MAXIM DS1626, DS1726 Technical data

RST

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DESCRIPTION

The DS1626 and DS1726 digital thermometers/thermostats provide temperature measurements and stand-alone thermostat capability over a -55°C to +125°C range. The DS1626 offers ±0.5°C accuracy from 0°C to +70°C and the DS1726 has ±1°C accuracy from

-10°C to +85°C. The resolution of the measured temperature is user selectable from 9 to 12 bits. Communication with the DS1626 and DS1726 is achieved through a 3-wire serial bus.

The DS1626 and DS1726 offer thermostatic functionality with three dedicated thermostat outputs (T

HIGH

, T

, and T

LOW

), and

COM

overtemperature (TH) and undertemperature (TL) user-programmable thresholds stored in on-chip EEPROM. For stand-alone thermostat operation, TH and TL can be programmed prior to installation, and the DS1626/DS1726 can be configured to automatically begin taking temperature measurements at power-up. Table 1 summarizes the user-accessible registers. Figure 1 shows a functional diagram.

APPLICATIONS

Thermostatic Controls Industrial Controls Consumer Products Any Space-Constrained Thermally Sensitive

Application

High-Precision 3-Wire Digital

Thermometer and Thermostat

FEATURES

 Temperature Measurements Require No

External Components

 Measure Temperatures from -55°C to

+125°C (-67°F to +257°F)

 DS1626: ±0.5°C Accuracy from 0°C to

+70°C

 DS1726: ±1°C Accuracy from -10°C to

+85°C

 Output Resolution is User Selectable to 9,

10, 11, or 12 Bits

 Wide Power-Supply Range (2.7V to 5.5V)  Convert Temperature to Digital Word in

750ms (max)

 Stand-Alone Thermostat Capability  Thermostatic Settings are User Definable and

Nonvolatile (NV)

 Data is Read/Written Through a 3-Wire

Serial Interface

 Available in 8-Pin μSOP Package

PIN CONFIGURATION

TOP VIEW

CLK/CN

GND

ORDERING INFORMATION

PART TEMP RANGE PIN-PACKAGE TOP MARK

DS1626U -55°C to +125°C

DS1626U+ -55°C to +125°C DS1626U/T&R -55°C to +125°C DS1626U+T&R -55°C to +125°C DS1726U -55°C to +125°C DS1726U+ -55°C to +125°C DS1726U/T&R -55°C to +125°C DS1726U+T&R -55°C to +125°C

+Denotes a lead-free package. A “+” symbol will also be marked on the package near the Pin 1 indicator. T&R = Tape and reel.

8 μSOP 8 μSOP 8 μSOP, 3000-Piece 8 μSOP, 3000-Piece 8 μSOP 8 μSOP 8 μSOP, 3000-Piece 8 μSOP, 3000-Piece

DS1626/DS1726

VDD

HIGH

LOW

COM

1626 1626 1626 1626 1726 1726 1726 1726

2 3

DS1626 DS1726

SOP

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CNV

PIN DESCRIPTION

PIN NAME FUNCTION

1 DQ Data Input/Output Pin (Tri-State) for 3-Wire Serial Communication 2 3

CLK/CNV

RST

Clock Input Pin for 3-Wire Serial Communication. Controls temperature measurements when the DS1626/DS1726 is configured as a stand-alone thermostat.

Reset Input Pin for 3-Wire Serial Communication 4 GND Ground Pin 5 T 6 T 7 T

Thermostat Output Pin (Push-Pull) with Programmable Hysteresis

COM

Thermostat Output Pin (Push-Pull) with TL Trip Point

LOW

Thermostat Output Pin (Push-Pull) with TH Trip Point

HIGH

8 VDD Supply Voltage. +2.7V to +5.5V input power pin.

Table 1. DS1626/DS1726 REGISTER SUMMARY

(USER ACCESS)

Temperature

(Read Only)

(Read/Write)

Configuration

(Various Bits are

Read/Write and Read

Only—See Table 3)

SIZE

12 Bits SRAM

12 Bits EEPROM

1 Byte

MEMORY

TYPE

SRAM and

EEPROM

AND POWER-UP/POR STATE

Measured Temperature (Two’s Complement) Power-Up/POR State: -60ºC (1100 0100 0000) Upper Alarm Trip Point (Two’s Complement) Power-Up/POR State: User Defined Initial State from Factory: +15°C (0000 1111 0000) Lower Alarm Trip Point (Two’s Complement) Power-Up/POR State: User Defined Initial State from Factory: +10°C (0000 1010 0000) Configuration and Status Information (Unsigned) 4MSbs = SRAM and 4LSbs = EEPROM Power-Up/POR State: 1000XXXX (XXXX = User Defined)

