DS1631.pdf 데이터시트 (총 14 페이지) - 파일 다운로드 DS1631 데이타시트 다운로드

No Preview Available !

www.maxim-ic.com
DS1631
±0.5°C Accuracy Digital
Thermometer and Thermostat
FEATURES
§ Temperature measurements require no
external components
§ Measures temperatures from -55°C to +125°C
(-67°F to +257°F)
§ ±0.5°C accuracy over a range of 0°C to
+70°C
§ Output resolution is user-selectable to 9, 10,
11, or 12 bits
§ Wide power-supply range (2.7V to 5.5V)
§ Converts temperature to digital word in
750ms (max)
§ Multidrop capability simplifies distributed
temperature-sensing applications
§ Thermostatic settings are user-definable and
nonvolatile (NV)
§ Data is read/written through a 2-wire serial
interface (SDA and SCL pins)
§ Applications include thermostatic controls,
industrial systems, consumer products,
thermometers, or any thermally sensitive
system
§ Available in 8-pin mSOP, SO (150mil and
208mil), and PDIP packages (see Table 1 for
ordering information)
PIN ASSIGNMENT
SDA 1
8 VDD
SCL 2
7 A0
TOUT
3
6 A1
GND 4
5 A2
DS1631Z—8-pin SO (150mil)
SDA
SCL
TOUT
GND
1
2
3
4
8 VDD
7 A0
6 A1
5 A2
DS1631U—mSOP
Note: Pin assignments for the
DS1631S (208mil 8-Pin SO) and
DS1631 (8-Pin PDIP) are the same
as for the DS1631Z.
PIN DESCRIPTION
SDA - Open-Drain Data I/O
SCL - Clock Input
TOUT - Thermostat Output
GND - Ground
VDD - Power Supply
A0 - Address Input
A1 - Address Input
A2 - Address Input
DESCRIPTION
The DS1631 digital thermometer and thermostat provides 9-, 10-, 11-, or 12-bit digital temperature
readings over a range of -55°C to +125°C. The thermometer accuracy is ±0.5°C from 0°C to +70°C with
3.0V £ VDD £ 5.5V. The thermostat provides custom hysteresis with user-defined trip points (TH and TL).
The thermostat output (TOUT) becomes active when the temperature of the device exceeds the upper
thermostat trip point (TH), and remains active until the temperature drops below the lower thermostat trip
point (TL).
The TH and TL registers and thermometer configuration settings are stored in NV EEPROM so the
DS1631 can be programmed prior to installation. Communication with the DS1631 is achieved through a
standard 2-wire serial interface.
1 of 14
071502

No Preview Available !

ORDERING INFORMATION Table 1
Ordering Number Package Marking Description
DS1631U
D1631
8-pin mSOP
DS1631U/T&R
D1631
8-pin mSOP, 3000 piece tape and reel
DS1631Z
DS1631Z
150mil 8-pin SO
DS1631Z/T&R
DS1631Z
150mil 8-pin SO, 2500 piece tape and reel
DS1631S
DS1631S
208mil 8-pin SO
DS1631S/T&R
DS1631S
208mil 8-pin SO, 2000 piece tape and reel
DS1631
DS1631
8-pin PDIP
DS1631
DETAILED PIN DESCRIPTION Table 2
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. +2.7V to +5.5V input power pin.
DS1631 FUNCTIONAL BLOCK DIAGRAM Figure 1
VDD
GND
CONFIGURATION REGISTER
AND CONTROL LOGIC
SCL
SDA
A0
A1
A2
ADDRESS
AND
I/O CONTROL
TEMPERATURE SENSOR
TH REGISTER
TL REGISTER
DIGITAL
COMPARATOR/LOGIC
TOUT
OVERVIEW
The DS1631 measures temperature using a bandgap-based temperature sensor. A delta-sigma analog-to-
digital converter (ADC) converts the measured temperature to a 9-, 10-, 11-, or 12-bit (user selectable)
digital value that is calibrated in degrees centigrade; for Fahrenheit applications a lookup table or
conversion routine must be used. The DS1631 also provides thermostat capability with user-
programmable NV trip-point registers. Communication with the DS1631 is achieved through a standard
2-wire serial interface. Detailed DS1631 pin descriptions are provided in Table 2 and user-accessible
registers are summarized in Table 3. A DS1631 block diagram is shown in Figure 1
2 of 14

No Preview Available !

