Datasheet

ManualsBrandsMAXIM INTEGRATED ManualsPMICsDS7505U+

General Description

The DS7505 low-voltage (1.7V to 3.7V) digital thermom-

eter and thermostat provides 9-, 10-, 11-, or 12-bit digital

temperature readings over a -55°C to +125°C range with

±0.5°C accuracy over a -0°C to +70°C range. A 9-bit reso-

lution mode is software compatible with the LM75.

The DS7505 thermostat has a dedicated open-drain

output (O.S.) and programmable fault tolerance, which

allows the user to define the number of consecutive error

conditions that must occur before O.S. is activated. There

are two thermostatic operating modes that control thermo-

stat operation based on user-defined trip points (T

and

HYST

) that are stored in EEPROM registers.

Applications

● Networking Equipment

● Cellular Base Stations

● Ofce Equipment

● Medical Equipment

● Any Thermally Sensitive System

Benets and Features

● Extends Performance Range with a Low-Voltage,

1.7V to 3.7V Operating Range

● Maximizes System Accuracy in Broad Range of

Thermal Management Applications

• Measures Temperature from -55°C to +125°C

(-67°F to +257°F)

• ±0.5°C Accuracy Over a 0°C to +70°C Range

• User-Congurable Resolution from 9 Bits (Default)

to 12 Bits (0.5°C to 0.0625°C Resolution)

● Reduces Cost with No External Components and

Stand Alone Thermostat Capability

● Increases Reliability and System Robustness

• Internally Filtered Data Lines for Noise Immunity

(50ns Deglitch)

• Bus Timeout Feature Prevents Lockup on a 2-Wire

Interface

● Simplifies Distributed Temperature-Sensing

Applications with Multidrop Capability

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

● Fast 25ms (max) 9-Bit Conversion Time

● Flexible and Nonvolatile (NV) User-Defined

Thermostatic Mode

μMAX is a registered trademark of Maxim Integrated Products,

Inc.

Commands are capitalized for clarity.

19-7471; Rev 2; 12/14

+Denotes a lead(Pb)-free/RoHS-compliant package.

T&R = Tape and reel.

PART TEMP RANGE PIN-PACKAGE

DS7505S+ -55°C to +125°C 8 SO (150 mils)

DS7505S+T&R -55°C to +125°C

8 SO (150 mils),

2500-Piece T&R

DS7505U+ -55°C to +125°C 8 µMAX®

DS7505U+T&R -55°C to +125°C

8 µMAX,

3000-Piece T&R

TOP VIEW

2 7 A0SCL

1 8 VDDSDA

O.S. 3 6

A2GND

4 5

DS7505

µMAX

2 7 A0SCL

1 8 VDDSDA

A1O.S. 3 6

A2GND 4 5

DS7505

DS7505 Digital Thermometer and Thermostat

Pin Congurations

Ordering Information

Summary of content (14 pages)