Figure 1. DS1626/DS1726 FUNCTIONAL DIAGRAM

VDD

CONFIGURATION REGISTER AND CONTROL LOGIC

CLK/

ADDRESS

and

I/O CONTROL

SDA

TEMPERATURE SENSOR AND ΔΣ ADC

TEMPERATURE REGISTER

COMPARATOR/LOGIC

TL REGISTER

DIGITAL

DS1626/DS1726

T T

LOW

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DS1626/DS1726

ABSOLUTE MAXIMUM RATINGS

Voltage Range 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).............................................................................................+260°C

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

= 2.7V to 5.5V, TA = -55°C to +125°C.)

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

Supply Voltage VDD DS1626

Thermometer Error

ERR

(Note 2)

DS1726 Thermometer

ERR

Error (Note 2)

Low-Level Input Voltage High-Level Input Voltage Input Current each Input Pin

Active Supply Current (Note 3)

VIL (Note 1) -0.5 0.3 x V

VIH (Note 1) 0.7 x V

0.4 < V

Input Resistance RI Standby Supply

Current

STBY

VOH 1mA source current 2.4 THIGH, TLOW, TCOM, DQ Output Logic

Voltages (Note 1) Thermal Drift

0°C to +70°C (Note 3) 1.5 µA

4mA sink current 0.4

(Note 1) 2.7 5.5 V 0°C to +70°C,

3.0V ≤ V

≤ 5.5V

0°C to +70°C,

2.7V ≤ V

< 3.0V

-55°C to +125°C

-10°C to +85°C,

3.0V ≤ V

≤ 5.5V

-10°C to +85°C,

2.7V ≤ V

< 3.0V

±0.5

±1.25

±1.5

°C

±2 ±1

°C

-55°C to +125°C ±2 V

< 0.9 x VDD -10 +10 µA

I/O

Temperature conversion

-55°C to +85°C

Temperature conversion +85°C to +125°C

+ 0.3 V

1.25

E2 write 400 µA RST to GND DQ, CLK to V

MΩ

(Note 4)

±0.2 °C

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DS1626/DS1726

EEPROM AC ELECTRICAL CHARACTERISTICS

= 2.7V to 5.5V, TA = -55°C to +125°C.)

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

EEPROM Write Cycle Time twr 4 10 ms EEPROM Writes N EEPROM Data Retention t

-55°C to +55°C 50k Writes

EEWR

-55°C to +55°C 10 Years

EEDR

AC ELECTRICAL CHARACTERISTICS

= 2.7V to 5.5V, TA = -55°C to +125°C.)

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

9 bits 93.75

Temperature Conversion Time tTC

10 bits 187.5 11 bits 375

12 bits 750 Data In to Clock Setup tDC (Note 5) 35 ns Clock to Data In Hold t Clock to Data Out Delay t

(Note 5) 40 ns

CDH

(Notes 5, 6) 150 ns

CDD

Clock Low/High Time tCL, tCH (Note 5) 285 ns Clock Frequency f

(Note 5) 0 1.75 MHz

CLK

Clock Rise/Fall Time tR, tF (Note 5) 500 ns RST to Clock Setup Clock to RST Hold RST Inactive Time Clock High to I/O Hi-Z t

RST Low to I/O Hi-Z CNV Pulse Width

I/O Capacitance C

tRC (Note 5) 100 ns

(Note 5) 40 ns

CRH

tRI (Note 7) 125 ns

(Note 5) 50 ns

CDZ

(Note 5) 50 ns

RDZ

(Note 8) 250ns 500ms

CNV

I/O

10 pF Input Capacitance CI 5 pF

NOTES:

1) All voltages are referenced to ground.

2) See Figure 2 for TYPICAL OPERATING CURVES.

3) I

4) Drift data is based on a 1000hr stress test at +125°C with V

5) See Timing Diagrams in Figure 3. All timing is referenced to 0.7 x V

6) Load capacitance = 50pF.

7) tRI must be 10ms minimum following any write command that involves the E2 memory.

8) 250ns is the guaranteed minimum pulse width for a conversion to start, however, a smaller pulse

, IDD specified with DQ, CLK/CNV = VDD and RST = GND.

STBY

width may start a conversion.

= 5.5V.

and 0.3 x VDD.

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