Datasheet

ManualsBrandsMAXIM INTEGRATED ManualsPMICsDS1631AU+

See Table 2 for Pin Descriptions.

General Description

The DS1631, DS1631A, and DS1731 digital thermome-

ters provide 9, 10, 11, or 12-bit temperature readings over

a -55°C to +125°C range. The DS1631 and DS1631A

thermometer accuracy is ±0.5°C from 0°C to +70°C with

3.0V ≤ V

≤ 5.5V, and the DS1731 accuracy is ±1°C

from -10°C to +85°C with 3.0V ≤ V

≤ 5.5V. The ther-

mostat on all three devices provides custom hysteresis

with user-defined trip points (T

and T

). The T

and

registers and thermometer configuration settings are

stored in NV EEPROM so they can be programmed prior

to installation. In addition, the DS1631A automatically

begins taking temperature measurements at power-up,

which allows it to function as a stand-alone thermostat.

Pin descriptions for the DS1631/DS1631A/DS1731 are pro-

vided in Table 2 and user-accessible registers are summa-

rized in Table 3. A functional diagram is shown in Figure 1.

Applications

● Network Routers and Switches

● Cellular Base Stations

● Portable Products

● Any Space-Constrained Thermally Sensitive Product

Benets and Features

● Maximize System Accuracy in Broad Range of

Thermal Management Applications

• Operating Temperature Range: -55°C to +125°C

(-67°F to +257°F)

• DS1631 and DS1631A: ±0.5°C Accuracy over 0°C

to +70°C Range

• DS1731: ±1°C Accuracy over a -10°C to +85°C Range

• User-Selectable Output Resolution from 9 Bits to

12 Bits

● Reduce Cost with No External Components

● Simplify Distributed Temperature-Sensing Applications

with Multidrop Capability

• Up to Eight Devices Can Operate on a 2-Wire Bus

● Flexible and Nonvolatile User-Defined Thermostatic

Modes with Custom Hysteresis

● Available in 8-Pin µSOP and SO (DS1631 and

DS1631A Only) and the 8-Pin DIP (DS1631 Only)

Packages

Ordering Information appears at end of data sheet.

19-7488; Rev 1; 1/15

Pin Congurations

SDA

SCL

OUT

GND

DS1631

µSOP

(DS1631U+, DS1631AU+, DS1731U+)

TOP VIEW

SDA

SCL

OUT

GND

DS1631

SO (150mil and 208mil)

(DS1631Z+, DS1631S+)

DS1631/DS1631A/

DS1731

High-Precision Digital

Thermometer and Thermostat

Summary of content (14 pages)

