Temperature ALERT Low Limit and THERM Limit Hysteresis THERM ALERT SMBus ALERT Read Read Read Time Figure 17. SMBus Alert Timing Diagram 19 "#$$ www.ti.com SBOS383A − FEBRUARY 2007 SMBUS ALERT FUNCTION UNDER-VOLTAGE LOCKOUT The TMP411 supports the SMBus Alert function. When pin 6 is configured as an alert output, the ALERT pin of the TMP411 may be connected as an SMBus Alert signal. When a master detects an alert condition on the ALERT line, the master sends an SMBus Alert command (00011001) on the bus. If the ALERT pin of the TMP411 is active, the devices will acknowledge the SMBus Alert command and respond by returning its slave address on the SDA line. The eighth bit (LSB) of the slave address byte indicates whether the temperature exceeding one of the temperature high limit settings or falling below one of the temperature low limit settings caused the alert condition. This bit will be high if the temperature is greater than or equal to one of the temperature high limit settings; this bit will be low if the temperature is less than one of the temperature low limit settings. See Figure 16 for details of this sequence. The TMP411 senses when the power-supply voltage has reached a minimum voltage level for the ADC converter to function. The detection circuitry consists of a voltage comparator that enables the ADC converter after the power supply (V+) exceeds 2.45V (typical). The comparator output is continuously checked during a conversion. The TMP411 will not perform a temperature conversion if the power supply is not valid. The last valid measured temperature is used for the temperature measurement result. If multiple devices on the bus respond to the SMBus Alert command, arbitration during the slave address portion of the SMBus Alert command determines which device will clear its alert status. If the TMP411 wins the arbitration, its ALERT pin becomes inactive at the completion of the SMBus Alert command. If the TMP411 loses the arbitration, the ALERT pin remains active. GENERAL CALL RESET The TMP411 supports reset via the Two-Wire General Call address 00h (0000 0000b). The TMP411 acknowledges the General Call address and responds to the second byte. If the second byte is 06h (0000 0110b), the TMP411 executes a software reset. This software reset restores the power-on reset state to all TMP411 registers, aborts any conversion in progress, and clears the ALERT and THERM pins. The TMP411 takes no action in response to other values in the second byte. IDENTIFICATION REGISTERS SHUTDOWN MODE (SD) The TMP411 Shutdown Mode allows the user to save maximum power by shutting down all device circuitry other than the serial interface, reducing current consumption to typically less than 3µA; see typical characteristic curve Shutdown Quiescent Current vs Supply Voltage. Shutdown Mode is enabled when the SD bit of the Configuration Register is high; the device shuts down once the current conversion is completed. When SD is low, the device maintains a continuous conversion state. The TMP411 allows for the Two-Wire bus controller to query the device for manufacturer and device IDs to allow for software identification of the device at the particular Two-Wire bus address. The manufacturer ID is obtained by reading from pointer address FEh. The device ID is obtained by reading from pointer address FFh. The TMP411 returns 55h for the manufacturer code and 11h for the device ID. These registers are read-only. FILTERING SENSOR FAULT The TMP411 will sense a fault at the D+ input resulting from incorrect diode connection or an open circuit. The detection circuitry consists of a voltage comparator that trips when the voltage at D+ exceeds (V+) − 0.6V (typical). The comparator output is continuously checked during a conversion. If a fault is detected, the last valid measured temperature is used for the temperature measurement result, the OPEN bit (Status Register, bit 2) is set high, and, if the alert function is enabled, ALERT asserts low. When not using the remote sensor with the TMP411, the D+ and D− inputs must be connected together to prevent meaningless fault warnings. 