INTEGRATED CIRCUITS NE1617A Temperature monitor for microprocessor systems Product specification Supersedes data of 2000 Jul 13 File under Integrated Circuits, IC11 Handbook 2001 Dec 14 Philips Semiconductors Product data Temperature monitor for microprocessor systems FEATURES NE1617A PIN CONFIGURATION • Replacement for Maxim MAX1617 and Analog Devices ADM1021 • Monitors local and remote temperature • Accuracy TEST 1 16 TEST VDD 2 15 STBY – ± 2 °C local (on-chip) sensor D+ 3 14 SCLK – ± 3 °C remote sensor D– 4 13 TEST TEST 5 12 SDATA ADD1 6 11 ALERT GND 7 10 ADD0 GND 8 9 • No calibration required • Programmable over/under temperature alarm • SMBus 2-wire serial interface • 3 V to 5.5 V supply range • 70 µA supply current in operating mode • 3 µA (typical) supply current in standby mode • Small 16-lead QSOP package TEST SL01202 Figure 1. Pin configuration. PIN DESCRIPTION APPLICATIONS • Desktop computers • Notebook computers • Smart battery packs • Industrial controllers • Telecom equipment DESCRIPTION The NE1617A is an accurate two-channel temperature monitor. It measures the temperature of itself and the temperature of a remote sensor. The remote sensor is a diode connected transistor. This can be in the form of either a discrete NPN/PNP, such as the 2N3904/2N3906, or a diode connected PNP built into another die, such as is done on some INTEL microprocessors. The temperature of both the remote and local sensors is stored in a register that can be read via a 2-wire SMBus. The temperatures are updated at a rate that is programmable via the SMBus (the average supply current is dependent upon the update rate—the faster the rate, the higher the current). In addition to the normal operation, which is to update the temperature at the programmed rate, there is a one shot mode that will force a temperature update. PIN # FUNCTION 1 TEST DESCRIPTION/COMMENTS 2 VDD Positive supply2 3 D+ Positive side of remote sensor 4 D– Negative side of remote sensor 5 TEST Factory use only1 6 ADD1 Device address pin (3-State) 7 GND Ground 8 GND Ground 9 TEST Factory use only1 10 ADD0 Device address pin (3-State) 11 ALERT Open drain output used as interrupt or SMBus alert 12 SDATA SMBus serial data input/output open drain 13 TEST Factory use only1 14 SCLK SMBus clock input 15 STBY Hardware standby input pin HIGH = normal operating mode LOW = standby mode 16 TEST Factory use only1 Factory use only1 NOTES: 1. These pins should either float or be tied to ground. 2. VDD pin should be decoupled by a 0.1 µF capacitor. There is also an alarm that senses either an over or under temperature condition. The trip points for this alarm are also programmable. The device can have 1 of 9 addresses (determined by 2 address pins), so there can be up to 9 of the NE1617A on the SMBus. It can also be put in a standby mode (in order to save power). This can be done either with software (over the SMBus) or with hardware (using the STBY pin). ORDERING INFORMATION PART NUMBER NE1617ADS PACKAGE 16-lead QSOP package1 DRAWING NUMBER SOT519–1 NOTE: 1. Also called SSOP16. 2001 Dec 14 2 853–2203 27461 Philips Semiconductors Product data Temperature monitor for microprocessor systems NE1617A FUNCTIONAL BLOCK DIAGRAM STDBY ONE-SHOT REGISTER CONFIGURATION REGISTER COMMAND POINTER REGISTER CONVERSION RATE REGISTER LOCAL TEMP HIGH THRESHOLD LOCAL TEMP HIGH LIMIT REGISTER LOCAL TEMP DATA REGISTER LOCAL LOW TEMP THRESHOLD LOCAL TEMP LOW LIMIT REGISTER REMOTE TEMP DATA REGISTER REMOTE HIGH TEMP THRESHOLD REMOTE TEMP HIGH LIMIT REGISTER ADD0 ADDRESS DECODER REMOTE LOW TEMP THRESHOLD REMOTE TEMP LOW LIMIT REGISTER ALERT INTERRUPT MASKING LOCAL TEMP SENSOR D+ D– ANALOG MUX CONTROL LOGIC A-TO-D CONVERTER ADD1 STATUS REGISTER SMBUS INTERFACE VDD GND GND TEST1 TEST5 TEST9 TEST13 TEST16 SCLK SDATA SL01210 Figure 2. Functional block diagram. 