DS1631
DS1631 REGISTER SUMMARY Table 3
REGISTER USER ACCESS SIZE MEMORY
NAME
TYPE
Temperature
(Read Only) 2 bytes SRAM
TH (Read/Write) 2 bytes EEPROM
TL (Read/Write) 2 bytes EEPROM
Configuration
(Read/Write, but
some bits are
Read Only—see
Table 7)
1 byte SRAM and
EEPROM
REGISTER CONTENTS
AND POWER-UP/POR STATE
Measured temperature in two’s
complement format.
Power-up/POR state: -60ºC (1100 0100
0000 0000)
Upper alarm trip-point in two’s
complement format.
Power-up/POR state: user defined.
Lower alarm trip-point in two’s
complement format.
Power-up/POR state: user defined.
Configuration and status information.
Unsigned data.
6 MSbs = SRAM
2 LSbs (POL and 1SHOT bits) =
EEPROM
Power-up/POR state: 100011XX (XX =
User defined)
OPERATION—MEASURING TEMPERATURE
The DS1631 can be programmed to take continuous temperature measurements (continuous conversion
mode) or to take single temperature measurements on command (one-shot mode). The measurement
mode is programmed through the 1SHOT bit in the configuration register: 1SHOT = 1—one-shot mode;
1SHOT = 0—continuous conversion mode. The 1SHOT bit is stored in NV EEPROM, so it can be
programmed prior to installation if desired. In continuous conversion mode, when a Start Convert T
command is issued, the DS1631 will perform consecutive temperature measurements until a Stop Convert
T command is issued. In one-shot mode, the Start Convert T command causes one temperature
measurement to be taken, then the DS1631 returns to a low-power idle state. One-shot mode is
recommended for use in power-sensitive applications.
The resolution of the DS1631 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 power-up is 12 bits, and it can be changed through the R0 and R1 bits in the
configuration register as explained in the CONFIGURATION REGISTER section of this data sheet. Note
that the conversion time doubles for each additional bit of resolution.
After each temperature measurement and analog-to-digital conversion, the DS1631 stores the temperature
as a 16-bit two’s complement number in the 2-byte temperature register (see Figure 2). The sign bit (S)
indicates if the temperature is positive or negative: for positive numbers S = 0 and for negative numbers S
= 1. The Read Temperature command provides user access to the temperature register.
Bits 3 through 0 of the temperature register are hardwired to 0. When the DS1631 is configured for 12-bit
resolution, the 12 MSbs (bits 15 through 4) of the temperature register will contain temperature data. For
11-bit resolution, the 11 MSbs (bits 15 through 5) of the temperature register will contain data, and bit 4
will read out as 0. Likewise, for 10-bit resolution, the 10 MSbs (bits 15 through 6) will contain data, and
for 9-bit the 9 MSbs (bits 15 through 7) will contain data, and all unused LSbs will contain 0s. Table 4
gives examples of 12-bit resolution digital output data and the corresponding temperatures.
3 of 14

No Preview Available !

