DS1731U

DS1631-DS1731 DALLAS | Alldatasheet

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Technical content

FEATURES

/g167 DS1631 and DS1631A Provide /g1770.5°C Accuracy over a 0°C to +70°C Range /g167 DS1731 Provides /g1771°C Accuracy over a -10°C to +85°C Range /g167 DS1631A Automatically Begins Taking Temperature Measurements at Power-Up /g167 Operating Temperature Range: -55°C to /g167 Temperature Measurements Require No External Components /g167 Output Resolution is User-Selectable to 9, 10, 11, or 12 Bits /g167 Wide Power-Supply Range (+2.7V to +5.5V) /g167 Converts Temperature-to-Digital Word in 750ms (max) /g167 Multidrop Capability Simplifies Distributed Temperature-Sensing Applications /g167 Thermostatic Settings are User-Definable and Nonvolatile (NV) /g167 Data is Read/Written Through 2-Wire Serial Interface (SDA and SCL Pins) /g167 All Three Devices are Available in 8-Pin /g109SOP Packages and the DS1631 is Also Available in a 150mil SO package—see Table 1 for Ordering Information PIN CONFIGURATIONS

DESCRIPTION

The DS1631, DS1631A, and DS1731 digital thermomete rs provide 9, 10, 11, or 12-bit temperature readings over a -55°C to +125°C range. Th e DS1631 and DS1631A thermometer accuracy is /g1770.5°C from 0°C to +70°C with 3.0V /g163 VDD /g163 5.5V, and the DS1731 accuracy is /g1771°C from -10°C to +85°C with 3.0V /g163 VDD /g163 5.5V. The thermostat on all three devices provide s custom hysteresis with user-defined trip points (T H and T L). The T H and T L registers and thermometer configuration settings are stored in NV EEPROM so they can be programmed prior to in stallation. In addition, the DS1631A automatically begins taking temperature measurements at powe r-up, which allows it to f unction as a stand-alone thermostat. Communication with the DS1631/DS1631A /DS1731 is achieved through a 2-wire serial interface, and three address pins allow up to eight devices to be multidropped on the same 2-wire bus. Pin descriptions for the DS1631/DS 1631A/DS1731 are provided in Table 2 and user-accessible registers are summarized in Table 3. A functional diagram is shown in Figure 1. DS1631/DS1631A/DS1731 High-Precision Digital Thermometer and Thermostat www.maxim-ic.com SO (150mil) (DS1631Z) SCL VDD A2GND TOUT SDA /g109SOP (DS1631U, DS1631AU, DS1731U) SCL VDD A2GND TOUT SDA See Table 2 for Pin Descriptions

APPLICATIONS

/g167 Network Routers and Switches /g167 Cellular Base Stations /g167 Portable Products /g167 Any Space-Constrained Thermally Sensitive Product

Table 1. ORDERING INFORMATION Table 2. DETAILED PIN DESCRIPTION 1 SDA Data Input/Output Pin for 2-Wire Serial Communication Port. Open-Drain. 2 SCL Clock Input Pin for 2-Wire Serial Communication Port. 3T OUT Thermostat Output Pin. Push-Pull.

4 GND Ground Pin

8V DD Supply Voltage Pin. +2.7V to +5.5V Power-Supply Pin. Figure 1. FUNCTIONAL DIAGRAM