2001 Dec 14 3 Philips Semiconductors Product data Temperature monitor for microprocessor systems NE1617A TYPICAL OPERATING CIRCUIT 0.1 µF VDD 2 10 kΩ 15 10 kΩ 10 kΩ NE1617A 14 3 C1 (NOTE 2) CLOCK 12 DATA MICROCONTROLLER INTERRUPT 11 4 REMOTE SENSOR SHIELDED TWISTED PAIR (NOTE 1) 10 6 7 8 SL01248 NOTES: 1. May be required if remote diode is in a noisy environment and/or several feet from the NE1617A. 2. May be required in noisy environment. Up to 2200 pF may be used. Figure 3. Typical operating circuit. ABSOLUTE MAXIMUM RATINGS MIN. MAX. UNIT VDD to GND PARAMETER –0.3 +6 V D+, ADD0, ADD1 –0.3 VDD+0.3 V D– to GND –0.3 +0.8 V SCLK, SDATA, ALERT, STBY –0.3 +6 V –1 +50 mA ±1 mA 0 +120 °C +150 °C +150 °C Input current SDATA D– current Operating temperature range Maximum junction temperature Storage temperature range 2001 Dec 14 –65 4 Philips Semiconductors Product data Temperature monitor for microprocessor systems NE1617A ELECTRICAL CHARACTERISTICS VDD = 3.3 V; Tamb = 0 °C to +125 °C, unless otherwise noted. LIMITS PARAMETER CONDITIONS Temperature resolution Local temperature error Remote temperature error Under voltage lockout1 Power-on reset threshold MIN. TYP. Tamb = +60 °C to +100 °C < ±1 ±2 °C Tamb = 0 °C to +125 °C < ±2 ±3 °C Tremote = +60 °C to +100 °C ±3 °C Tremote = 0 °C to +125 °C ±5 °C 2.95 V 2.5 V 70 µA 180 µA 10 µA 170 ms +30 % VDD supply (Note 2) 2.7 VDD supply (falling edge) (Note 3) 1.0 Conversion rate = 2/sec Power supply current (standby) SMBus inactive Conversion time From stop bit to conversion complete, both channels Conversion rate error Percentage error in programmed rate Remote sensor source current Address pin bias current UNIT °C 1 Conversion rate = 0.25/sec Power supply current (average) MAX. 3 –30 HIGH level 100 µA LOW level 10 µA Momentary as the address is being read (Notes 4 and 5) 160 µA NOTES: 1. Definition of Under Voltage Lockout (UVL): The value of VDD below which the internal A/D converter is disabled. This is designed to be a minimum of 200 mV above the power-on reset. During the time that it is disabled, the temperature that is in the “read temperature registers” will remain at the value that it was before the A/D was disabled. This is done to eliminate the possibility of reading unexpected false temperatures due to the A/D converter not working correctly due to low voltage. In case of power-up (rising VDD), the reading that is stored in the “read temperature registers” will be the default value of 0 °C. As soon as VDD has risen to the value of UVL, the A/D will function correctly and normal temperatures will be read. 2. VDD (rising edge) voltage below which the ADC is disabled. 3. VDD (falling edge) voltage below which the logic is reset. 4. Address is read a power up and at start of conversion for all conversions except the fastest rate. 5. Due to the bias current, any pull-up/down resistors should be ≤ 2 kΩ. 2001 Dec 14 5 Philips Semiconductors Product data Temperature monitor for microprocessor systems NE1617A SMBus INTERFACE AC SPECIFICATIONS VDD = 3.0 V to 3.6 V; Tamb = 0 _C to +125 _C unless otherwise noted. These specifications are guaranteed by design and not tested in production. 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Delay from SDA stop to SDA start See Figure 4 4.7 µs tHD:STA Hold time of start condition. Delay from SDA start to first SCL H–L See Figure 4 4.0 µs tHD:DAT Hold time of data. Delay from SCL H–L to SDA edges See Figure 4 0 ns tSU:DAT Set-up time of data. Delay from SDA edges to SCL L–H See Figure 4 250 ns tSU:STA Set-up time of repeat start condition. Delay from SCL L–H to restart SDA See Figure 4 250 ns tSU:STO Set-up time of stop condition. Delay from SCL L–H to SDA stop See Figure 4 4.0 µs Fall time of SCL and SDA See Figure 4 tF tLOW tR 1.0 µs tHD:STA tF SCLK tHD:STA tHD:DAT tHIGH tSU:STO tSU:STA tSU:DAT SDATA tBUF P S S P SL01204 Figure 4. Timing measurements. NOTE: The NE1617A does not include the SMBus timeout capability (tLOW:SEXT and tLOW:MEXT). 