20 Remote junction temperature sensors are usually implemented in a noisy environment. Noise is most often created by fast digital signals, and it can corrupt measurements. The TMP411 has a built-in 65kHz filter on the inputs of D+ and D− to minimize the effects of noise. However, a bypass capacitor placed differentially across the inputs of the remote temperature sensor is recommended to make the application more robust against unwanted coupled signals. The value of the capacitor should be between 100pF and 1nF. Some applications attain better overall accuracy with additional series resistance; however, this increased accuracy is setup-specific. When series resistance is added, the value should not be greater than 3kΩ. "#$$ www.ti.com SBOS383A − FEBRUARY 2007 REMOTE SENSING The TMP411 is designed to be used with either discrete transistors or substrate transistors built into processor chips and ASICs. Either NPN or PNP transistors can be used, as long as the base-emitter junction is used as the remote temperature sense. Either a transistor or diode connection can also be used; see Figure 11. Errors in remote temperature sensor readings will be the consequence of the ideality factor and current excitation used by the TMP411 versus the manufacturer-specified operating current for a given transistor. Some manufacturers specify a high-level and low-level current for the temperature-sensing substrate transistors. The TMP411 uses 6µA for ILOW and 120µA for IHIGH. The TMP411 allows for different n-factor values; see the N-Factor Correction Register section. The ideality factor (n) is a measured characteristic of a remote temperature sensor diode as compared to an ideal diode. The ideality factor for the TMP411 is trimmed to be 1.008. For transistors whose ideality factor does not match the TMP411, Equation 4 can be used to calculate the temperature error. Note that for the equation to be used correctly, actual temperature (°C) must be converted to Kelvin (°K). ǒ Ǔ T ERR + n * 1.008 1.008 ǒ273.15 ) Tǒ °CǓǓ (4) Where: n = Ideality factor of remote temperature sensor T(°C) = actual temperature TERR = Error in TMP411 reading due to n ≠ 1.008 Degree delta is the same for °C and °K For n = 1.004 and T(°C) = 100°C: ǒ Ǔ T ERR + 1.004 * 1.008 1.008 T ERR + * 1.48°C ǒ273.15 ) 100°CǓ (5) If a discrete transistor is used as the remote temperature sensor with the TMP411, the best accuracy can be achieved by selecting the transistor according to the following criteria: 1. Base-emitter voltage > 0.25V at 6µA, at the highest sensed temperature. 2. Base-emitter voltage < 0.95V at 120µA, at the lowest sensed temperature. 3. Base resistance < 100Ω. 4. Tight control of VBE characteristics indicated by small variations in hFE (that is, 50 to 150). Based on these criteria, two recommended small-signal transistors are the 2N3904 (NPN) or 2N3906 (PNP). MEASUREMENT ACCURACY AND THERMAL CONSIDERATIONS The temperature measurement accuracy of the TMP411 depends on the remote and/or local temperature sensor being at the same temperature as the system point being monitored. Clearly, if the temperature sensor is not in good thermal contact with the part of the system being monitored, then there will be a delay in the response of the sensor to a temperature change in the system. For remote temperature sensing applications using a substrate transistor (or a small, SOT23 transistor) placed close to the device being monitored, this delay is usually not a concern. The local temperature sensor inside the TMP411 monitors the ambient air around the device. The thermal time constant for the TMP411 is approximately two seconds. This constant implies that if the ambient air changes quickly by 100°C, it would take the TMP411 about 10 seconds (that is, five thermal time constants) to settle to within 1°C of the final value. In most applications, the TMP411 package is in electrical and therefore thermal contact with the printed circuit board (PCB), as well as subjected to forced airflow. The accuracy of the measured temperature directly depends on how accurately the PCB and forced airflow temperatures represent the temperature that the TMP411 is measuring. Additionally, the internal power dissipation of the TMP411 can cause the temperature to rise above the ambient or PCB temperature. The internal power dissipated as a result of exciting the remote temperature sensor is negligible because of the small currents used. For a 5.5V supply and maximum conversion rate of eight conversions per second, the TMP411 dissipates 1.82mW (PDIQ = 5.5V × 330µA). If both the ALERT/THERM2 and THERM pins are each sinking 1mA, an additional power of 0.8mW is dissipated (PDOUT = 1mA × 0.4V + 1mA × 0.4V = 0.8mW). Total power dissipation is then 2.62mW (PDIQ + PDOUT) and, with an qJA of 150°C/W, causes the junction temperature to rise approximately 0.393°C above the ambient. 