|
|
PDF DS1722 Data sheet ( Hoja de datos )
| Número de pieza | DS1722 | |
| Descripción | Digital Thermometer with SPI/3-Wire Interface | |
| Fabricantes | Dallas | |
| Logotipo |  |
|
Hay una vista previa y un enlace de descarga de DS1722 (archivo pdf) en la parte inferior de esta página. Total 13 Páginas | ||
|
No Preview Available !
www.dalsemi.com
PRELIMINARY
PRELIMINARY
DS1722
Digital Thermometer with
SPI/3-Wire Interface
FEATURES
Temperature measurements require no
external components
Measures temperatures from -55°C to
+120°C. Fahrenheit equivalent is -67°F to
+248°F
Thermometer accuracy is ±2.0°C
Thermometer resolution is configurable from
8 to 12 bits (1.0°C to 0.0625°C resolution)
Data is read from/written to via a Motorola
Serial Peripheral Interface (SPI) or standard
3-wire serial interface
Wide analog power supply range (2.65V -
5.5V)
Separate digital supply allows for 1.8V logic
Available in an 8-pin SOIC (150 mil), 8-pin
uSOP, and flip chip package
PIN ASSIGNMENT
VDDD 1 8 VDDA
VDDD
1*
8 VDDA
CE 2 7 SERMODE CE
2 7 SERMODE
SCLK 3 6 SDI
SCLK 3
6 SDI
GND 4 5 SDO
GND 4
5 SDO
DS1722S
8-Pin SOIC (150-mil)
DS1722U
8-PIN µ-SOP
PIN DESCRIPTION
SERMODE
- Serial Interface Mode
CE - Chip Enable
SCLK
- Serial Clock
GND
- Ground
VDDA
SDO
- Analog Supply Voltage
- Serial Data Out
SDI - Serial Data In
VDDD
- Digital Supply Voltage
DESCRIPTION
The DS1722 Digital Thermometer and Thermostat with SPI/3-Wire Interface provides temperature
readings which indicate the temperature of the device. No additional components are required; the device
is truly a temperature-to-digital converter. Temperature readings are communicated from the DS1722
over a Motorola SPI interface or a standard 3-wire serial interface. The choice of interface standard is
selectable by the user.
For applications that require greater temperature resolution, the user can adjust the readout resolution
from 8 to 12 bits. This is particularly useful in applications where thermal runaway conditions must be
detected quickly.
For application flexibility, the DS1722 features a wide analog supply rail of 2.65V - 5.5V. A separate
digital supply allows a range of 1.8V to 5.5V.
The DS1722 is available in an 8-pin SOIC (150-mil), 8-pin uSOP, and flip chip package.
Applications for the DS1722 include personal computers/servers/workstations, cellular telephones, office
equipment, or any thermally-sensitive system.
1 of 13
021500
1 page  
DS1722
CONFIGURATION REGISTER PROGRAMMING
The configuration register is accessed in the DS1722 with the 00h address for reads and the 80h address
for writes. Data is read from or written to the configuration register MSb first for SPI communication and
LSb first for 3-wire communication. The format of the register is illustrated in Figure 2. The effect each
bit has on DS1722 functionality is described below along with the power-up state of the bit. The entire
register is volatile, and thus it will power-up in the default state.
CONFIGURATION/STATUS REGISTER Figure 2
1
1
1
1SHOT
R2
MSb
R1
R0 SD
LSb
1SHOT = One-shot temperature conversion bit. If the SD bit is "1", (continuous temperature
conversions are not taking place), a "1" written to the 1SHOT bit will cause the DS1722 to perform one
temperature conversion and store the results in the temperature register at addresses 01h (LSB) and 02h
(MSB). The bit will clear itself to "0" upon completion of the temperature conversion. The user has
read/write access to the 1SHOT bit, although writes to this bit will be ignored if the SD bit is a "0",
(continuous conversion mode). The power-up default of the one-shot bit is "0".