2001 Dec 14 6 Philips Semiconductors Product data Temperature monitor for microprocessor systems NE1617A TYPICAL PERFORMANCE CHARACTERISTICS VIN = 100mVPP and AC coupled to D– 15 6 10 4 TEMPERATURE ERROR (deg. C) TEMPERATURE ERROR (deg. C) 20 D+ TO GND 5 0 –5 D+ TO VDD –10 2 0 –2 –4 –15 –6 –20 1 10 1 100 10 100 1000 10000 FREQUENCY (kHz) LEAKAGE RESISTANCE (MΩ) SL01212 SL01214 Figure 5. Temperature error vs. PC board resistance Figure 6. Temperature error vs. common_mode noise frequency VIN = 100mVPP and AC coupled to D– and D+ 5 TEMPERATURE ERROR (deg. C) TEMPERATURE ERROR (deg. C) 6 4 2 0 –2 0 –5 –10 –15 –4 –20 –6 1 10 100 1000 0 10000 FREQUENCY (kHz) 40 60 80 100 D+ to D– CAPACITANCE (nF) SL01211 SL01213 Figure 7. Temperature error vs. differential mode noise frequency 2001 Dec 14 20 Figure 8. Temperature error vs. D+to D– capacitance 7 Philips Semiconductors Product data Temperature monitor for microprocessor systems 100 NE1617A 150 90 80 SUPPLY CURRENT (uA) 130 SUPPLY CURRENT (uA) 70 60 50 40 30 110 90 70 20 10 50 0.0625 0 1 10 100 SL01217 TEMPERATURE (deg. C) 100 75 50 25 0 4 6 8 10 TIME (SEC) SL01215 Figure 11. Response to thermal shock immersed in +115 °C fluorinert bath 2001 Dec 14 8.0 Figure 10. Operating supply current vs. conversion rate @ VCC = 3.3 V 125 2 4.0 2.0 SL01216 Figure 9. Standby supply current vs. clock frequency @ VCC = 3.3 V 0 1.0 0.5 CONVERSION RATE (Hz) SMB CLK FREQUENCY (kHz) –2 0.25 0.125 1000 8 Philips Semiconductors Product data Temperature monitor for microprocessor systems The NE1617A provides two current sources of about 10 µA and 100 µA in measuring the remote diode VBE and the sensed voltage between two pins D+ and D– is limited between 0.25 V and 0.95 V. The external diode must be selected to meet this voltage range at these two current levels. The diode-connected PNP transistor provided on the microprocessor is typically used, or the discrete diode-connected transistor 2N3904 is recommended as an alternative. FUNCTIONAL DESCRIPTION The NE1617A contains an integrating A-to-D converter, an analog multiplexer, a status register, digital data registers, SMBus interface, associated control logic and a local temperature sensor or channel. The remote diode-type sensor or channel should be connected to the D+ and D– pins properly. Temperature measurements or conversions are either automatically and periodically activated when the device is in free-running mode (both STBY pin = HIGH, and the configuration register BIT6 = LOW) or generated by one-shot command. The free-running period is selected by changing the programmable data of the conversion rate register as described later. For each conversion, the multiplexer switches current sources through the remote and local temperature sensors over a period of time, about 60 ms, and the voltages across the diode-type sensors are sensed and converted into the temperature data by the A-to-D converter. The resulting temperature data is then stored in the temperature registers, in 8-bit, two’s complement word format and automatically compared with the limits which have been programmed in the temperature limit registers. Results of the comparison are reflected accordingly by the flags stored in the status register, an out-of-limit condition will set the ALERT output pin to its LOW state. Because both channels are automatically measured for each conversion, the results are updated for both channels at the end of every successful conversion. Even though the NE1617A integrating A-to-D converter has a good noise performance, using the average of 10 measurement cycles, high frequency noise filtering between D+ and D– should be considered. An external capacitor of 2200 pF typical (but not higher than 3300 pF) connected between D+ and D– is recommended. Capacitance higher than 3300 pF will introduce measurement error due to the rise time of the switched current source. Address logic The address pins of the NE1617A can be forced into one of three levels: LOW (GND), HIGH (VDD), or Not Connected (NC). Because the NE1617A samples and latches the address pins at the starting of every conversion, it is suggested that those address pins should be hard-wired to the logic applied, so that the logic is consistently existed at the address pins. During the address sensing period, the device forces a current at each address pin and compares the voltage developed across the external connection with the predefined threshold voltage in order to define the logic level. If an external resistor is used for the connection of the address, then its value should be less than 2 kΩ to prevent the error in logic detection from happening. Resistors of 1 kΩ are recommended. Remote diode selection The method of the temperature measurement is based on the change of the diode VBE at two different operating current levels given by: DVBE + KT q < LN(N) where: K: Boltzman’s constant T: absolute temperature in ° Kelvin q: charge on the electron N: ratio of the two currents LN: natural logarithm 2001 Dec 14 NE1617A 9 Philips Semiconductors Product data Temperature monitor for microprocessor systems TEMPERATURE MONITOR WITH SMB SERIAL INTERFACE Registers The device contains more than 9 registers. They are used to store the data of device setup and operation results. Depending on the bus communication (either read or write operations), each register may be called by different names because each register may have different sub-addresses or commands for read and write operations. For example, the configuration register is called as WC for write mode and as RC for read mode. Table 2 (Register Assignments) shows the names, commands and functions of all registers as well the register POR states. Serial bus interface The device can be connected to a standard 2-wire serial interface System Management Bus (SMBus) as a slave device under the control of a master device, using two device terminals SCLK and SDATA. The operation of the device to the bus is described with details in the following sections. Slave address The device address is defined by the logical connections applied to the device pins ADD0 and ADD1. A list of selectable addresses are shown in Table 1. The device address can be set to any one of those nine combinations and more than one device can reside on the same bus without address conflict. Note that the state of the device address pins is sampled and latched not only at power-up step but also at starting point of every conversion. Note that attempting to write to a read-command or read from a write-command will produce an invalid result. The reserved registers are used for factory test purposes and should not be written to. Low power standby modes Upon POR, the device is reset to its normal free-running auto-conversion operation mode. The device can be put into standby mode by either using hardware control (connect the STBY pin to LOW for hardware standby mode) or using software control (set bit 6 of the configuration register to HIGH for software standby mode). When the device is put in either one of the standby modes, the supply current is reduced to less than 10 µA if there is no SMBus activity, all data in the device registers are retained and the SMBus interface is still alive to bus communication. However, there is a difference in the device ADC conversion operation between hardware standby and software standby modes. In hardware standby mode, the device conversion is inhibited and the one-shot command does not initiate a conversion. In software standby mode, the one-shot command will initiate a conversion for both internal and external channels. Table 1. Device slave address ADD0* ADD1* ADDRESS BYTE GND GND 0011 000 GND NC 0011 001 GND VDD 0011 010 NC GND 0101 001 NC NC 0101 010 NC VDD 0101 011 VDD GND 1001 100 VDD NC 1001 101 VDD VDD 1001 110 NE1617A If a hardware standby command is received when the device is in normal mode and a conversion is in progress, the conversion cycle will stop and data in reading temperature registers will not be updated. NC = Not Connected. * Any pull-up/down resistor used to connect to GND or VDD should be ≤ 2 kΩ. Table 2. Register assignments REGISTER NAME COMMAND BYTE POR STATE RIT 00h 0000 0000 Read internal or local temp byte RET 01h 0000 0000 Read external or remote temp byte RS 02h n/a RC 03h 0000 0000 Read configuration byte RCR 04h 0000 0010 Read conversion rate byte RIHL 05h 0111 1111 Read internal temp HIGH limit byte RILL 06h 1100 1001 Read internal temp LOW limit byte REHL 07h 0111 1111 Read external temp HIGH limit byte RELL 08h 1100 1001 Read external temp LOW limit byte WC 09h n/a Write configuration byte WCR 0Ah n/a Write conversion rate byte WIHL 0Bh n/a Write internal temp HIGH limit byte WILL 0Ch