ABSOLUTE MAXIMUM RATINGS* Voltage on any Pin Relative to Ground -0.5V to +6.0V Operating Temperature Range -55°C to +125°C Storage Temperature Range -55°C to +125°C Solder Dip Temperature (10s) See IPC/JEDEC J-STD-020A Specification Reflow Oven Temperature +220°C * These are stress ratings only and functional operation of the device at these or any other conditions above those indicated in the operation sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods of time may affect reliability. DC ELECTRICAL CHARACTERISTICS (VDD = 2.7V to 5.5V; TA = -55°C to +125°C.) PARAMETER SYMBOL CONDITION MIN MAX UNITS NOTES Supply Voltage V DD 2.7 5.5 V 1 0°C to +70°C, 3.0V /g163 VDD /g163 5.5V ±0.5 0°C to +70°C, 2.7V /g163 VDD /g60 3.0V ±1 DS1631, DS1631A Thermometer Error TERR -55°C to +125°C ±2 °C 2 -10°C to +85°C, 3.0V /g163 VDD /g163 5.5V ±1 -10°C to +85°C, 2.7V /g163 VDD /g60 3.0V ±1.5 DS1731 Thermometer Error TERR -55°C to +125°C ±2 °C 2 Low-Level Input Voltage VIL -0.5 0.3 x V DD V High-Level Input Voltage VIH 0.7 x VDD VDD + 0.3 V VOL1 3mA sink current 0 0.4SDA Low-Level Output Voltage V OL2 6mA sink current 0 0.6 V Input Current Each I/O Pin 0.4 < VI/O < 0.9VDD -10 +10 µA Temperature conversion -55°C to +85°C Temperature conversion +85°C to +125°C 1.25 mA E2 write 400 Active Supply Current IDD Communication only 110 µA Standby Supply Current ISTBY 0°C to +70°C 800 nA 4 VOH 1mA source current 2.4 V 1TOUT Output Logic Voltage VOL 4mA sink current 0.4 V 1

AC ELECTRICAL CHARACTERISTICS (VDD = 2.7V to 5.5V; TA = -55°C to +125°C.) PARAMETER SYMBOL CONDITION MIN TYP MAX UNITS NOTES 9-bit resolution 93.75 10-bit resolution 187.5 11-bit resolution 375 Temperature Conversion Time tTC 12-bit resolution 750 ms SCL Frequency f SCL 0 400 kHz Bus Free Time Between a STOP and START Condition t BUF 1.3 µs 5 START and Repeated START Hold Time from Falling SCL t HD:STA 0.6 µs 5, 6 Low Period of SCL t LOW 1.3 µs 5 High Period of SCL t HIGH 0.6 µs 5 Repeated START Condition Setup Time to Rising SCL t SU:STA 0.6 µs 5 Data-Out Hold Time from Falling SCL tHD:DAT 0 0.9 µs 5 Data-In Setup Time to Rising SCL tSU:DAT 100 ns 5 Rise Time of SDA and SCL tR 20 + 0.1CB 1000 ns 5, 7 Fall Time of SDA and SCL tF 20 + 0.1CB 300 ns 5, 7 STOP Setup Time to Rising SCL tSU:STO 0.6 µs 5 Capacitive Load for Each Bus Line CB 400 pF I/O Capacitance C I/O 10 pF Input Capacitance C I 5p F Spike Pulse Width that can be Suppressed by Input Filter t SP 05 0 n s NOTES: 1) All voltages are referenced to GND. 2) See Figure 2 for Typical Operating Curves. 3) Specified with TOUT pin open; A0, A1, A2 = 0V or VDD; and fSCL /g179 2Hz. 4) Specified with temperature conversions stopped; TOUT pin open; SDA = VDD; SCL = VDD; and A0, A1, A2 = 0V or VDD. 5) See Timing Diagram in Figure 3. All timing is referenced to 0.9 x VDD and 0.1 x VDD. 6) After this period the first clock pulse is generated. 7) For example, if CB = 300pF, then tR[min] = tF[min] = 50ns.

Table 3. REGISTER SUMMARY Power-up state: user defined. Power-up state: user defined.

1 SRAM,

6 MSbs = SRAM

2 LSbs (POL and 1SHOT bits) = EEPROM

temperature measurement and ADC sequence. state until a single temperature conversion is again initiated by a Start Convert T command. configuration register. Note that the conversion time doubles for each additional bit of resolution.

Table 5. CONFIGURATION REGISTER BIT DESCRIPTIONS DONE = 0. Temperature conversion is in progress. DONE = 1. Temperature conversion is complete. a Software POR command is issued. Software POR command is issued. NVB = 0. NV memory is not busy. H, and TL resolution (see Table 6). H, and TL resolution (see Table 6). Power-up state = last value written to this bit. POL = 1. TOUT is active high. POL = 0. TOUT is active low. Power-up state = last value written to this bit. command initiates continuous temperature conversions. Table 6. RESOLUTION CONFIGURATION

interface to the bus through their SCL input pins and open-drain SDA I/O pins. device generates the SCL signal and START and STOP conditions. high by a pullup resistor (if the SCL output is open-drain). Transmitter: A device (master or slave) that is sending data on the bus. Receiver: A device (master or slave) that is receiving data from the bus. indicate that the master will perform another operation. 8). After the STOP is issued, the master releases the bus to its idle state.

2 A1 A0, where A2, A1, and A0 are user-selectable through

to be multidropped on the same bus. 1, and if the master is going to write data to the slave device then R/W･･ = 0. SET section of this data sheet. Figure 7. CONTROL BYTE

1001 A 2 A1 A0 R/W･･

Figure 8. START, STOP, AND ACK SIGNALS /g167 All data is transmitted MSb first over the 2-wire bus. /g167 One bit of data is transmitted on the 2-wire bus each SCL period. takes one SCL period. Therefore, nine clocks are required for every one-byte data transfer. an ACK after receiving the command byte.

The master can read data from the DS1631/DS1631A/D S1731 by issuing an Access Config, Access TH, Access TL, or Read Temperature command following the control byte (see Figures 9c and 9e). After receiving an ACK in response to the command, the ma ster must generate a repeated START followed by a control byte with the same slave address as the first control byte. However, this time the R/ W･･ bit must be a 1, which tells the DS1631/DS1631A/DS1731 that a “read” is being performed. After the DS1631/DS1631A/DS1731 send an ACK in response to this control byte, it begins transmitting the requested data on the next clock cycle. One byte of data will be transmitted when reading from the configuration register after which the master mu st respond with a NACK followed by a STOP. For two- byte reads (i.e., from the Temperature, T H, or T L register), the master must respond to the first data byte with an ACK and to the second byte with a NACK fo llowed by a STOP. If only the most significant byte of data is needed, the master can issue a NACK followed by a STOP after reading the first data byte. COMMAND SET The DS1631/DS1631A/DS1731 command set is detailed below: Start Convert T [ 51h ] Initiates temperature conversions. If the part is in one-shot mode (1SHOT = 1), only one conversion is performed. In continuous mode (1SHOT = 0), conti nuous temperature conversions are performed until a Stop Convert T command is issued. Stop Convert T [ 22h ] Stops temperature conversions when the device is in continuous conversion mode (1SHOT = 0). Read Temperature [ AAh ] Reads last converted temperature value from the 2-byte temperature register. Access TH [ A1h ] Reads or writes the 2-byte TH register. Access TL [ A2h ] Reads or writes the 2-byte TL register. Access Config [ ACh ] Reads or writes the 1-byte configuration register. Software POR [ 54h ] Initiates a software power-on-reset (POR), which stops temperature conversions and resets all registers and logic to their power-up states. The software POR allows the user to simulate cycling the power without actually powering down the device.