PAGE 1
DS1631/DS1631A/ DS1731 High-Precision Digital Thermometer and Thermostat General Description The DS1631, DS1631A, and DS1731 digital thermometers provide 9, 10, 11, or 12-bit temperature readings over a -55°C to +125°C range. The DS1631 and DS1631A thermometer accuracy is ±0.5°C from 0°C to +70°C with 3.0V ≤ VDD ≤ 5.5V, and the DS1731 accuracy is ±1°C from -10°C to +85°C with 3.0V ≤ VDD ≤ 5.5V. The thermostat on all three devices provides custom hysteresis with user-defined trip points (TH and TL).
PAGE 2
DS1631/DS1631A/ DS1731 High-Precision Digital Thermometer and Thermostat 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................................................
PAGE 3
DS1631/DS1631A/ DS1731 High-Precision Digital Thermometer and Thermostat AC Electrical Characteristics (VDD = 2.7V to 5.5V; TA = -55°C to +125°C.) PARAMETER SYMBOL Temperature Conversion Time tTC SCL Frequency fSCL Bus Free Time Between a STOP and START Condition tBUF CONDITION MIN TYP 9-bit resolution 93.75 10-bit resolution 187.5 11-bit resolution 375 12-bit resolution START and Repeated START Hold Time from Falling SCL tHD:STA MAX UNITS ms 750 0 400 kHz (Note 5) 1.
PAGE 4
DS1631/DS1631A/ DS1731 High-Precision Digital Thermometer and Thermostat Table 2. Detailed Pin Description PIN SYMBOL 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. 3 TOUT Thermostat Output Pin. Push-Pull. 4 GND Ground Pin 5 A2 Address Input Pin 6 A1 Address Input Pin 7 A0 Address Input Pin 8 VDD Supply Voltage Pin. +2.7V to +5.5V Power-Supply Pin.
PAGE 5
DS1631/DS1631A/ DS1731 High-Precision Digital Thermometer and Thermostat ALL TIMING IS REFERENCED TO 0.9 X VDD AND 0.1 x VDD. SDA tBUF tLOW tSP tR tHD:STA tF SCL tSU:STO tHD:STA tSU:STA tHD:DAT STOP tHIGH tSU:DAT REPEATED START START Figure 3. Timing Diagram Table 3. Register Summary REGISTER NAME (USER ACCESS) SIZE (BYTES) MEMORY TYPE Temperature (Read Only) 2 SRAM Measured temperature in two’s complement format.
PAGE 6
DS1631/DS1631A/ DS1731 High-Precision Digital Thermometer and Thermostat Operation—Measuring Temperature The resolution of the output digital temperature data is user-configurable to 9, 10, 11, or 12 bits, corresponding to temperature increments of 0.5°C, 0.25°C, 0.125°C, and 0.0625°C, respectively. The default resolution at powerup is 12 bits, and it can be changed through the R0 and R1 bits in the configuration register. Note that the conversion time doubles for each additional bit of resolution.
PAGE 7
DS1631/DS1631A/ DS1731 Operation—Thermostat Function The thermostat output (TOUT) is updated after every temperature conversion, based on a comparison between the measured digital temperature and user-defined upper and lower thermostat trip points. TOUT remains at the updated value until the next conversion completes.
PAGE 8
DS1631/DS1631A/ DS1731 High-Precision Digital Thermometer and Thermostat Table 5. Configuration Register Bit Descriptions BIT NAME (USER ACCESS) FUNCTIONAL DESCRIPTION DONE—Temperature Conversion Done (Read Only) Power-up state = 1. DONE = 0. Temperature conversion is in progress. DONE = 1. Temperature conversion is complete. THF—Temperature High Flag (Read/Write) Power-up state = 0. THF = 0. The measured temperature has not exceeded the value stored in the TH register since power-up. THF = 1.
PAGE 9
DS1631/DS1631A/ DS1731 2-Wire Serial Data Bus The DS1631, DS1631A, and DS1731 communicate over a bidirectional 2-wire serial data bus that consists of a serial clock (SCL) signal and serial data (SDA) signal. The DS1631, DS1631A, and DS1731 interface to the bus through their SCL input pins and open-drain SDA I/O pins. The following terminology is used to describe 2-wire communication: High-Precision Digital Thermometer and Thermostat for an entire SCL period (see Figure 8).
PAGE 10
DS1631/DS1631A/ DS1731 General 2-Wire Information ●● All data is transmitted MSb first over the 2-wire bus. ●● One bit of data is transmitted on the 2-wire bus each SCL period. ●● A pullup resistor is required on the SDA line and, when the bus is idle, both SDA and SCL must remain in a logic-high state. ●● All bus communication must be initiated with a START condition and terminated with a STOP condition. During a START or STOP is the only time SDA is allowed to change states while SCL is high.
PAGE 11
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PAGE 12
DS1631/DS1631A/ DS1731 High-Precision Digital Thermometer and Thermostat Operation Example In this example, the master configures the DS1631/DS1631A/DS1731 (A1A2A3 = 000) for continuous conversions and thermostatic function. MASTER MODE THERMETER* MODE DATA (MSB FIRST) TX RX START COMMENTS 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.
PAGE 13
DS1631/DS1631A/ DS1731 High-Precision Digital Thermometer and Thermostat Table 1.
PAGE 14
DS1631/DS1631A/ DS1731 High-Precision Digital Thermometer and Thermostat Revision History REVISION NUMBER REVISION DATE 0 10/07 Initial release — 1 1/15 Updated Benefits and Features section 1 DESCRIPTION PAGES CHANGED For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim Integrated’s website at www.maximintegrated.com.