21 "#$$ www.ti.com SBOS383A − FEBRUARY 2007 LAYOUT CONSIDERATIONS Remote temperature sensing on the TMP411 measures very small voltages using very low currents; therefore, noise at the IC inputs must be minimized. Most applications using the TMP411 will have high digital content, with several clocks and logic level transitions creating a noisy environment. Layout should adhere to the following guidelines: 1. 2. 3. 4. 5. Place the TMP411 as close to the remote junction sensor as possible. Route the D+ and D− traces next to each other and shield them from adjacent signals through the use of ground guard traces, as shown in Figure 18. If a multilayer PCB is used, bury these traces between ground or VDD planes to shield them from extrinsic noise sources. 5 mil PCB traces are recommended. Minimize additional thermocouple junctions caused by copper-to-solder connections. If these junctions are used, make the same number and approximate locations of copper-to-solder connections in both the D+ and D− connections to cancel any thermocouple effects. Use a 0.1µF local bypass capacitor directly between the V+ and GND of the TMP411, as shown in Figure 19. Minimize filter capacitance between D+ and D− to 1000pF or less for optimum measurement performance. This capacitance includes any cable capacitance between the remote temperature sensor and TMP411. If the connection between the remote temperature sensor and the TMP411 is between 8 inches and 12 feet long, use a twisted-wire pair connection. Beyond this distance (up to 100 feet), use a twisted, shielded pair with the shield grounded as close to the TMP411 as possible. Leave the remote sensor connection end of the shield wire open to avoid ground loops and 60Hz pickup. GND(1) D+(1) Ground or V+ layer on bottom and/or top, if possible. D− (1) GND(1) NOTE: (1) 5 mil traces with 5 mil spacing. Figure 18. Example Signal Traces 0.1µF Capacitor V+ PCB Via GND 1 8 2 7 3 6 4 5 PCB Via TMP411 Figure 19. Suggested Bypass Capacitor Placement 22 PACKAGE OPTION ADDENDUM www.ti.com 19-Feb-2007 PACKAGING INFORMATION Orderable Device Status (1) Package Type Package Drawing Pins Package Eco Plan (2) Qty TMP411ADGKR ACTIVE MSOP DGK 8 2500 Green (RoHS & no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR TMP411ADGKRG4 ACTIVE MSOP DGK 8 2500 Green (RoHS & no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR TMP411ADGKT ACTIVE MSOP DGK 8 250 Green (RoHS & no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR TMP411ADGKTG4 ACTIVE MSOP DGK 8 250 Green (RoHS & no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR TMP411BDGKR ACTIVE MSOP DGK 8 2500 Green (RoHS & no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR TMP411BDGKRG4 ACTIVE MSOP DGK 8 2500 Green (RoHS & no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR TMP411BDGKT ACTIVE MSOP DGK 8 250 Green (RoHS & no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR TMP411BDGKTG4 ACTIVE MSOP DGK 8 250 Green (RoHS & no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR Lead/Ball Finish MSL Peak Temp (3) (1) The marketing status values are defined as follows: ACTIVE: Product device recommended for new designs. LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect. NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design. PREVIEW: Device has been announced but is not in production. Samples may or may not be available. OBSOLETE: TI has discontinued the production of the device. (2) Eco Plan - The planned eco-friendly classification: Pb-Free (RoHS), Pb-Free (RoHS Exempt), or Green (RoHS & no Sb/Br) - please check http://www.ti.com/productcontent for the latest availability information and additional product content details. TBD: The Pb-Free/Green conversion plan has not been defined. Pb-Free (RoHS): TI's terms "Lead-Free" or "Pb-Free" mean semiconductor products that are compatible with the current RoHS requirements for all 6 substances, including the requirement that lead not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, TI Pb-Free products are suitable for use in specified lead-free processes. Pb-Free (RoHS Exempt): This component has a RoHS exemption for either 1) lead-based flip-chip solder bumps used between the die and package, or 2) lead-based die adhesive used between the die and leadframe. The component is otherwise considered Pb-Free (RoHS compatible) as defined above. Green (RoHS & no Sb/Br): TI defines "Green" to mean Pb-Free (RoHS compatible), and free of Bromine (Br) and Antimony (Sb) based flame retardants (Br or Sb do not exceed 0.1% by weight in homogeneous material) (3) MSL, Peak Temp. -- The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder temperature. Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is provided. 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