DS1821S+T&R datasheet, PDF - EEWORLD Datasheet

Datasheet> All Categories > The sensor> Sensor/transducer> DS1821S+T&R

DS1821S+T&R: DescriptionSerial Switch/Digital Sensor, 8 Bit(s), 1Cel, Rectangular, 8 Pin, Surface Mount, 0.208 INCH, ROHS COMPLIANT, SOP-8; CategoryThe sensor Sensor/transducer; File Size814KB，19 Pages; ManufacturerMaxim; Websitehttps://www.maximintegrated.com/en.html; Environmental Compliance

Download Datasheet Parametric View All

DS1821S+T&R Overview

Serial Switch/Digital Sensor, 8 Bit(s), 1Cel, Rectangular, 8 Pin, Surface Mount, 0.208 INCH, ROHS COMPLIANT, SOP-8

DS1821S+T&R Parametric

Parameter Name	Attribute value
Is it lead-free?	Lead free
Is it Rohs certified?	conform to
Maker	Maxim
package instruction	SOP8,.3
Reach Compliance Code	compliant
ECCN code	EAR99
Maximum accuracy (Celsius)	1 Cel
Other features	COMPLIANCE TO MIL-208
body width	5.28 mm
body height	1.98 mm
Body length or diameter	5.31 mm
shell	PLASTIC
JESD-609 code	e3
Installation features	SURFACE MOUNT
Number of digits	8
Number of terminals	8
Maximum working current	1 mA
Maximum operating temperature	125 °C
Minimum operating temperature	-55 °C
Output interface type	1-WIRE INTERFACE
Package body material	PLASTIC/EPOXY
Encapsulate equivalent code	SOP8,.3
Package Shape/Form	RECTANGULAR
power supply	3/5 V
Sensor/Transducer Type	TEMPERATURE SENSOR,SWITCH/DIGITAL OUTPUT,SERIAL
Maximum supply voltage	5.5 V
Minimum supply voltage	2.7 V
surface mount	YES
Terminal surface	Matte Tin (Sn)
Termination type	SOLDER
Base Number Matches	1

Preview

Download Datasheet

View All

19-6322; Rev 6/12

DS1821

Programmable Digital Thermostat and Thermometer

FEATURES



Requires no external components

Unique 1-Wire

interface requires only one

port pin for communication

Operates over a -55°C to +125°C (-67°F to

+257°F) temperature range

Functions as a standalone thermostat with

user-definable trip-points

Provides 8-bit (1°C resolution) centigrade

temperature measurements

Accuracy is

±1°C

over 0°C to +85°C range

Converts temperature to a digital word in

1 second (max)

Available in 3-pin TO92 and 8-pin SO

packages

Applications include thermostatic controls,

industrial systems, consumer products,

thermometers, or any thermally sensitive

system

PIN ASSIGNMENT

DS1821

1 2 3

GND

DS1821S

8-pin 208-mil SO

(DS1821S)

(BOTTOM VIEW)

TO92

(DS1821C)

PIN DESCRIPTION

GND

1-Wire is a registered trademark of Maxim Integrated

Products, Inc.

The DS1821 can function as a standalone thermostat with user-programmable trip-points or as 8-bit

temperature sensor with a 1-Wire digital interface. The thermostat trip-points are stored in nonvolatile

memory, so DS1821 units can be programmed prior to system insertion for true standalone operation.

The DS1821 has an operating temperature range of –55°C to +125°C and is accurate to

±1°C

over a range

of 0°C to +85°C. Communication with the DS1821 is accomplished through the open-drain DQ pin; this

pin also serves as the thermostat output.

1 of 19

DESCRIPTION

GND

1 2

- Ground

- Data In/Out and Thermostat Output

- Power Supply Voltage

- No Connect

DS1821

Nonvolatile write status can be monitored by reading the NVB bit in the status/configuration register:

NVB = 1 – a write to EEPROM memory is in progress, NVB = 0 – nonvolatile memory is idle.

THERMOSTAT MODE

In thermostat mode (T/R = 1), the DS1821 can operate as a standalone thermostat that triggers according

to the T

and T

trip-points programmed while the device was in 1-Wire mode. In thermostat mode the

DS1821 powers-up performing continuous temperature conversions, and the DQ pin acts as the

thermostat output. Detailed operation of the thermostat output is provided in the OPERATION –

STANDALONE THERMOSTAT section of this datasheet.

Communications can be re-established with the DS1821 while it is in thermostat mode by pulling V

0V while the DQ line is held high, and then toggling the DQ line low 16 times as shown in Figure 12.

This temporarily places the DS1821 in 1-Wire mode, allowing microprocessor communication with the

DS1821 via the DQ pin. At this time any I/O function can be performed, such as reading/writing the T

or configuration registers or reading the temperature register. To return to thermostat mode, the same

procedure can be performed (pulling V

to 0V while the DQ line is held high, and then clocking the DQ

line 16 times) or the power can be cycled. Note that temporarily putting the DS1821 into 1-Wire mode

does not change the power-up mode of the device; this can only be changed by rewriting the T/R bit in

the status/configuration register. Also note that holding both V

and DQ low for more than

approximately 10 seconds will cause the DS1821 to be powered down.