n/a Write internal temp LOW limit byte WEHL 0Dh n/a Write external temp HIGH limit byte WELL 0Eh n/a Write external temp LOW limit byte OSHT 0Fh n/a One shot command RESERVED 10h n/a Reserved RESERVED 11h n/a Reserved RESERVED 12h n/a Reserved RESERVED 13h n/a Reserved 2001 Dec 14 FUNCTION Read status byte 10 Philips Semiconductors Product data Temperature monitor for microprocessor systems NE1617A Configuration register Conversion rate register The configuration register is used to mask the Alert interrupt and/or to put the device in software standby mode. Only two bits 6 and 7 of this register are used as listed in Table 3. Bit 7 is used to mask the device ALERT output from Alert interruption when this bit is set to 1 and bit 6 is used to activate the standby software mode when this bit is set to to 1. The conversion rate register is used to store programmable conversion data, which defines the time interval between conversions in standard free-running auto-convert mode. The Table 5 shows all applicable data and rates for the device. Only three LSB bits of the register are used and other bits are reserved for future use. This register can be written to and read back over the SMBus using commands of the registers named WCR and RCR respectively. The POR default conversion data is 02h (0.25Hz). This register can be written or read using the commands of registers named WC and RC accordingly. Upon Power-On Reset (POR), both bits are reset to zero. Notice that the average supply current, as well as the device power consumption, is increased with the conversion rate. Table 3. Configuration register bit assignments BIT NAME POR STATE 7 (MSB) MASK 0 6 5 to 0 RUN/STOP RESERVED 0 n/a Table 5. Conversion rate control byte FUNCTION Mask ALERT interrupt: Interrupt is enabled when this bit is LOW, and disabled when this bit is HIGH. Standby or run mode control: When LOW, running mode is enabled. When HIGH, standby mode is initiated. n/a External and internal temperature registers Results of temperature measurements after every ADC conversion are stored in two registers: Internal Temp register (RIT) for internal or local diode temperature, and External Temp register (RET) for external or remote diode temperature. These registers can be only read over the SMBus. The reading temperature data is in 2’s complement binary form consisting of 7-bit data and 1-bit sign (MSB), with each data count represents 1 °C, and the MSB bit is transmitted first over the serial bus. The contents of those two registers are updated upon completion of each ADC conversion. Table 4 shows some values of the temperature and data. DIGITAL OUTPUT (8 BITS) +127 0 111 1111 2001 Dec 14 +126 0 111 1110 +100 0 110 0100 +50 0 011 0010 +25 0 001 1001 +1 0 000 0001 0 0 000 0000 –1 1 111 1111 –25 1 110 0111 –50 1 100 1110 –65 1 011 1111 CONVERSION RATE (Hz) AVERAGE SUPPLY CURRENT (µA Typ. @ VDD = 3.3 V) 00h 0.0625 TBD 01h 0.125 TBD 02h 0.25 TBD 03h 0.5 TBD 04h 1 TBD 05h 2 TBD 06h 4 TBD 07h 8 TBD 08h to FFh Reserved n/a Temperature limit registers The device has four registers to be used for storing programmable temperature limits, including the high limit and the low limit for each channel of the external and internal diodes. Data of the temperature register (RIT & RET) for each channel are compared with the contents of the temperature limit registers of the same channel, resulting in alarm conditions. If measured temperature either equals or exceeds the corresponding temperature limits, an Alert interrupt is asserted and the corresponding flag bit in the status register is set. The temperature limit registers can be written to and read back using commands of registers named WIHL, WILL, WEHL, WELL, RIHL, RILL, REHL, RELL accordingly. The POR default values are +127 °C (0111 1111) for the HIGH limit and –55 °C (1100 1001) for the LOW limit. Table 4. Temperature data format (2’s complement) TEMPERATURE (°C) DATA One-shot command The one shot command is not actually a data register as such and a write operation to it will initiate an ADC conversion. The send byte format of the SMBus, as described later, with the use of OSHT command (0Fh), is used for this writing operation. In normal free-running-conversion operation mode of the device, a one-shot command immediately forces a new conversion cycle to begin. However, if a conversion is in progress when a one-shot command is received, the command is ignored. In software standby mode, the one-shot command generates a single conversion and comparison cycle and then puts the device back in its standby mode after the conversion. In hardware standby mode, the one shot is inhibited. 