TEMPERATURE, TH, and TL REGISTER FORMAT Figure 2
MS Byte
bit 15
S
bit 14
26
bit 13
25
bit 12
24
bit 11
23
bit 10
22
bit 7 bit 6 bit 5 bit 4 bit 3 bit 2
LS Byte
2-1
2-2
2-3
2-4
0
0
DS1631
bit 9 bit 8
21 20
bit 1 bit 0
00
12-BIT RESOLUTION TEMPERATURE/DATA RELATIONSHIP Table 4
TEMPERATURE
(°C)
+125
+25.0625
DIGITAL OUTPUT
(BINARY)
0111 1101 0000 0000
0001 1001 0001 0000
DIGITAL OUTPUT
(HEX)
7D00h
1910h
+10.125
0000 1010 0010 0000
0A20h
+0.5 0000 0000 1000 0000
0080h
0
0000 0000 0000 0000
0000h
-0.5 1111 1111 1000 0000 FF80h
-10.125
1111 0101 1110 0000
F5E0h
-25.0625
1110 0110 1111 0000
E6F0h
-55 1100 1001 0000 0000 C900h
OPERATION—THERMOSTAT FUNCTION
The DS1631 thermostat output (TOUT) is updated after every temperature conversion, and remains at the
updated value until the next conversion completes. TOUT is activated and deactivated based on user-
defined upper and lower trip points. When the measured temperature meets or exceeds the value stored in
the upper trip-point register (TH), TOUT will become active and stay active until the temperature falls
below the value stored in the lower trip-point register (TL) (see Figure 3). This allows the user to program
any amount of hysteresis into the output response. The active state of TOUT is user-programmable through
the polarity bit (POL) in the configuration register: POL = 1—TOUT is active high; POL = 0—TOUT is
active low.
The user-defined values in the TH and TL registers (see Figure 2) must be in two’s complement format
with the MSb (bit 15) containing the sign bit (S). The resolution of the TH and TL values is determined by
the R0 and R1 bits in the configuration register (see Table 5), so the TH and TL resolution will match the
output temperature resolution. For example, for 10-bit resolution bits 5 through 0 of the TH and TL
registers will read out as 0 (even if 1s are written to these bits), and the converted temperature will be
compared to the 10 MSbs of TH and TL.
The TH and TL registers and the POL bit are stored in EEPROM; therefore, they are NV and can be
programmed prior to installation of the DS1631. Writing to and reading from the TH, TL, and
configuration registers is achieved using the Access TH, Access TL, and Access Config commands.
Another thermostat feature is the temperature high and low flags (THF and TLF) in the configuration
register. These bits provide a record of whether the temperature has been greater than TH or less than TL
at anytime since the DS1631 was powered up. If the temperature ever exceeds the TH register value, the
THF bit in the configuration register will be set to 1, and if the temperature ever falls below the TL value,
the TLF bit in the configuration register will be set to 1. Once THF and/or TLF has been set, it will
remain set until over-written with a 0 by the user or until the power is cycled.
4 of 14

No Preview Available !

THERMOSTAT OUTPUT OPERATION Figure 3
Logic 1
POL=1 (TOUT is active high)
TOUT
DS1631
Logic 0
TL
TH Temp
CONFIGURATION REGISTER
The configuration register allows the user to program various DS1631 options such as conversion
resolution, TOUT polarity, and operating mode. It also provides information to the user about conversion
status, EEPROM activity, and thermostat activity. The configuration register is arranged as shown in
Figure 4 and detailed descriptions of each bit are provided in Table 6. This register can be read from and
written to using the Access Config command. Note that the POL and 1SHOT bits are stored in EEPROM
and all other configuration register bits are SRAM.
CONFIGURATION REGISTER Figure 4
MSb bit 6
DONE THF
*NV (EEPROM)
bit 5
TLF
bit 4
NVB
bit 3
R1
bit 2 bit 1
LSb
R0 POL* 1SHOT*
RESOLUTION CONFIGURATION Table 5
R1 R0 RESOLUTION CONVERSION
TIME (MAX)
00
9-bit
93.75ms
01
10-bit
187.5ms
10
11-bit
375ms
11
12-bit
750ms
START, STOP, AND ACK SIGNALS Figure 5
SDA
SCL
START
Condition
ACK (or NACK) STOP
From Receiver Condition
5 of 14