DS1821 output temperature data is calibrated in degrees centigrade and is stored in two’s complement

format in the 1-byte (8-bit) temperature register (see Figure 3), which the user can access when the

DS1821 is in 1-Wire mode (T/R = 0 in the status/configuration register). The sign bit (S) indicates if the

temperature is positive or negative; for positive numbers S = 0 and for negative numbers S = 1. Table 2

gives examples of digital output data and the corresponding temperature reading. For Fahrenheit

measurements, a lookup table or conversion routine must be used.

The DS1821 can be configured by the user to take continuous temperature measurements (continuous

conversion mode) or single measurements (one-shot mode). The desired configuration can be achieved

by setting the nonvolatile1SHOT bit in the status/configuration register: 1SHOT = 0 – continuous

conversion mode, 1SHOT = 1 – one-shot mode. Note that the 1SHOT setting only controls the operation

of the device in 1-Wire mode; in thermostat mode, continuous temperature conversions are started

automatically at power-up.

In continuous conversion mode, the Start Convert T [EEh] command initiates continuous temperature

conversions, which can be stopped using the Stop Convert T [22h] command. In one-shot mode the Start

Convert T [EEh] command initiates a single temperature conversion after which the DS1821 returns to a

low-power standby state. In this mode, the microprocessor can monitor the DONE bit in the

configuration register to determine when the conversion is complete: DONE = 0 ― conversion in

progress, DONE = 1 ― conversion complete. The DONE bit does not provide conversion status in

continuous conversion mode since measurements are constantly in progress (i.e., DONE will always be

0).

OPERATION – MEASURING TEMPERATURE

TEMPERATURE, T

and T

Figure 3

bit 7

bit 6

bit 5

bit 4

bit 3

bit 2

bit 1

bit 0

5 of 19

Recommended Resources

Automatic light control lighting circuit 2

Diode frequency conversion circuit

20KHz ring counter circuit diagram

Isolated Thermocouple Circuit with Cold Junction Compensation

Bipolar telephone circuit diagram

Anti-interference radar anti-theft alarm

【Classic Show】Smoke Alarm Circuit: [i=s]This post was last edited by dontium on 2015-1-23 13:27[/i]The smoke alarm consists of a series feedback photosensitive circuit composed of an infrared light-emitting tube and a phototransistor ,...; ddllxxrr Analogue and Mixed Signal

CN0163_【10 typical laboratory circuit recommendations】Part 4: [10 Typical Laboratory Circuit Recommendations] 4: ADXRS450 is a digital output gyroscope, mainly used in medical, industrial, instrumentation, stability and other high-performance applications. This ...; fish001 ADI Reference Circuit

Altium designer 18 steps to design circuit boards: We have previously introduced the general steps for using AD18 . This time, let’s briefly talk about an example of using AD18 to design a circuit board. Open AD18 , first create several project files,...; 电鱼电子工程师 PCB Design

Yamaha's new AV center uses ADI audio and video technology: Analog Devices, Inc. announced that Yamaha Corporation is leveraging ADI's Blackfin processor and three Advantiv Advanced TV Solutions ICs to deliver high-end functionality, flexibility and intuitive ...; songbo Analog electronics

Signal conditioning circuit: :victory: Signal conditioning circuit, ~ hope it is useful to everyone ~...; sunnyzhu12 DSP and ARM Processors

[ST NUCLEO-G071RB Review]_08_PWM timer control three-color LED experiment: [i=s]This post was last edited by lvxinn2006 on 2019-1-22 17:15[/i] [align=left][font=Tahoma]The development board evaluated in this event[/font]ST NUCLEO-G071RB is provided by STMicroelectronics. Tha...; lvxinn2006 stm32/stm8

Shortcut: A0 A1 A2 A3 A4 A5 A6 A7 A8 A9 AA AB AC AD AE AF AG AH AI AJ AK AL AM AN AO AP AQ AR AS AT AU AV AW AX AY AZ B0 B1 B2 B3 B4 B5 B6 B7 B8 B9 BA BB BC BD BE BF BG BH BI BJ BK BL BM BN BO BP BQ BR BS BT BU BV BW BX BY BZ C0 C1 C2 C3 C4 C5 C6 C7 C8 C9 CA CB CC CD CE CF CG CH CI CJ CK CL CM CN CO CP CQ CR CS CT CU CV CW CX CY CZ D0 D1 D2 D3 D4 D5 D6 D7 D8 D9 DA DB DC DD DE DF DG DH DI DJ DK DL DM DN DO DP DQ DR DS DT DU DV DW DX DZ

Popular Components