11 Philips Semiconductors Product data Temperature monitor for microprocessor systems NE1617A Status register Alert interrupt The content of the status register reflects condition status resulting from all of these activities: comparisons between temperature measurements and temperature limits, the status of ADC conversion, and the hardware condition of the connection of external diode to the device. Bit assignments and bit functions of this register are listed in Table 6. This register can only be read using the command of register named RS. Upon POR, the status of all flag bits are reset to zero. The status byte is cleared by any successful read of the status register unless the fault condition persists. The ALERT output is used to signal Alert interruption from the device to the SMBus and is Active-LOW. Because this output is an open-drain output, a pull-up resistor (10 kΩ typ.) to VDD is required, and slave devices can share a common interrupt line on the same SMBus. An Alert interrupt is asserted by the device whenever any one of the fault conditions, as described in the Status register section, occurs: measured temperature equals or exceeds corresponding temp limits, the remote diode is physically disconnected from the device pins. Alert interrupt signal is latched and can only be cleared by reading the Alert Response byte from the Alert Response Address which is a special slave address to the SMBus. The ALERT output can not be reset by reading the device status register. The device was designed to accommodate the Alert interrupt detection capability of the SMBus.1 Notice that any one of the fault-conditions, except the conversion busy, also introduces an Alert interrupt to the SMBus that will be described in the following section. Also, whenever a one-shot command is executed, the status byte should be read after the conversion is completed, which is about 170 ms after the one-shot command is sent. Basically, the SMBus provides Alert response interrupt pointers in order to identify the slave device which has caused the Alert interrupt. The 7-bit Alert response slave address is 0001 100 and the Alert response byte reflects the slave address of the device which has caused Alert interrupt. Bit assignments of the Alert response byte are listed in Table 7. The ALERT output will be reset to HIGH state upon reading the Alert response slave address unless the fault condition persists. Table 6. Status register bit assignment * BIT NAME POR STATE 7 (MSB) BUSY n/a 6 IHLF* 0 FUNCTION High when the ADC is busy converting High when the internal temperature high limit has tripped 5 ILLF* 0 High when the internal temperature low limit has tripped 4 EHLF* 0 High when the external temperature high limit has tripped 3 ELLF* 0 Table 7. Alert response bit assignment (Alert response address = 0001 100) ALERT RESPONSE BIT NAME ADDRESS BIT FUNCTION High when the external temperature low limit has tripped 7 (MSB) ADD7 Indicate address B6 of alerted device 6 ADD6 Indicate address B5 of alerted device 5 ADD5 Indicate address B4 of alerted device 4 ADD4 Indicate address B3 of alerted device 3 ADD3 Indicate address B2 of alerted device 2 ADD2 Indicate address B1 of alerted device 1 ADD1 Indicate address B0 of alerted device 0 (LSB) 1 2 OPEN* 0 High when the external diode is opened 1 to 0 n/a 0 Reserved These flags stay high until the status register is read or POR is activated. Logic 1 1. The NE1617A implements the collision arbitration function per System Management Bus Specification Revision 1.1 dated December 11, 1998, which conforms to standard I2C arbitration as described in Philips Semiconductors document #98–8080–575–01. 