Figure 9 (a, b, c, d, e). 2-WIRE INTERFACE TIMING THERM = DS1631, DS1631A, or DS1731 a) Issue a "Start Convert T” or “Stop Convert T” Command S 11 00 A2 A1 A0 W AC 7 C 6 C 5 C 4 AC3 C1 C0 P Control Byte Command ByteSTART STOPACK (THERM) SCL SDA ACK (THERM) d) Write to the TH or TL Register A2 A1 A0 C2 SCL SDA S 1 10 0W A Control ByteSTART ACK (THERM) AC7 C6 C5 C4 C3 C1 C0 Command Byte ACK (THERM) D4D6 D5 D3 D2 D0D7D6 D5 D4 D3 D2 D1 D0D7 AD1 P LS Data Byte (from Master) A MS Data Byte (from Master) STOPACK (THERM) ACK (THERM) e) Read From the Temperature, TH, or TL Register AD 2 D 1 D 0D6 D5 D4 D3D7A2 A1 A000AC4 C3 C2 C1C7 C6 C5A2 A1 A0 A ACK (THERM) Repeat START A SCL SDA S 11 00 W Control ByteSTART Command Byte S 11 R Control Byte MS Data Byte (from THERM) ACK (THERM) ACK (THERM) ACK (Master) D5 ND6 D4 D3 D2 D1 D0 P LS Data Byte (from THERM) STOP NACK (Master) (THERM) (THERM) AD2D6 D5 D4 D3 D1 D0A0 W AA1 1 0 1 0 1 100A D 7A2 b) Write to the Configuration Register S1 1 00 Control ByteSTART SCL SDA ACK Command Byte P Data Byte (from Master) STOPACK ACK (THERM) NA1S1 1 00 A2 A1 A0 W 010 A 1 100 D6 D5 D4 D3 D2 D1 D0 PD7S1 100 A2 A1 A0 R A c) Read From the Configuration Register ACK (THERM) Repeat START SCL SDA Control ByteSTART Command Byte Data Byte (from THERM) STOPNACK (Master) Control ByteACK (THERM) ACK (THERM)

In this example, the master configures the DS1631/DS1631A/DS1731 (A 1A2A3 = 000) for continuous conversions and thermostatic function. MASTER MODE THERMETER* MODE DATA (MSb first) COMMENTS TX RX START START condition from MASTER. TX RX 90h MASTER sends control byte with R/ W･･ = 0. RX TX ACK Acknowledge bit from THERMOMETER. TX RX ACh MASTER sends Access Config command. RX TX ACK Acknowledge bit from THERMOMETER. TX RX 02h MASTER writes a data byte to the configuration register to put the THERMOMETER in continuous conversion mode and set the T OUT polarity to active high. RX TX ACK Acknowledge bit from THERMOMETER. TX RX STOP STOP condition from MASTER. TX RX START START condition from MASTER. TX RX 90h MASTER sends control byte with R/ W･･ = 0. RX TX ACK Acknowledge bit from THERMOMETER. TX RX A1h MASTER sends Access TH command. RX TX ACK Acknowledge bit from THERMOMETER. TX RX 28h MASTER sends most significant data byte for T H = +40°C. RX TX ACK Acknowledge bit from THERMOMETER. TX RX 00h MASTER sends least significant data byte for T H = +40°C. RX TX ACK Acknowledge bit from THERMOMETER. TX RX STOP STOP condition from MASTER. TX RX START START condition from MASTER. TX RX 90h MASTER sends control byte with R/ W･･ = 0. RX TX ACK Acknowledge bit from THERMOMETER. TX RX A2h MASTER sends Access TL command. RX TX ACK Acknowledge bit from THERMOMETER. TX RX 0Ah MASTER sends most significant data byte for T L = +10°C. RX TX ACK Acknowledge bit from THERMOMETER. TX RX 00h MASTER sends least significant data byte for T L = +10°C. RX TX ACK Acknowledge bit from THERMOMETER. TX RX STOP STOP condition from MASTER. TX RX START START condition from MASTER. TX RX 90h MASTER sends control byte with R/ W･･ = 0. RX TX ACK Acknowledge bit from THERMOMETER. TX RX 51h MASTER sends Start Convert T command. RX TX ACK Acknowledge bit from THERMOMETER. TX RX STOP STOP condition from MASTER. *THERMOMETER = DS1631, DS1631A, or DS1731