PAGE 1
DS7505 Digital Thermometer and Thermostat General Description The DS7505 low-voltage (1.7V to 3.7V) digital thermometer and thermostat provides 9-, 10-, 11-, or 12-bit digital temperature readings over a -55°C to +125°C range with ±0.5°C accuracy over a -0°C to +70°C range. A 9-bit resolution mode is software compatible with the LM75. The DS7505 thermostat has a dedicated open-drain output (O.S.
PAGE 2
DS7505 Digital Thermometer and Thermostat Absolute Maximum Ratings Voltage Range on VDD Relative to Ground..........-0.3V to +4.0V Voltage Range on Any Other Pin Relative to Ground............................................-0.3V to +6.0V Operating Temperature Range.......................... -55°C to +125°C Storage Temperature Range............................. -55°C to +125°C Soldering Temperature.......................... Refer to the IPC/JEDEC J-STD-020 Specification.
PAGE 3
DS7505 Digital Thermometer and Thermostat AC Electrical Characteristics (continued) (1.7V ≤ VDD ≤ 3.7V, TA = -55°C to +125°C, unless otherwise noted.) PARAMETER EEPROM Data Retention Bus Free Time Between a STOP and START Condition START and Repeated START Hold Time from Falling SCL SYMBOL tEEDR tBUF tHD:STA CONDITIONS MIN TYP MAX UNITS -40°C to +125°C (Note 8) 10 Years (Note 9) 1.3 µs (Notes 9, 10) 600 ns Low Period of SCL tLOW (Note 9) 1.3 µs High Period of SCL tHIGH (Note 9) 0.
PAGE 4
DS7505 Digital Thermometer and Thermostat Pin Description PIN NAME FUNCTION 1 SDA Data Input/Output. For 2-wire serial communication port. Open drain. 2 SCL Clock Input. For 2-wire serial communication port. 3 O.S. Thermostat Output. Open drain. 4 GND Ground 5 A2 Address Input 6 A1 Address Input 7 A0 Address Input 8 VDD Supply Voltage. +1.7V to +3.7V supply pin. SDA tF tLOW tSU:DAT tR tF tSP tR tBUF tHD:STA SCL tHD:STA tSU:STA tHD:DAT tSU:STO SR P S Figure 1.
PAGE 5
DS7505 Digital Thermometer and Thermostat Operation—Measuring Temperature After each temperature measurement and analog-todigital (A/D) conversion, the DS7505 stores the temperature as a 16-bit two’s complement number in the 2-byte temperature register (see Figure 3). The sign bit (S) indicates if the temperature is positive or negative: for positive numbers S = 0 and for negative numbers S = 1. The most recently converted digital measurement can be read from the temperature register at any time.
PAGE 6
DS7505 Shutdown Mode For power-sensitive applications, the DS7505 offers a low-power shutdown mode. The SD bit in the configuration register controls shutdown mode. When SD is programmed to 1, the conversion in progress is completed and the result stored in the temperature register, after which the DS7505 goes into a low-power standby state. The O.S. output is cleared if the thermostat is operating in interrupt mode and O.S remains unchanged in comparator mode.
PAGE 7
DS7505 Digital Thermometer and Thermostat IN THIS EXAMPLE, THE DS7505 IS CONFIGURED TO HAVE A FAULT TOLERANCE OF 2. TOS TEMPERATURE THYST INACTIVE O.S. OUTPUT—COMPARATOR MODE ACTIVE INACTIVE O.S. OUTPUT—INTERRUPT MODE ACTIVE ASSUMES A READ HAS OCCURED CONVERSIONS Figure 4. O.S. Output Operation Example Interrupt Mode In interrupt mode, the O.S.
PAGE 8
DS7505 Digital Thermometer and Thermostat Configuration Register The configuration register allows the user to program various DS7505 options such as conversion resolution, thermostat fault tolerance, thermostat polarity, thermostat operating mode, and shutdown mode. The configuration register is arranged as shown in Figure 5 and detailed descriptions of each bit are provided in Table 2.
PAGE 9
DS7505 Digital Thermometer and Thermostat 2-Wire Serial Data Bus Table 3. Resolution Configuration R1 R0 THERMOMETER RESOLUTION (BITS) MAX CONVERSION TIME (ms) 0 0 9 25 0 1 10 50 1 0 11 100 1 1 12 200 Table 4. Fault Tolerance Configuration F1 F0 CONSECUTIVE OUT-OF-LIMITS CONVERSIONS TO TRIGGER O.S. 0 0 1 0 1 2 1 0 4 1 1 6 The four DS7505 registers each have a unique 2-bit pointer designation, which is defined in Table 5.
PAGE 10
DS7505 Digital Thermometer and Thermostat Slave Address: Every slave device on the bus has a unique 7-bit address that allows the master to access that device. The DS7505’s 7-bit bus address is 1 0 0 1 A2 A1 A0, where A2, A1, and A0 are user-selectable through the corresponding input pins. The three address pins allow up to eight DS7505s to be multidropped on the same bus.
PAGE 11
DS7505 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 12
DS7505 Digital Thermometer and Thermostat Copy Data [48h] 0100 1000 Software POR [54h] Copies data from all SRAM shadow registers to EEPROM. It is recommended that a Copy Data command be performed after writing EEPROM-backed memory locations to guarantee data integrity in the event of a power loss. The master sends a START followed by an address byte containing the DS7505 bus address. The R/W bit must be a 0. The DS7505 responds with an ACK.
PAGE 13
DS7505 Digital Thermometer and Thermostat Package Information For the latest package outline information and land patterns (footprints), go to www.maximintegrated.com/packages. Note that a “+”, “#”, or “-” in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing pertains to the package regardless of RoHS status. PACKAGE TYPE PACKAGE CODE DOCUMENT NO. 8 SO S8+2 21-0041 8 μMAX U8+3 21-0036 www.maximintegrated.
PAGE 14
DS7505 Digital Thermometer and Thermostat Revision History REVISION NUMBER REVISION DATE PAGES CHANGED 0 2/08 Initial release. 1 3/08 Removed references to exposed pad (µMAX package does not have an EP); corrected package information outline document number. 2 12/14 Updated General Description and Benefits and Features sections DESCRIPTION — 1, 4, 13 2 For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim Integrated’s website at www.