2001 Dec 14 12 Philips Semiconductors Product data Temperature monitor for microprocessor systems NE1617A Power-up default condition SMBus interface Upon power-up reset (power is switched off-on), the NE1617A goes into this default condition: The device can communicate over a standard 2-wire serial interface System Management Bus (SMBus) using the device pins SCLK and SDATA. The device employs four standard SMBus protocols: Write Byte, Read Byte, Send Byte and Receive Byte. Data formats of those protocols are shown in Table 8 with following notifications: – Interrupt latch is cleared, the ALERT output is pulled HIGH by the external pull-up resistor. – The auto-conversion rate is at 0.25 Hz; conversion rate data is 02H. – Temperature limits for both channels are +127 °C for high limit, and –55 °C for low limit. – Command pointer register is set to 00 for quickly reading the RIT. – The SMBus master initiates data transfer by establishing a start condition (S) and terminates data transfer by generating a stop condition (P). – Data is sent over the serial bus in sequence of 9 clock pulses according to each 8-bit data byte followed by 1-bit status of the device acknowledgement. – The 7-bit slave address is equivalent to the selected address of the device. – The command byte is equivalent to the selected command of the device register – The send byte format is often used for the one-shot conversion command. – The receive byte format is used for quicker transfer data from a device reading register which was previously selected by a read byte format. Fault detection The NE1617A has a fault detector to the diode connection. The connection is checked when a conversion is initiated and the proper flags are set if the fault condition has occurred. D+ & D– ALERT OUTPUT RET DATA STORAGE STATUS SET FLAG Opened Low 127 °C B2 and B4 Shorted Low 127 °C B4 Table 8. SMBus programming format Write byte format (for writing data byte to the device register): S ADDRESS WR ACK COMMAND ACK DATA ACK 7 bits device address 1 bit = 0 by device 8 bits device register by device 8 bits to register by device P Read byte format (for reading data byte from the device register): S ADDRESS WR ACK COMMAND ACK 7 bits device address 1 bit = 0 by device 8 bits device register by device S ADDRESS RD ACK 7 bits device address 1 bit = 1 by device Send byte format (for sending command without data, such as one-shot command): S ADDRESS WR ACK COMMAND ACK 7 bits device address 1 bit = 0 by device 8 bits device register by device P Receive byte format (for continuously reading from device register): S ADDRESS RD ACK DATA NACK 7 bits device address 1 bit = 1 by device 8 bits from register by controller P NOTES: S = Start condition P = Stop condition ACK = Acknowledged NACK = Not acknowledged 2001 Dec 14 13 DATA 8 bits from register NACK by controller P Philips Semiconductors Product data Temperature monitor for microprocessor systems NE1617A PC BOARD LAYOUT CONSIDERATION GND Because the NE1617A is used to measure a very small voltage from the remote sensor, care must be taken to minimize noise induced at the sensor inputs, especially in the computer motherboard noisy environment. These precautions should be considered: D+ D– – Place the NE1617A as close as possible to the remote sensor. It can be from 4 to 8 inches, as long as the worst noise sources such as clock generator, data and address buses, CRTs are avoided. GND SL01218 – Route the D+ and D– lines in parallel and close together with ground guards enclosed. – Place a bypass capacitor of 0.1 µF close to the VDD pin and an input filter capacitor of 2200 pF close to the D+ and D– pins. – Leakage currents due to PC board contamination must be considered. Error can be introduced by the leakage current as shown on the characteristics curve (Temperature Error vs. PC Board Resistance, Figure 5). – A shielded twisted pair is recommended for a long distance remote sensor. Connect the shield of the cable at the device side to the NE1617A GND pin and leave the shield at the remote end unconnected to avoid ground loop. Also notice that the series resistance of the cable may introduce measurement error; 1 Ω can introduce about 0.5 °C. – Use wide tracks to reduce inductance and noise pickup that may be introduced by narrow ones. The width of 10 mil and space of 10 mil are recommended. 