R0, R1, R2 = Thermometer resolution bits. Table 4 below defines the resolution of the digital
thermometer, based on the settings of these 3 bits. There is a direct tradeoff between resolution and
conversion time, as depicted in the AC Electrical Characteristics. The user has read/write access to the
R2, R1 and R0 bits and the power-up default state is R2="0", R1="0", and R0="1" (9-bit conversions).
THERMOMETER RESOLUTION CONFIGURATION Table 4
R2 R1 R0
Thermometer Resolution
Max Conversion Time
000
8-bit
0.075s
001
9-bit
0.15s
010
10-bit
0.3s
011
11-bit
0.6s
1xx
12-bit
1.2s
x=Don’t care.
SD = Shutdown bit. If SD is "0", the DS1722 will continuously perform temperature conversions and
store the last completed result in the temperature register. If SD is changed to a "1", the conversion in
progress will be completed and stored and then the device will revert to a low-power shutdown mode.
The communication port remains active. The user has read/write access to the SD bit and the power-up
default is "1" (shutdown mode).
SERIAL INTERFACE
The DS1722 offers the flexibility to choose between two serial interface modes. The DS1722 can
communicate with the SPI interface or with a standard 3-wire interface. The interface method used is
determined by the SERMODE pin. When this pin is connected to VDDD SPI communication is selected.
When this pin is connected to ground, standard 3-wire communication is selected.
SERIAL PERIPHERAL INTERFACE (SPI)
The serial peripheral interface (SPI) is a synchronous bus for address and data transfer. The SPI mode of
serial communication is selected by tying the SERMODE pin to VDDD. Four pins are used for the SPI.
The four pins are the SDO (Serial Data Out), SDI (Serial Data In), CE (Chip Enable), and SCLK (Serial
Clock). The DS1722 is the slave device in an SPI application, with the microcontroller being the master.
5 of 13
5 Page 
TIMING DIAGRAM: 3-WIRE WRITE DATA TRANSFER Figure 10
DS1722
*I/O is SDI and SDO tied together.
AC ELECTRICAL CHARACTERISTICS: SPI Interface
PARAMETER
(-55°C to +120°C, 2.65V ≤=VDD ≤=5.5V)
SYMBOL CONDITION MIN TYP MAX UNITS NOTES
Data to SCLK Setup
SCLK to Data Hold
SCLK to Data Valid
SCLK Low Time
SCLK High Time
SCLK Frequency
SCLK Rise and Fall
CE to SCLK Setup
SCLK to CE Hold
CE Inactive Time
CE to Output High Z
tDC
tCDH
tCDD
tCL
tCH
tCLK
tR, tF
tCC
tCCH
tCWH
tCDZ
35 ns 5, 6
35 ns 5, 6
80 ns 5, 6, 7
100 ns 6
100 ns 6
DC
5.0 MHz
6
200 ns
400 ns 6
100 ns 6
400 ns 6
40 ns
5, 6
TIMING DIAGRAM: SPI READ DATA TRANSFER Figure 11
11 of 13
11 Page | ||
| Páginas | Total 13 Páginas | |
| PDF Descargar | [ Datasheet DS1722.PDF ] | |
Hoja de datos destacado
| Número de pieza | Descripción | Fabricantes |
| DS1720 | Digital Thermometer and Thermostat | Dallas |
| DS1721 | 2-Wire Digital Thermometer and Thermostat | Dallas |
| DS1722 | Digital Thermometer with SPI/3-Wire Interface | Dallas |
| DS1726 | High-Precision 3-Wire Digital Thermometer and Thermostat | Dallas |
| Número de pieza | Descripción | Fabricantes |
| SLA6805M | High Voltage 3 phase Motor Driver IC. |
 Sanken |
| SDC1742 | 12- and 14-Bit Hybrid Synchro / Resolver-to-Digital Converters. |
 Analog Devices |
|
DataSheet.es es una pagina web que funciona como un repositorio de manuales o hoja de datos de muchos de los productos más populares, |
| DataSheet.es | 2020 | Privacy Policy | Contacto | Buscar |