2001 Dec 14 14 Philips Semiconductors Product data Temperature monitor for microprocessor systems SSOP16: plastic shrink small outline package; 16 leads; body width 3.9 mm; lead pitch 0.635 mm 2001 Dec 14 15 NE1617A SOT519-1 Philips Semiconductors Product data Temperature monitor for microprocessor systems NE1617A Data sheet status Data sheet status [1] Product status [2] Definitions Objective data Development This data sheet contains data from the objective specification for product development. Philips Semiconductors reserves the right to change the specification in any manner without notice. Preliminary data Qualification This data sheet contains data from the preliminary specification. Supplementary data will be published at a later date. Philips Semiconductors reserves the right to change the specification without notice, in order to improve the design and supply the best possible product. Product data Production This data sheet contains data from the product specification. Philips Semiconductors reserves the right to make changes at any time in order to improve the design, manufacturing and supply. Changes will be communicated according to the Customer Product/Process Change Notification (CPCN) procedure SNW-SQ-650A. [1] Please consult the most recently issued data sheet before initiating or completing a design. [2] The product status of the device(s) described in this data sheet may have changed since this data sheet was published. The latest information is available on the Internet at URL http://www.semiconductors.philips.com. Definitions Short-form specification — The data in a short-form specification is extracted from a full data sheet with the same type number and title. For detailed information see the relevant data sheet or data handbook. Limiting values definition — Limiting values given are in accordance with the Absolute Maximum Rating System (IEC 60134). Stress above one or more of the limiting values may cause permanent damage to the device. These are stress ratings only and operation of the device at these or at any other conditions above those given in the Characteristics sections of the specification is not implied. Exposure to limiting values for extended periods may affect device reliability. Application information — Applications that are described herein for any of these products are for illustrative purposes only. Philips Semiconductors make no representation or warranty that such applications will be suitable for the specified use without further testing or modification. Disclaimers Life support — These products are not designed for use in life support appliances, devices or systems where malfunction of these products can reasonably be expected to result in personal injury. Philips Semiconductors customers using or selling these products for use in such applications do so at their own risk and agree to fully indemnify Philips Semiconductors for any damages resulting from such application. Right to make changes — Philips Semiconductors reserves the right to make changes, without notice, in the products, including circuits, standard cells, and/or software, described or contained herein in order to improve design and/or performance. Philips Semiconductors assumes no responsibility or liability for the use of any of these products, conveys no license or title under any patent, copyright, or mask work right to these products, and makes no representations or warranties that these products are free from patent, copyright, or mask work right infringement, unless otherwise specified. Koninklijke Philips Electronics N.V. 2002 All rights reserved. Printed in U.S.A. Contact information For additional information please visit http://www.semiconductors.philips.com. Fax: +31 40 27 24825 Date of release: 01-02 For sales offices addresses send e-mail to: [email protected]. Document order number: 2001 Dec 14 16 9397 750 09273